The HEX shelter project report

the HEX shelterBucky Lab Design 2014-2015

Bayu PrayudhiPriyanka GanatraWan Yun Huang

Supervisor : Dr.-Ing. Marcel Bilow

Bayu Prayudhi - 4416368Priyanka Ganatra - 4409841Wan Yun Huang - 4421248

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IntroductionElevator pitch designGroup design developmentDesign component & Detail drawingsStructural mechanicsProduction processFinal resultSelf reflectionReferencesProduction technology

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06081230404453545556

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Introduction

This year Bucky Lab students will have a chance to face design and engineering problems of paper architecture. The Paper Architecture Group of Bucky Lab will focus on design of a shelter or home which will be built out of paper components.

The design task is to create a small living unit for two types of potential users: homeless people living in the cities and victims of natural or human made disasters like earthquakes, floods, wars etc.

The housing unit, depends on its destination should be designed as a lightweight easy to transport and preferably folding structure. Those designed for cities should take into account already existing urban structure and those for open landscape should be able to be combined in bigger group of units.

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Elevator Pitch Design

After the first weeks of the course, we had a presentation in which everyone have to present his idea within a 1 min one slide presentation – we call it the elevator pitch. Small models or material samples are allowed to illustrate our ideas and are very welcome if placed within the minute.

After a discussion round, half of the concepts will be selected to be further developed with groups of 2 or 3 till the end of the semester.

We were not expected to produce fully developed concept in detail for the elevator pitch, the idea has to show its potential in general and should convince the audience being worth to further developed within the semester.

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KARTSULE – Karton-Capsule, is a portable shelter fits for one person. Constructed fully with cardboard, it has a rotating mechanism which converts the 2.5 meter long shelter into a compact 0.4 - 0.5 width hexagon panel.

The concept was inspired by Japanese capsule hotel and the origami spring invented by Jeff Beynon. The Kart-Sule is lightweight, modular, and portable. It is suitable to use as a temporary sleeping space in an overnight event, such as music festival, instead of using a regular tent.

Bayu Prayudhi

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The concept for this project, is to build a relation between skin of the shelter and furniture inside.The shelter has to be portable and compact, as it is is going to be used during emergency crisis. For multi-use of space, the furniture within is movable in vertical direction,along y-axis.

Hence a bed can be used as a table or a bench. As the furniture moves, the outer skin expands and contracts. This expansion and contraction is possible, because the skin is made up of folded cardboard pleats.

Priyanka Ganatra

PRIYANKA GANATRA | 4409841

SECTION AA (OPTION 2)SECTION BB

The concept for this project, is to build a relation between skin of the shelter and furniture inside. The shelter has to be portable and compact, as it is going to be used during emergency crisis. For multi-use of space, the furniture within is mov-able in vertical direction, along y-axis. As the furniture moves, the outer skin ex-pands and contractsThis expansion and con-traction of the skin is possi-ble because it is made up of folded cardboard pleats.

Different top surface can be obtained be-cause of the move-ment. Hence a bed, can be used as a table or a chair

SECTION AA (OPTION 1)

free space

furniture

PLAN

AR1AE015-D1 BUCKY LAB DESIGN (2014-2015Q1)

CLUSTER FORMATION


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Fan shelter is a temporary shelter, which can be later on transformed into a permanent one by casting concrete into cardboard box foundation and the paper tubes in the structure. The main feature of the shelter is its chinese fan-shaped roof. It is designed to be open like a chinese fan and can be easily assembled.

The main material in this design contains paper tubes and honeycomb folding wall. The fan shelter is designed to be easily and fast assembled right after the disaster, and can be transformed into a permanent shelter when the refuges need to have long term settlement at the location.

Wan Yun Huang

Fan Shelter -From temporary to permanemt

Folding wall- for temporary use, it can be easily opened and closed; for permanent use, it can be as the insulation in the wall.

cardboard box

Cluster

Cardboard foundation& Concrete

concrete(permenent)steel joint

paper tube column paper tube beam

foundation section Joint perspective

Chinese folding-fan roof joint

Alice Wanyun Huang 4421248

Feature

-Chinese folding-fan roof-Folding wall-cardboard box foundation-paper tube plantation shelf

paper tube beam

paper tube main column

steel joint

paper tube plantation shelf

folding wall

cardboard box foundation

paper tube beam&column


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Group Design Development

As the human population grows, the need of shelter will always increase. Not only a permanent housing, but also in certain times human needs a temporary shelters. People sometimes lost their homes in an event like natural disaster or simply because of an economic situation. But sometimes we need a temporary housing when we are on vacation in remote areas, or when we want to see a three days concert but we don’t want to rent a room or sleep in a tent. A shop or market stalls are also a temporary shelter, where the shop owner spends half of the day selling their stuff.

HEX shelter tried to answer the problem of temporary shelter. We usually think the process of creating a shelter start from manufacturing pieces of the structure in the factory, transport the elements and materials to the site and assemble the shelter on site.

The assembly could be made so simple that it doesn’t need a professional help. Sometimes, the structure is also made to be easily disassemble allowing it to be reusable multiple times in other area.

Problem Statement

However, the time needed to assemble a temporary shelter is very critical in a post-disaster period. What if we eliminate the assembling process of a temporary shelter, while maintaining its portable and easily transportable size.

The core idea of this shelter is a deployable shelter that can be moved in seconds. Basically, it has two form, almost transformer-like shelter.

First, the compact-folded form. The criteria of this form is that it has to be lightweight, at least two person could carry it easily. It also need to be small enough to fit into a truck.

Second is the shelter form itself, it should provide a simple protection from the outside. The transformation process should be made as simple as possible without the need to remove any components or fixing elements of the shelter. As a multi-functional shelter, the design should allow it to be combined in a bigger group of units.

