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2009-20102009-2010

FINAL YEAR PROJECTFINAL YEAR PROJECT

DEPARTMENT OF MECHANICAL ENGINEERINGDEPARTMENT OF MECHANICAL ENGINEERING

A.V.C COLLEGE OF ENGINEERING A.V.C COLLEGE OF ENGINEERING

:

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CRASH ANALYSIS OF S-RAIL

ASSEMBLY IN AUTOMOBILES

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PROJECT GUIDE :PROJECT GUIDE : INTERNAL GUIDE:INTERNAL GUIDE: Mr. A.BALAJI, M.E.,Mr. A.BALAJI, M.E., LECTURER IN MECHANICAL LECTURER IN MECHANICAL

DEPARTMENTDEPARTMENT A.V.C COLLEGE OF ENGINEERING . A.V.C COLLEGE OF ENGINEERING .

EXTERNAL GUIDE:EXTERNAL GUIDE: Mr. A.BALAJI, M.Tech.,Mr. A.BALAJI, M.Tech., PROJECT MANAGERPROJECT MANAGER

CHETROIT TECHNOLOGIES. CHETROIT TECHNOLOGIES.

PROJECT STUDENTS :PROJECT STUDENTS :

A.SUDHAN 80106114313 S.SELVAMUTHUKUMARAN 80106114037 N.VIMALBARATH 80106114043 R.VINOTHKUMAR 80106114045

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FLOW OF PRESENTATIONFLOW OF PRESENTATION► COMPANY PROFILECOMPANY PROFILE► ABSTRACTABSTRACT► PROBLEMSPROBLEMS► OBJECTIVESOBJECTIVES► SOFTWARE USEDSOFTWARE USED► METHODOLOGYMETHODOLOGY► APPLICATIONSAPPLICATIONS► FUTURE SCOPE OF THE PROJECTFUTURE SCOPE OF THE PROJECT► CONCLUSIONCONCLUSION► REFERENCEREFERENCE

COMPANY PROFILECOMPANY PROFILE  

  CHETROIT TechnologiesCHETROIT Technologies is one of the fastest growing is one of the fastest growing

company providing engineering solutions using company providing engineering solutions using innovative engineering applications. We provide end-to-innovative engineering applications. We provide end-to-end solutions from conceptualization, engineering end solutions from conceptualization, engineering design and analysis. design and analysis.

Our expertise in diverse engineering applications Our expertise in diverse engineering applications influences the customers to attain their objectives influences the customers to attain their objectives beyond their expectations with high quality services. We beyond their expectations with high quality services. We also focus in Training & Development in CAD/CAM/CAE, also focus in Training & Development in CAD/CAM/CAE, intensive industrial oriented training according to intensive industrial oriented training according to current requirements with project experience & design current requirements with project experience & design concepts for corporate and engineering students.concepts for corporate and engineering students.

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ABSTRACTABSTRACT

S-rails in vehicle structure are the main energy-S-rails in vehicle structure are the main energy-absorbing components in case of frontal collision. absorbing components in case of frontal collision. Optimal crashworthiness design of such components is Optimal crashworthiness design of such components is one of the crucial tasks in designing crashworthy one of the crucial tasks in designing crashworthy vehicles. vehicles.

In this paper, an S-Rail impact model is extracted In this paper, an S-Rail impact model is extracted from a true rail used in a vehicle frame. Response surface from a true rail used in a vehicle frame. Response surface method coupled with genetic algorithm is presented and method coupled with genetic algorithm is presented and utilized to obtain optimal crashworthiness design. utilized to obtain optimal crashworthiness design.

The method adopted in this research makes use of The method adopted in this research makes use of design of experiments (DOE) and numerical optimization design of experiments (DOE) and numerical optimization algorithms.algorithms.

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The nonlinear explicit finite element code The nonlinear explicit finite element code PAM-CRASH was used to conduct the rail impact PAM-CRASH was used to conduct the rail impact problems and generate the energy functions to problems and generate the energy functions to be maximized. be maximized.

Several design parameters like the cross Several design parameters like the cross section width, cross section height and the section width, cross section height and the curvature angle have been proposed and used curvature angle have been proposed and used to optimize the S-railpsilas structure. to optimize the S-railpsilas structure.

