Exercise K

7/27/2019 Exercise K

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Exercise K Linear Contact Model

Finite Element Analysis in Practice Steps for Exercises 4.00 07/11/2005

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Exercise KLinear Contact Model

Brick Elements

Objective: Determine the stress in the assembly for a maximum clamping load of 1000 pounds applied at

the end of the lever.

Geometry: Use theExercise K.dmit file located in the "exercise K\input file" directory.

Loads: 1,000 pounds will be applied upward at the end of the lever.

Constraints: The four bolt holes and the top of the handle will be fully constrained.

One surface of the lever will be constrained against Z translation.Elastic boundary elements with a stiffness of 100 lbf/in will be applied in the X and Y directions

to the end of the lever.

Elements: Brick

Material: Handle, Base and Lever:Iron

Pins: Steel (ASTM A-36)


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Contact: The default contact is bonded. Three surface contact pairs should be created:1. Between the handle and the lever

2. Between the handle and pin

3. Between the lever and the pin


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SolutionMeshing the Model

Start FEMPRO from the Windows taskbar.

"Start: Programs:

ALGOR V17: FEMPRO"

Press the Windows "Start" button. Select the

"Programs" pull-out menu and the "ALGOR V17"

pull-out menu. Select the "FEMPRO" command.

"Open" Select the "Open" icon at the left side of the dialog

"ALGOR Direct Memory Image

Transfer Files (*.dmit)"

Select the "ALGOR Direct Memory Image

Transfer Files (*.dmit)" option in the ALGOR Files

section of the "Files of type" drop-down box.

Navigate to the directory where the model is located.

Exercise K.dmit Select theExercise K.dmit file in the "exercise K

\input file" directory.

"Open" Press the "Open" button.

"OK" A dialog will appear asking you to choose the designscenario for this model. Press the "OK" button to

accept the default of"Static Stress with Linear

Material Models" in the "Single analysis" field.

For the toggle clamp, the contact areas include the location of the two pins and the interface between

the lever and the handle. The default contact option of"Bonded" will be kept and three contactpairs will be created and changed to "Surface Contact". This type of contact will prevent the

surfaces from penetrating each other, but still allow them to pull away from each other with no

resistance.

Mouse Click on the heading for Part 1 in the tree view (the

lever).

Mouse Holding down the key, click on the heading forPart 3 in the tree view (the handle).

Mouse Right click on one of the selected headings.

"Create Contact Pair: Surface

Contact"

Select the "Create Contact Pair" pull-out menu and

select the "Surface Contact" command.


lever).

Mouse Holding down the key, click on the heading forPart 5 in the tree view (the pin connected to the lever).



Contact"




handle).


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Mouse Holding down the key, click on the heading for

Part 4 in the tree view (the pin connected to the

handle).



Contact"



"Mesh: Model Mesh Settings" Access the MESH pull-down menu and select the"Model Mesh Settings" command.

Mouse Move the slider to 60% of the default.

"Mesh model" Press the "Mesh model" button to create the mesh.

"No" Press the "No" button when asked to view the meshresults.

"Tools: FEA Editor" Access the TOOLS pull-down menu and select the"FEA Editor" command to move to the FEA Editor

environment to set up the analysis.

"OK" In the "Units Definition" dialog, press the "OK"

button to accept the default unit system of"English

(in.)".

Defining Element and Material Data

Mouse Click on the "Material" heading for Part 1 in the tree

view.

Mouse Holding down the key, click on the"Material" heading for Part 2 in the tree view.


Mouse Right click on one of the selected headings."Modify Material" Select the "Modify Material" command.

"Iron, Fe" Highlight the "Iron, Fe" item in the "Select

Material" section.

"OK" Press the "OK" button to accept the material selected

for Parts 1, 2 and 3.

Mouse Click on the "Material" heading for Part 4 in the tree

view.



"Modify: Material" Select the "Modify" pull-out menu and select the"Material." command.

"Steel (ASTM-A36)" Highlight the "Steel (ASTM-A36)" item in the

"Select Material" section.

"OK" Press the "OK" button to accept the material selected

for Parts 4 and 5.

After assigning the material properties, all red Xs should now be removed from the tree view.