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Design references

1. Shelter Cart by Barry Sheehan and Gregor Timlin

2. Wheelly Shelter by Zo-Loft Architecture & Design

3. PUMP&JUMP by Jeong-Yun Heo

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Just like the building industry, paper and cardboard industry is a long established sector with extensive knowledge and experience. However, there are only few contacts between the two industries in the modern days.

Ancient Egyptian and Chinese cultures were the first to utilize paper as a building material in the form of papier màché. By the 2nd century B.C.E., they had developed papyrus.1 And by the 9th century A.D., the Japanese were using a paper element in the construction of sliding doors and walls, called shoji-fusuma, marking the first time paper was utilized as an interior building component.

Today, there are some architects that have made many attempts, in the past decades and also more recently, to use cardboard as a building material. Shigeru Ban is one of the few architect who successfully build projects which able to show that cardboard is an architecturally attractive material that has good properties in terms of structural and also acoustic properties.

Paper with a density greater than 200 g/cm3 is generally accepted as cardboard (also referred to as “carton”).2 Corrugated cardboard is a stiff, strong, and light-weight

[1] Therese Weber, The Language of Paper: A History of 2000 Years (Bangkok: Orchid Press, 2008).

[2] Ozlem Ayan, Cardboard in Architectural Technology and Structural Engineering: A Conceptual Approach to Cardboard Buildings in Architecture (ETH Zurich, 2009).

[3] Helen Gribbon, Florian Foerster. Structural Engineering and Design in Paper and Cardboard - Approaches and Projects. (TU Delft, 2008).

Cardboardas Material

material made up of three liner layers of brown kraft paper, a type of paper which is resistant to tearing, splitting and bursting, and is produced by using the kraft process of pulping wood chips. Composed of ply liners and a corrugating flute layer, corrugated cardboard is produced in a variety of Flute sizes (Type A to G/N, thicknesses ranging from 4.8 mm to 0.8 mm). Ply weights between 115g/m2 and 350g/m2 while corrugating flute weights around 112-180g/m2.2

Today, the vast majority of corrugated cardboard is used by the packaging industry, but it is also used for advertising board, various furniture applications, and the interior core of doors.

Cardboard, with all the accompanying knowledge already present from the cardboard industry, has a big potential to become a valuable part in architecture industry.

On the perspective of sustainability, cardboard is economical practical and it consist of almost 90% endlessly recycled material, which is considerable energy saving. Cardboard gives an option to throw away the material after it has reached the end of its life, without harming the environment.3

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Design references

1. Takatori Catholic Church by Shigeru Ban

2. Cathedral in New Zealand by Shigeru Ban

3. Cardboard Pavillion in TU Delft Faculty of Architecture

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Mechanical Behavior: Due to the characteristics of cellulose fibers and the bonds between them, paper has high tension strength, outperforming the strength of its compressive strength. As a byproduct of paper, corrugated cardboard is constructed as a sandwich structure that maximizes the bending stiffness of the board.1

Moisture Resistance: One major limitation of cardboard is that it becomes extremely weak when confronted with humidity or direct water, causing dimensional changes (swelling), distortion and reduced strength (tearing).

Acoustic Insulation Properties: Due to its low mass, acoustical qualities are not measurable for a single sheet of paper. However, extensive layering of corrugated cardboard (especially when combined with air vacuum systems) has been shown to provide significant acoustical insulation.

Thermal Insulation Properties: Cellulose fibers, the primary material used in cardboard production, are commonly used because of their low thermal

[1] Ozlem Ayan, Cardboard in Architectural Technology and Structural Engineering: A Conceptual Approach to Cardboard Buildings in Architecture (ETH Zurich, 2009).

conductivity in diverse industries (i.e. automotive, aviation), and are known to have strong insulation properties.

Fire Resistance: Untreated plain paper has no fire resistant qualities. However, paper boards containing heavy stocks of paper pulp exhibit some fire resistant characteristics, similar to untreated timber.

Biological Attacks: As with other wood and byproducts, paper and cardboard are sensitive to attacks by rodents, fungi and other bacterial development under certain conditions.

Toxicity: Despite the fact that cellulose fiber is derived from a natural resource, under certain conditions recycled paper byproducts can exhibit toxicity as a result of chemicals, bleaching agents, adhesives and inks used during production process.

Odor: Paper and cardboard do not release any odors but remain sensitive to foreign odors.

In terms of using it as building materials, cardboard has many advantages:

Low weight, lightweight materials have many advantages in construction process, transport, and reducing the need for human or mechanical energy.

Foldable/ printable, an essential characteristic in packaging industry. In building industry, these advantages are less obvious.

Recycling, the ecological advantage is very big. The raw material is infinite (cellulose fibre) and the cycle of old paper has an efficiency of 70%. However, the energy intensive recycling process does increase its impact on the environment.

Mass production, the bulk production has all the (dis-)advantages of the production process. The liquid and rolling phase (pulp and roll pressing) give us excellent opportunities to guide the properties of the material.

Low price, the raw material is very cheap. This means that we have a margin, by working the product, to achieve a cost efficient product or building part.

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Hanover Expo 2000 Pavilion by Shigeru Ban.

The building was conceived as a flexible grid shell structure that would be assembled and laid flat on the ground, and then lifted and formed into place by a protruding scaffolding system that would give it the final geometry.

The hall was totally recycled by the end of its seven month life.

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Function

The first idea of the design was to create a sleeping pod, almost like a tent, for one person. Inspired by Japanese capsule hotel. The space was made very efficient, perfectly fit as a sleeping space for one person. It is also possible to stack many of these capsule together to be even more efficient with space, this is basically the basic principle that generate the original idea of capsule hotel in Japan.