The results indicated the promising The results indicated the promising capabilities of the proposed optimal design capabilities of the proposed optimal design method for the energy-absorbing of S-rails.method for the energy-absorbing of S-rails.

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REASON FOR CHOOSING THE PROJECT

►During collision shock is transferred to whole body of the automobile structure.

►In conventional S-rail, it can not absorb more energy.

►More impact will affect the passenger.►It leads to failure and loss of life of the

passenger

OBJECTIVES

►To reduce the shock impact transferred to whole body of the automobile structure.

►By using modified S-rail, kinetic energy is absorbed in front of the body of automobile during accident.

►To save the life of the passenger who are in the automobile.

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SOFTWRAE USEDSOFTWRAE USED

►CATIA V5 CATIA V5 – Modeling purpose.– Modeling purpose.

►HYPERMESH HYPERMESH – Meshing purpose.– Meshing purpose.

►ABAQUS ABAQUS – Running the – Running the project project and result and result viewing.viewing.

THE AUTOMOBILE STRUCTURE

S-RAIL

S-RAIL ASSEMBLY

S-RAIL DEFINITIONS-RAIL DEFINITION

S-Rail assembly is a vehicle S-Rail assembly is a vehicle structure that can absorb the crash structure that can absorb the crash energy by controlled vehicle energy by controlled vehicle deformations while maintaining deformations while maintaining adequate space so that residual crash adequate space so that residual crash energy can be managed by the energy can be managed by the restraint systems to minimize crash restraint systems to minimize crash loads transfer to the vehicle loads transfer to the vehicle occupants.occupants.

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Introduction of crush Introduction of crush InitiatorsInitiators

► The existing design for S-Rail assembly plays an important role in The existing design for S-Rail assembly plays an important role in absorbing the impact during a crash. But there is always a need absorbing the impact during a crash. But there is always a need for improvement. The makers are constantly looking for more for improvement. The makers are constantly looking for more efficient and better design which reaps more results with less efficient and better design which reaps more results with less change in the existing design.change in the existing design.

► For the existing design of S-Rail assembly, the kinetic energy during a For the existing design of S-Rail assembly, the kinetic energy during a crash is absorbed when the bending of the S-Rail occurs. Here, we are crash is absorbed when the bending of the S-Rail occurs. Here, we are introducing a few crush initiators, whish initiate the axial crushing or introducing a few crush initiators, whish initiate the axial crushing or collapse of the front part of the S-Rail assembly, when it collides with an collapse of the front part of the S-Rail assembly, when it collides with an obstacle. The part where the axial collapse occurs is known as the ‘Crash obstacle. The part where the axial collapse occurs is known as the ‘Crash zone’. In an S-Rail assembly, the axial collapse occurs till zone’. In an S-Rail assembly, the axial collapse occurs till the crash zone the crash zone ends and the usual bending occurs afterwards. In this new design ends and the usual bending occurs afterwards. In this new design of S-Rail assembly, energy is absorbed by the both axial collapse of S-Rail assembly, energy is absorbed by the both axial collapse and bending. This improves the efficiency of the S-Rail assembly and bending. This improves the efficiency of the S-Rail assembly in the absorption of the kinetic energy, during a crash.in the absorption of the kinetic energy, during a crash.

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SIDE AND FRONT VIEW OF S-RAIL ASSEMBLY WITH OUT CRUSH SIDE AND FRONT VIEW OF S-RAIL ASSEMBLY WITH OUT CRUSH INITIATORSINITIATORS

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SIDE AND FRONT VIEW OF S-RAIL ASSEMBLY WITH CRUSH INITIATORS

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METHODOLOGYMETHODOLOGY MODELING USING

CATIA V5

MESHING USING

HYPERMESH

RUN & RESULT VIEWING USING

ABAQUS

PREPROCESSING

PROCESSING

POST PROCESSING

Preprocessing

In this project we are meshing the S-Rail assembly in HyperMesh in Altair hypermesh 8.0. Abaqus elements are used in the HyperMesh. The CATIA model, saved in IGES file format, is imported to HyperMesh. After improving, the mid-surface is selected from the ‘geometry’ page and the ‘extract command is given after selecting the component to be meshed. After this the 2D page is selected and ’automesh’ is given. Here shell meshing is done and the element size is given. Then the meshed component is then saved with INP extension.