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Adding Loads and Constraints

"View: Rotate" Access the VIEW pull-down menu and select the"Rotate" command.

Mouse Rotate the model until you can see the bottom of the

base.

"Selection: Shape: Point" Access the SELECTION pull-down menu and selectthe "Shape" pull-out menu. Select the "Point"

command. This will allow you select an object by

clicking on it.

"Selection: Select: Surfaces" Access the SELECTION pull-down menu and choosethe "Select" pull-out menu. Select the "Surfaces"

command. This will set a filter to allow you to select

surfaces.

Mouse Click on the inner surface of one of the bolt holes.

Mouse Holding down the key, click on each of theinner surfaces of each of the three remaining boltholes.

Mouse Right click in the display area."Add: Surface Boundary

Conditions"

Select the "Add" pull-out menu and select the

"Surface Boundary Conditions" command.

"Fixed" Press the "Fixed" button.

"OK" Press the "OK" button to apply these constraints.


Mouse Rotate the model until you can see the top of the

handle.

Press the key to exit rotate mode.

Mouse Click on the surface at the top of the handle.Mouse Right click in the display area."Add: Surface Boundary Condition" Select the "Add" pull-out menu and select the

"Surface Boundary Condition" command.

"Fixed" Press the "Fixed" button.



Mouse Rotate the model until you can see the side of thelever.


Mouse Click on the surface at the side of the lever.

Mouse Right click in the display area."Add: Surface Boundary Condition" Select the "Add" pull-out menu and select the

"Surface Boundary Condition" command.

Mouse Activate the "Tz" checkbox.



Mouse Rotate the model until you can see the short end of the

lever.



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Mouse Click on the surface at the short end of the lever.

Mouse Right click in the display area."Add: Surface Elastic Boundary" Select the "Add" pull-out menu and select the

"Surface Elastic Boundary" command.

"X" Select the "X" radio button in the "Direction"

section.100 Type "100" in the "Stiffness" field.

"OK" Press the "OK" button.

Mouse Right click in the display area."Add: Surface Elastic Boundary" Select the "Add" pull-out menu and select the

"Surface Elastic Boundary" command.

"Y" Select the "Y" radio button in the "Direction"

section.100 Type "100" in the "Stiffness" field.

"OK" Press the "OK" button.

"View: Rotate" Access the VIEW pull-down menu and select the

"Rotate" command.Mouse Rotate the model until you can see the long end of the

lever.


Mouse Click on the surface at the long end of the lever to

select it.

Mouse Right click in the display area.

"Add: Surface Force" Select the "Add" pull-out menu and select the"Surface Force" command.

1000 Type "1000" in the "Magnitude" field.

"Y" Select the "Y" radio button in the "Direction"

section to specify that the force will be applied in theY direction.

"OK" Press the "OK" button to apply the surface force.

Analysis

"Analysis:

Perform Analysis" Access the ANALYSIS pull-down menu and selectthe "Perform Analysis" command to run theanalysis. At the completion of the analysis, FEMPRO

will automatically transfer to the Results environment.

Viewing the Results

There are many options available in the Results environment to customize the presentation of results.For this exercise, the stress range and legend box font will be modified.

"Display Options:

Plot Settings "

Access the DISPLAY OPTIONS pull-down menu andselect the "Plot Settings" command.

Mouse Select the "Legend Properties" tab.

"Font" Press the "Font " button.


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"18" Select the "18" option in the "Size:" field. Note thatyou can also change the font to any of the TrueType

fonts listed.

"OK" Press the "OK" button to accept the changes to the

legend box font.

Mouse Select the "Range Settings" tab.

Mouse Deactivate the "Automatically calculate value

range" checkbox.0 Type "0" in the "Low" field.40000 Type "40000" in the "High" field. Any areas with

stresses larger than this value will now be rendered

using the highest color in the legend box (typically

red). It is common for users to set this value to the

yield stress of the material in order to quickly see whatareas of the model may have yielded.

"OK" Press the "OK" button and your presentation shouldnow look similar to the one shown in Figure 1.

Figure 1: Stress Results

This completes the exercise. To review a completed archive of this exercise, refer to the file

Exercise K.ach in the "exercise K\results archive" directory.


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Documents

Exercise K