In the middle of the design phase, we asked ourselves, why not scale-up the shelter? We actually found more opportunities with this

new scale of the design.

Instead of being just a sleeping pod, it could become a modular micro dwelling, a portable space that is not only as a room to sleep, but the owner can use it as a social space, micro-shop stall, storage, study space, and anything that might possible. However, it still need to maintain its portable character by using lightweight materials.

The size was made close to a human scale size. The height of the shelter should be close to two meter, it will allows a person to stand easily inside the shelter. We

HEX Shelter as a modular micro-dwelling unit

put this idea as a basic criteria, because by being able to stand, it is easy as a person to take control of the space. The length of one module is also close to two meter, the proportion of the shelter is govern by the transition-rotation mechanism.

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Many function of HEX shelter:

Donut shop, lazy space, double bunk-bed room

Visualization of the HEX shelter complex

Comparison with the first idea of sleeping capsule

A large truck can fit up to 6 HEX Shelters, the Bucky Lab Light Van can fit 2 HEX Shelters

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Mechanism

The expansion mechanism was inspired by an origami model created by Jeff Beynon.1 It is a spring-like geometry made of a simple modular folding technique that created a rotation mechanism on a rigid paper, allowing it to change its shape similar to a spring.

The first attempt to test the idea of this transition-rotational mechanism was tested with a simple paper model. The paper was attached together using paper masking tape.

There are some basic principle of the rotation: To make both of the hexagon frame meet perfectly when folded, the rotation length must be 60, 120, or 180 degree.

The length of the folded paper must be the same with the chord length of the hexagon on the respective degree angle of the desired rotation.

120 degree rotation is the most suitable option for this design. If we do 60 degree rotation, the length of the shelter will be too short with an awkward proportion. 180 degree rotation will make a long shelter but it is impossible to do unless we do it only with flexible and thin material.

The unique part of this test model was that on folded form, the folded paper parts (brown colored) shaped almost like a camera aperture

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[1] Origami Spring into Action (Jeff Beynon). https://www.youtube.com/watch?v=aul0SzPVsls

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1. Origami spring model

2. Initial sketch paper model

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We were unable to determine how the tube was rotating. Hence the computer designed model was used to analyze the movement of tubes. Also the pivot point of rotation was tried at different points and we were able to optimize the design in terms of diameter of the tube and pivot point of rotation by using the 3d software.

We had an idea of using a ball joint that allows the beams to rotate freely in any direction. This study in grasshopper helps us to simulate the transformation of the model before we proceed further with the idea. We used a simple geometric model in Rhino with Grasshopper to study the geometry transformation and behavior when the transformation of the shelter occur. The model was built as a simple line-skeleton model which also used as a setting-out geometry to build the final model for presentation.

We will need 120 degree rotation where point A will meet point B. X is basically the height of the hexagon frame or the chord length of the hexagon on 120 degree angle. The formula for X is:

r is radius and A is the angle (120). The second hexagon is a translation with ‘move’ component by the result of the calculation above. In this case with 1200 radius, the distance between hexagon is 2078.46.

The model was constructed entirely in grasshopper, without any referenced geometry from Rhino. This process make it a lot easier to modify the model parametrically in grasshopper. Basically, we made two hexagon, one is stationary while the other one is moving for the transformation. The reference point is the world XZ-Plane, this point is the base plane for the first hexagon. The input for the polygon component are the radius and number of segments of the polygon. The distance between both hexagons was govern by the radius and how much rotation we wanted to make. The relationship of the dimension shown in this image:


Parametric Design Model

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To model the transformation, we need translation and rotation working on the second hexagon. The ‘move’ component was the translation. We need to make it controllable dynamically. The translation was done by changing the distance from 2078.46 to 0, while rotating it at the same time from 0 to 120 degree. We used a ‘number slider’ from 0 to 1 as a controlling parameter to control both of the transformation.

The lines connecting both hexagon was created by connecting the endpoints of all segments on each hexagon. ‘Explode’ component used to extract 6 segments of each components.

This model was already able to present the simulation of the transformation that we intended. However, to observe more in detail, we need to look at the behavior of one of the beam when the transformation occur.

We replaced the control slider with a ‘range’ component. Instead of having a single value as a parameter, now we have 10 value to see the transformation in 10 steps. We used ‘list item’ component to visualize only one of the six beams, and see the ten steps of its transformation.

From this simulation model, we can observe the transformation of the beams, where the length of the beams are changing, it gets smaller before it goes back to its original length. We could reduce this deformation by modifying the relationship of translation and rotation of the 2nd hexagon by using ‘graph mapper’ component.

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From this experiment, we conclude that even if we use a ball joint, it is not possible to achieve the transformation without having a shape deformation on the frames or on the tube beams. We agreed that the tubes have to be temporarily ‘detached’ from the frames when the transformation occur.

We had this idea of using cables placed inside the tubes, tensioned to both frames when it is on fixed shelter form. To transform the shelter, we need to somehow loosen the cable and detach the tube from the frame, allowing them to move freely with only the cables holding them.

From the setting-out model from the study before, we were able to model the full geometry of the shelter to study the design further and make decision in terms of detail elements of the design. For instance, we need to decide the thickness of the frames, dimension of the tubes, how the fabrics folds, and overall proportion of these detail elements.

The hexagon frames was modeled using ‘extrude’ component. The tubes are ‘pipe’ component applied to the lines geometry. The fabric is a simple straight-loft component connecting all centre lines of the six tubes together.

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Study Models

The tube is rotated in x-axis and z-axis. Because of this kind of rotation, many connections and joineries were considered.

On 1:5 model, we did a more detailed study on the connections and tested several ideas to make the rotation possible. These are the ideas we tried:

Masking tape is used initially to observe the rotational behavior of the cardboard panel. As it rotates in two axes, the tape would resist the movement and finally come out tearing the upper layer of cardboard sheet if lot of pressure was applied while folding it.

Zip ties These zip ties could be used to fix the cardboard triangular skin to the frame directly. But they obstructed three dimensional rotation. The zip ties helps to choose the flexibility of the assembly but only in one position. If it is too loose, the structure would be able to rotate and fold but in open position it will not stay stable. And if it is too tight then folding is not possible. Hence this kind of a joinery detail was not useful for this structure.

Hinges were again fixed to the hexagonal frame and the cardboard skin. The rotation with this kind of a joinery would only be in one axis like flaps closing and opening. Thus 3 axis rotation was not possible. Another disadvantage of this kind of assembly was that it has to be fixed using screws. This would be difficult to screw the hinge to the frame which is 155mm thick.

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Paper tube with strings. Finally, This was an option which helped easy movement while folding the structure. A cable is passed through a hollow tube. The tube is attached to the hexagonal frame with the help of this cable. As the tube is attached to the frame at a point because of the string, two-axis rotation is possible, compared to other connections which were rigidly attached to the frame.

But in this case, we were not able to achieve the stiffness of the overall structure when it is open. If the tube is tightly fixed to the frame then the structure will steadily stay in position, but rotation will be difficult. Hence, further this joinery was detailed out to make it flexible while folding and unfolding the structure.

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1:1 Detail Prototype

In order to hold the two hexagon frames firmly, the tubes needs to be tightly fixed to the frames. Hence, the tube is partly inserted in the frame by creating an aperture in the first ten layers of the cardboard which gives a depth of around 150mm. The cable also needs to be adjustable so that folding and unfolding is possible.

The cable inside the tube is tensed when the shelter is in open position. But when it needs to be folded and closed, the wire is loosened with the help of screws and the tube is removed from the frame.

The tube is fixed inside the frame using hexagonal wooden caps. These caps are used on both sides of the frame, so that the cable does not tear the cardboard while folding and unfolding the structure. The screw is rotated inside and outside the hexagonal cap. At the end of the screw again, a locking device is used so that the cable does not slide from the screw.

Detail of the cable tensioning mechanism

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1. Layers of corrugated cardboard was connected with paper glue

2. Detail of tube connection on the outer side

3. Detail of the cable end

4. Detail of the cable tensioning handle grip

5. 1:1 scale detail prototype

6. Detail of the cable tensioning without the grip

7. Study models of the shelter

8. First idea model of paper tube with strings

9. Study models with different types of connections

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The hexagon frame was constructed by layers of corrugated cardboard glued together to form a solid frame.

Hexagon outer radius: 1210mm

Hexagon inner radius: 1050mm

Thickness: 155mm

Developing process: Because the cardboard size is not big enough for the whole frame, so we divide them into different small pieces. In order not to make certain point to be the weak point, we make two different layers, which the division point is at different locations, and stack them together.This also helps to save the material significantly, as compared to cutting one entire frame together.

Design Components & Detail DrawingsHexagon Frame

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Elevation view of the shelter: Showing the dimension of the hexagon frames

2 types of hexagon layers stacked into 155mm thick layer of corrugated cardboard3 types of corrugated cardboard layers forming the hexagon frames, it was bonded with paper glue

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The tube beam is simply a custom paper tube attached to the hexagon frame with a tensioning cable inside the tube.

Length: 1895mm

Outer Diameter: 85mm

Inner Diameter: 80mm

Thickness: 5mm

Developing process: The main challenge we came across is actually how to make the tube stay in place after the structure is open. First, we only tighten the cable in the tube and lock it after the structure is in place. After testing it in the 1:5 model, we decide to make a hole with the depth of 4-layer cardboard in the hexagon frame so that the tube can fit into the hole when it needs to be locked.

Design Components & Detail DrawingsPaper tube beams with tension cable

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Details of the paper tube connection to the hexagon frames with steel cable tensioning device.

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Design Components & Detail DrawingsEnvelope Layer

The fabric envelope consist of a single layer of PEVA fabric attached to the tube beam and also supported with a triangular shaped one-layer of corrugated cardboard panel. The fabric is attached to the panel with Velcro and wrapped around the tube.

Developing process: The first thought for the skin of shelter is just to connect the panels together, first we thought about using stapler to attach the fabric to the cardboard panel,(we were not sure if the rotation will tear the fabric apart, and how elastic the fabric should be). In order to be waterproof and easy to assemble and replace, we decide to have the fabric wrapped around the tubes on each side.

However, we decided to use Velcro rather than stapler for attachment, for it can be easily replaceable whenever it is needed and would not damage the cardboard and fabric during the rotation. To stabilize and make sure the panel will stay in place, we made a rail on the frame, once the cable is tightened the panels will be place into the rail.

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Details of the envelope layers: Consisting of PEVA fabrics and corrugated cardboard panel.

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Design Components & Detail DrawingsDoor

The door is made of honeycomb cardboard, and at the upper and lower end of the panel, we use hinge as the rotating connection to connect it to the hexagon frame. As for the triangular panels on both side, we design to use flat cardboard bar to connect them to the frame.

Developing process: We had many ideas for shelter door design. At first , we try to make it like a Chinese fan in a folding structure, but due to it is not feasible to have the fix point in the middle of the hexagon, we gave up the idea.

For sure, the idea was followed by other alternative options like the mix of different triangular panels, hexagon rotating door. At the end, we try to make it as simple and functional as possible;that is, two rectangular door in the middle and fixed triangular panels on the side.

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Construction details of the door panels.

Door pivot atached to the hexagon frames

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Design Components & Detail DrawingsFloor

The floor is a sandwich layer of honeycomb cardboard panel and osb board, the floor is supported on each end by the hexagon frame. But during the construction, we found that it is not strong enough if without support in the middle. Therefore, we put one wooden support in the middle of the floor.

Developing process: In our design, we first try to use the material as light as possible, but at the same time it needs to be strong enough to support the weight of at least 2 people, therefore, we chose to use honeycomb cardboard as the floor material.

However, afraid that the pointed load,such as high heels, will damage the surface of the honeycomb cardboard, we decide to use OSB panel on the top of the honeycomb floor. In addition, the floor is designed to be hang up on the frame when it is not used, this way, it is not a separate element in this design project.

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Full span of the shelter

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Construction details of the floor and connection details to hexagon frames.

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Structural Mechanics

The drawing on the right shows the main structural skeleton of the shelter. The load of the fabric envelope carried by the cardboard tube beams and then distributed by the hexagon frame. The tension cable inside the tube beams help stabilize the structure from falling because of its own weight.

The floor is spanning across the both frames, supported by the cardboard frame structure on its end. There is an additional support in the middle of the floor to prevent too much deflection, or even worse, fracture on the floor if there are too many people inside the shelter. This floor structure is the part that we are going to discuss and analyze in this report. Do we need more support for the floor in between the hexagon frames? How many person at maximum it can carry?

Floor Material + Cross Sectional Properties

OSB Board:

Composition: Cellulose/Hemicellulose/Lignin/12%/H20/Adhesive

Thickness: 6 mm

Average Density: 550 kg/m3

Young’s Modulus: 1.8x109 N/m2

Compressive Strength: 16 MPa

Honeycomb Panel:

Composition: Kraft paper impregnated with phenolic resin

Thickness 25 mm

Average Density: 50.2 kg/m3

The above material properties information is derived from CES.

Floor area: 1.89 m2

Total volume: 0.069 m3

Total mass: 14.846 kg

Total weight: 145.49 N

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Structural diagram

For the floor we have to determined how many intermediate supports are required. Initially, there are two pin supports at both ends. This is done by comparing the bending stress of the composite to its compressive strength. Deflection caused in different cases of the section is also determined. The floor spans in one direction. Hence, we have found bending moment, bending stress and deflection using beam calculation method. Since the floor is a composite, we will first find the second moment of Area(I), using Parallel Axis Theorem.

We have assumed self load of the floor and the load of four people each weighing 70 kg. Hence the load of 70x4x9.8= 2744 N is uniformly distributed throughout the beam.

Live Load = 70x4x9.8 = 2744N

Self Load = Density x Volume x Gravity = 550x(1.8x1.05x0.006)x9.8 = 61.12Nx2 = 122.24N

Total Load = 2866.24N

Total Load/meter = 2866.24/1.8 = 1592.35N/m

Total Load/meter2 = 2866.24/1.8 = 1516.53N/m2

It is not possible to calculate a sandwich plate construction in Diana. Thus, we need to define a representative structure as an input for calculation. Since the difference in stiffness of OSB board and honeycomb board is quite big, we can omit the stiffness properties of honeycomb board. However, we will need a new thickness for the representative structure. The second moment of area for plate is calculated and from that the new thickness of the floor is determined. This is done as it was difficult to input a composite section of the floor in diana.

Ip = (t3/12 + txd)x2 = 2.58x10-9m4

New thickness (T) = 3Ip12 = 0.014m

Now, using this thickness,

I =wT3/12 = 1.05x0.0143/12 = 2.4x10-7 mm4

Case 1: Floor with two supports

Case 2: Floor with three supports

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In this case, we consider loads of four people and self weight of the floor, keeping the supports only at two ends.

- Beam Calculations:

Support Reaction = RA = RB = 1592.35/2 = 796.17N

Deflection = 5ql4/384EI = 5x1592.35x1.84/384x8x108x2.7x 10-7 =0.4463m

Bending Moment (Mmax) = ql2/8 = 1592.35x1.82/8 =644.905 N-m

Bending Stress () = My/I = 644.90x0.007/2.7x10-7= 18.80x106N/m2 =16.664 MPa

The Bending Stress () exceeds the compressive limit i.e. 16MPa. Hence the structure is not safe when there are people standing on it and needs additional supports.

When comparing hand calculations with diana calculations, the bending moment is divided by width (1.05m) of plate, as in diana bending moment for a plate is calculated.

Bending Moment (Mmax)= 644.905 /1.05=614.1954N-m

- Plate Calculations:

The ratio of the plates length:width 1.8

Therefore, constant c1 = 87, constant c2 = 26

mxy = 0.001xqxlx2xc1 = 0.001x1592.35x1.052x87 = 152.73 N

myy = 0.001xqxlx2xc2 = 0.001x1592.35x1.052x26 = 45.64 N

Hand calculation

Diana calculation

Difference (%)

Deflection 0.446 m 0.456 m 1.87%

Bending moment

614 N-m 628 N-m 2.26%

From the above table of hand calculation and Diana results, we can see that the difference between them are small. For deflection, the difference is only 1.87% different; as for maximum bending moment is 2.26% of difference. The existence of the small difference is the density of the mesh, as more fine the mesh is, the difference between the hand calculation and Diana will be close to 0.

In this case, the floor is only supported by the frame on two side. From the calculation we can see that both deflection and bending stress exceeds the serviceability limit state and ultimate limit state respectively, which means the floor will collapse with only frame supports.

Floor with 2 supports

Support reaction forces

Deflection

Bending moment X-plane direction

Bending moment Y-plane direction

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In this case, we consider loads of four people and self weight of the floor, but insert an additional support at the center.

- Beam Calculations:

Deflection = ql4/185EI = 1592.35x0.94/185x8x108x2.7x10-7 =0.01158m

Bending Moment (Mmax) = ql2/8 = 1592.35x0.92/8 =153.5 N-m

Bending Moment (M1) = 9ql2/128 = 9x1592.35x0.92/128 = 86.37 N-m

Bending Stress () = My/I = 161.22x0.007/2.4x10-7 = 4.7x106N/m2 = 4.166MPa

With one support in the middle of the plate, the Bending Stress () is now within the compressive stress 16MPa of OSB board.

- Plate Calculations:

The ratio of the plates length:width 1.8

Therefore, constant c1 = 87, constant c2 = 26

mxy = 0.001xqxlx2xc1 = 0.001x1592.35x0.92x87 = 112.21N

myy = 0.001xqxlx2xc2 = 0.001x1592.35x0.92x26 = 33.53 N

Hand calculation

Diana calculation

Difference (%)

Deflection 0.01158 m 0.0118 m 1.85%

Bending moment

153.54 N-m 129 N-m 19.03%

In this case, the difference between the hand calculation and Diana results on bending moment is surprisingly big, 19.03%. Therefore, We think the reason behind it can be the inaccuracy of hand calculation formula itself, that hand calculation can not represent the most accurate results; on the other hand, the finer the mesh is the results will be closer to the reality as well.

As for the deflection 1.15 cm of the floor , the result is within the serviceability limit state i.e.0.6cm , which reduces immensely from 45.6 cm in previous case. In addition, the bending stress 4.16 MPa is also within the ultimate limit state of OSB board compressive stress 16 MPa. Therefore, with one support in the middle of the OSB board is an ideal solution for the floor structure.

Floor with 3 supports

Support reaction forces

Deflection

Bending moment X-plane direction

Bending moment Y-plane direction

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Production Process

Material Estimation

The cardboard-related material was provided by a Polish company Packprofil.pl, they have to send the material all the way from Poland so we have to carefully estimate our material needs so that we would have enough material for our pavilion. It was quite simple to tell how many cardboard tube and honeycomb panel we need.

However, it is not that simple to calculate how many pieces of corrugated cardboard that we need, we have to digitally simulate

it. We informed that the size of the corrugated cardboard is 1.2m x 2m. Using Rhino, we plotted the shape of cardboard pieces that we need and arrange them in the most efficient way, with as little waste as possible.

This method allows us to simply calculate how many layers of corrugated cardboard that we need and we add additional 15% amount of cardboard panels for back-up.

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Production Process

Schedule Planning

Before the building week, we made a schedule for the construction. In our first schedule, it is planned by the assumed workload and the priority of the whole project. However, during our building week, we didn’t fully follow the schedule, and it is because that some process took longer than we expected.

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Production Process

Building WeeksDay 1:Fabrics

It’s the first day of building week! The paper tubes we ordered wasn’t delivered. In our original design, we ordered 88mm outer diameter, 8mm thick tube, so for the alternative option we decided to replace them by 2 different sizes of paper tubes. The upper 4 tubes are 85 mm tubes and lower 2 tubes are 95 mm diameter tube.

First, we started working on cutting the shower curtain, which is used as the skin for the shelter. At the mean time, we are trying to use sewing machine to sew the fabric, but after few attempt, we found that sewing is not needed, because the the edge of shower curtain was not as rough as we expected.

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Production Process

Building WeeksDay 2:Plywood

Today, we start sticking Velcro on the fabric, which is only the wrapping part of the fabric. At the same time, the wooden cap is on its way. First, we try to make them into circular shape, just like we what we design in the drawing, but it took longer than we expected and was not easy to make it into a perfect circular shape.

After consulting with Marcel, he advised us to make it into hexagon shape, which will be easier in production. We used one of the big wood cutting machine to make the wooden cap for the tube, we made many different sizes of hexagon wooden cap in a day. In the afternoon session, we also started to produce the hexagon frame by using jigsaw.

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Production Process

Building WeeksDay 3-5:Hexagon Frame

From day 3, the whole construction is mainly about making the hexagon frames. Cutting the cardboard with jigsaw took quite some time. Although we use clamp to make the stake of cardboard fix on the table, it still needs two people to finish the cutting process: one holding jigsaw and the other one holding the cardboard panels to reduce the vibration which caused by the jigsaw.

Simultaneously, we started to make hexagon holes on the frame by using a drill and a jigsaw and also working on the wooden caps, including drilling and sanding.

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On day 5, we were finally at the stage of gluing stacks of cardboard frame together. However, Benjamin from the other group advised us not to do glue them all together at once, but glue them in separated layers.

We made our first attempt to glue layer by layer for the whole frame, but it failed because the uneven gap. Eventually, we came up with an idea of making 6 corner pieces first then connect them all together.

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Production Process

Building WeeksDay 6-8:Building The Shelter

From the second week of building weeks, we began with gluing the second hexagon frame. at the same time, we were also working on putting cable through the tube and the frame. For the wooden cap, sanding and final finishing fitting for the hole in the frame is underway.

Finally, the cable tighteners are assembled. The final step for the skin is to attach fabric and the cardboard by Velcro, and to wrap it around the tube. since the tube size has been adjusted, velcro need to be relocated.

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Production Process

Building WeeksDay 9:Rotation Test

Generally speaking, the rotation test is successful. it took 6 people to finish the whole rotation process. First, we loosen all the cables at 6 points of each frame, then 2 people held one frame to stay in place, and the other 2 people held the other frame to do the rotation.

During the rotation, one piece of the fabric fell due to it is not well attached to the tube. Also, one of the cable broke, due to the cable is not loose enough. In addition, because the thickness of the panels and fabric, the folding form is not as thin as we thought. But as structure itself, the rotation to the folding position is working really well.

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Final Result

HEX Shelter:Portable micro-temporary dwelling unit

The aim of this project is to create a temporary shelter that is portable, lightweight, and cheap. Cardboard as an environmentally friendly material gives answers for the lightness and the affordabilty of the shelter. The expand-rotation mechanism answers the portability needs.

The height of the hexagon frames is 2.1m, it has an outer diameter of 2.4m. The total length of the shelter is 2.2m. In its folded portable position, the length is only about 700-900mm. The shelter was light enough for two adults to carry. And the floor of the shelter was strong enough to hold 5 person inside the shelter.

The shelter has a fabric envelope which is waterproof and semi-translucent, allowing some diffused light to pass through. The triangular cardboard panel on the fabrics allows the shelter to rotate only in one direction.

The cable tension mechanism is strong enough to hold the frames together. In general, the primary structure of the shelter is the hexagon frames, any other added elements for the shelter should be carried by the frames.

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During the building week, we found that many construction process is not as simple as what we expected, not to mention doing this 1:1 relatively big structure. The following are some points that we think it can be improved:

The limited amount of time and materials we had causing us to do many improvisation which differs from the original plan and design. We didn’t manage to make the door, and the floor is a separated element from the shelter. The original ideas was to have a folding floor, we want the whole thing to be integrated with the shelter without any separated elements. We also didn’t manage to make the handle grip for the cable tension mechanism, even though we could say that it is in some way an aesthetic elements, it took a longer time to loose the cable without the grip.

The length of the cable: During the rotation test, we found that it will be easier to rotate the structure if the cable is more loose. However, we couldn’t get this extra length of cable because the length of the loose and tensioned cable is govern by the cable adjuster which we could only found in a bicycle shop. It was very difficult to find this unique part in the dimension that we desired, we could custom-made it with a 3D printer, but we thought that the strength of ABS

Self Reflection

plastic is not enough to sustain the compression load of the cable.

Stronger velcro : In our prototype, the attachment between panel and fabric is not strong enough, so that the fabric may easily fall especially during the rotation. For the improvement, the industrial-use velcro is needed and velcro should be attached all the way along the edge of each panel.

It was difficult to rotate the entire assembly because of the scale of the structure. We assumed that the structure can be rotated by 2-3 people. But we needed at least two people to hold one frame. The fabric and the cardboard skin created some kind of resistance and obstructed the easy movement of rotation as experienced in smaller scale models. The solution to this is, when folding the structure, the entire skin needs to be dismantled and then rotated.

Overall, we are very satisfied with the whole process and the final result of the workshop. We agree that the shelter design is looking very elegant with its combination of cardboard and PEVA fabrics. The proportion of the shelter was exactly the same as what we expected. We are very optimist with the idea of cardboard as architectural material and we would love to see further research and workshop on the subject.

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References

Latka, F. J. Paper Spatial Structures. Faculty of Architecture, Wroclaw University of Technology, 2013.

Dooren, V.E. and Verheijen, F., Cardboard in Architecture; an Overview. Delft: IOS Press, 2008

Kranenburg, V.K., Dooren, V.E. and Veer, F. The Design and Building Process of a Cardboard Pavillion. Delft: IOS Press, 2008

Dooren, V.E. and Iersel, V.T. A House of Cardboard. Delft: IOS Press, 2008

Gribbon, H. and Foerster, F. Structural Engineering and Design in Paper and Cardboard - Approaches and Projects. Delft: IOS Press, 2008

Schönwälder, J. and Rots, J. Mechanical Behaviour of Cardboard in Construction. Delft: IOS Press, 2008

Eekhout, M. The Cardboard Dome as an Example of an Engineers Approach. Delft: IOS Press, 2008

Therese Weber, The Language of Paper: A History of 2000 Years (Bangkok: Orchid Press, 2008).

Ozlem Ayan, Cardboard in Architectural Technology and Structural Engineering: A Conceptual Approach to Cardboard Buildings in Architecture (ETH Zurich, 2009).

Jeff Beynon, Origami Spring into Action. https://www.youtube.com/watch?v=aul0SzPVsls

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Production Technologies AR1AE015 –D3 / How It works

Bayu Prayudhi

CHAINSAW

Chainsaw is a tool that revolutionize the logging industry by replacing the human muscle power to mechanical power. Basically it is a portable mechanical saw with a set of teeth attached to a rotating chain which can cut tree easily.

In general, a chainsaw has two main parts: a saw blade built into a chain, wrapped around a long metal guide bar, and a one-cylinder gasoline engine (some models use an electric motor with battery). Chainsaw machine converts the chemical energy locked in gasoline into mechanical energy we can use to cut timber, turning a tree into logs.

How a chainsaw works:

1. The fuel tank holds 0.5 liters of gasoline, this is the energy source we need to cut down and chopping up logs.

2. The fuel feeds through a carburetor to mix it with air.

3. The air-fuel mixtures passes into a cylinder, which works much like the ones in a car engine but with only a simple push-pull (two-stroke) action instead of the more complex (four-stroke) cycle used in a car. Inside the cylinder, the air-fuel mix is ignited by a spark plug, burns, releases its energy, and pushes a piston back and forth. The piston in a chainsaw engine has a diameter about 45mm and a stroke about 33mm, so it is less than half the size of a

typical car engine piston and moves only half as far.

4. A connecting rod and crank convert the back and forth motion of the piston to rotary motion.

5. A drive shaft takes power to the centrifugal clutch.

6. A chainsaw engine runs all the time, but we don’t want to waste energy and avoid risk of the dangerous blade chain out of control. The clutch solves the problem. The centrifugal clutch connects the engine and the chain when the engine speed is

fast (when the operator pulls on the throttle) and stops the chain from spinning when the engine speed is low (when the chainsaw is just idling).

7. Gears carry power from the clutch to the sprocket that holds the chain.

8. The chain spins around the edge of a long-steel plate called the guide bar, doing the work of cutting down the trees.

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Centrifugal clutch

In a chainsaw, the clutch means you can keep the engine running all the time and simply disengage the chain (so it stays safely motionless) when the saw isn’t actually being used. Chainsaws use a centrifugal clutch, which automatically engages when the engine spins at high speed (when the saw is actually chopping wood) and disengages when it’s running more slowly or idling. A centrifugal clutch is really simple and consists of just a few parts. There’s an inner drive shaft which linked directly to the engine and

spinning all the time when the engine is running and an outer rim positioned around it which connected to the chain sprocket. In between them are mechanical arms, connected to the inner shaft, that fly outward at high speed with centrifugal force, locking the inner and outer parts of the clutch together.

Advantages

The main advantages of using a chainsaw is speed. Rough estimation is working with a chainsaw can be 10 times quicker than an ordinary hand saw. It does

the job quickly and does not need a lot of man hour compared to manual human force with a hand saw.

Disadvantages

The biggest drawbacks of chainsaw are safety and maintenance. Although chainsaws can be used by any fairly strong adult after suitable training, they are still very dangerous. The biggest risk comes from a problem called kickback, where the chain catches on something but the engine keeps turning, so the whole saw flies up and backward toward the operator’s head, potentially causing fatal injuries.

Another big problem with chainsaws is the amount of maintenance they need. A handsaw is basically maintenance free. While in chainsaw, the fine dust from the wood can get caught up in the mechanism and mix with the chain’s lubricating oil that has to be cleaned out regularly.

Source:

TR56 - How It’s Made Chainsaws https://www.youtube.com/watch?v=Q_nGmcc7eKs

http://home.howstuffworks.com/chainsaw1.htm

http://ankn.uaf.edu/publications/VS/chainsaw.html

http://www.gardengrapevine.com/ChainsawCarbRepair.html

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Priyanka Ganatra

CARDBOARD TUBE

The entire process of producing spiral winding paper tube is an automated process. It is made of paper sleeves.

• First, rolls of paper sleeves are stacked together for the process to begin. The number of rolls or sleeves going through the process depends on the desired thickness of the tube. Then these sleeves are adjusted through different stages to achieve a particular angle.

• This is done because before the gluing stage it needs to be separated from each other and form a cascade. As a result, the glue reaches from top to the lowermost sleeve without any manual or mechanical process. After the adhesive is applied, the paper sleeves immediately passes through rollers which spread the adhesive evenly. This is important as any air gaps affect the mechanical properties of the tube.

• In between different stages it is pressed with rollers to avoid any wrinkles. After the gluing it has to come together at a predefined angle. It is winded to the core as an entire ply and not separately. Therefore the sleeves come together as a hand fan and then starts winding to the core. The winding table moves along the bed of the machine so that the winding belt moves clear of the last ply as more plies are added. With a stabilized

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belt drive high radial pressure is ensured on the tube and a better pulling of the paper plies, without slipping.

• This is a continuous process and the number of winds does not determine the length of the tube (only the thickness). The tube finally undergoes cutting stage where the final product is achieved.

source:

https://www.youtube.com/watch?v=xHbWdB3QnWo

https://www.youtube.com/watch?v=m7nzCQ8jkOU

https://www.youtube.com/watch?v=CLyTsaGsbfA

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Component:

1. Elevator car: where people and goods can be loaded.

2. Counterweight: it is acted to keep elevator car in balance. The weight of the counterweight is about 40-50 percent of full capacity of the car. That is to say, when the car is filled to 40 percent capacity, the counterweight and the car is in balanced.

3. Sheave: With these roping systems, loads on the rope is reduced to 1/2 or 1/4 as well, hence the diameter and number of ropes can be reduced.

4. Electric motor: it is connected to the sheave to operate the rotation of the sheave.

5. Guided rail: Both the elevator car and the counterweight ride on guide rails


Wan Yun Huang

THE ROPING ELEVATOR

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Mechanic system:

There are various elevator systems, such as the roped system and hydraulic system. However, roping system is more popular in elevator design. In the roping system, the car is raised and lowered by traction steel ropes. One side of the rope is attached to the car, goes around the sheave and the other end is attached to the counterweight.

The motor is connected to the sheave to control its rotation, so when the sheave rotates, the car will be raised or lowered. Roping elevators are much more versatile than hydraulic elevators, as well as more efficient. Typically, roping system also has more safety systems.

Safety system:

Rope system:

Typically the elevator is supported by 4 to 8 ropes , which supports the car and the counterweight, but actually each rope can support the system on its own. So if unfortunately one rope snaps, other ropes can still operate the system.

Safeties:

Safeties are activated by a governor when the elevator moves too quickly, for instance, if all the ropes were snapped off. In the governor, the sheave is attached to two hooked flyweights that pivot on pins. As the elevator car falls really fast,

the governor speeds up as well, which centrifugal force moves the flyweights outward, pushing against the spring. This works to stop the governor, as the elevator will stop as well.

source:

How stuff works:

http://science.howstuffworks.com/transport/engines-equipment/elevator.htm

Documents

The HEX shelter project report