Solving and post processing:

In this project, we are doing the solving and post processing work ABAQUS version 6.5 software. The component is imported to ABAQUS. The material properties such as young’s modules, yield strength, etc is given in ‘property’ module. After this, the ‘assembly’ module is selected and the parts, which are to be solved, are selected. Following this, the ‘step’ module is selected and the dynamic, explicit method is selected for solving the job. The boundary conditions and initial parameters are given in the ‘load’ module. After this the job module is selected and the, to be solved, is submitted for solving. The simulation is done in the ‘visualization’ module and it is saved in a video format.

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CATIA model of front S-Rail assembly without crush CATIA model of front S-Rail assembly without crush initiatorsinitiators

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CATIA model of front S-Rail assembly with crush CATIA model of front S-Rail assembly with crush initiatorsinitiators

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CATIA model of the BarrierCATIA model of the Barrier

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MATERIAL PROPERTIES

Linear Material properties :

Young’s modulus = 210000MPa

Poisson's ratio = 0.3

Non Linear Material properties :

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No of elements : 656

Type of element : S3R, S4R Deformable elements

Element size : 30mm

FEM model – S-rail without crush initiators

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FEM model – S-rail with crush initiators

No of elements : 1922

Type of element : S3R, S4R Deformable elements

Element size : min 10 max 30mm

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FEM model – Barrier

No of elements : 35

Type of element : R3D4, R3D3 Rigid elements

Element size : 30mm

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Boundary conditions

All degrees of freedom arrested

Edge nodes are given 30KMPH velocity in the crash direction. Same nodes are arrested in translations in other direction.

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Deformation video of S-rail without crush initiators

wo_crack_initiatiors.avi

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Deformation video of S-rail with crush initiators

with_crack_initiatiors.avi

with_crack_initiatiors.avi

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Von misses stress plot without crush initiators

Before Crash After Crash

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Von misses stress plot with crush initiators

Before Crash After Crash

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time steptime step(sec)(sec)

Reaction forces in crash direction (-y direction)Reaction forces in crash direction (-y direction)(Newton)(Newton)

without crashwithout crashinitiatiorsinitiatiors with crash initiatorswith crash initiators

1010 2020 1818

2020 1212 2020

3030 3838 6060

4040 6060 8080

5050 3535 9090

6060 7070 8080

7070 102102 9090

8080 160160 150150

9090 170170 200200

100100 201201 260260

110110 204204 320320

120120 201201 360360

130130 204204 390390

140140 205205 420420

150150 210210 430430

Reaction forces table

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GRAPHGRAPH

050

100150200250300350400450500

10 20 30 40 50 60 70 80 90 100 110 120 130 140 150

Series1

Series2

FORCE(N)

DISTANCE(MM)

SERIES 1 – WITHOUT CRUSH INITIATORSSERIES 2 – WITH CRUSH INITIATORS

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APPLICATIONSAPPLICATIONS

►It is used in variety of small segment and medium segment luxury cars, like Ambassador, Maruti 800, Toyota Qualis, TATA Sumo, etc.,

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FUTURE SCOPE OF THE PROJECTFUTURE SCOPE OF THE PROJECT

► Here after all the vehicles are equipped with Here after all the vehicles are equipped with this protecting techniques.this protecting techniques.

► Most of the researches are going on in the Most of the researches are going on in the field of crush Initiators in order to determinefield of crush Initiators in order to determine

how many initiators are best.how many initiators are best.

► Even it can be applied to all the heavy Even it can be applied to all the heavy vehicles in future.vehicles in future.

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RESULT AND DISCUSSIONRESULT AND DISCUSSION As we have seen so far the front S-Rail As we have seen so far the front S-Rail

assembly of vehicle is used to absorb assembly of vehicle is used to absorb energy and maintain survival space for energy and maintain survival space for the occupants during a collision.the occupants during a collision.

The existing design of the S-Rail assembly The existing design of the S-Rail assembly makes it possible to absorb energy during makes it possible to absorb energy during a crash by bending. In our project, we a crash by bending. In our project, we have introduce CRUSH INITIATORS to the have introduce CRUSH INITIATORS to the front part of the existing s-rail assembly front part of the existing s-rail assembly design which absorbs energy in addition design which absorbs energy in addition to the energy absorbed by the bending to the energy absorbed by the bending action, due to the axial collapse.action, due to the axial collapse.

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The S-rail was first modeled in CATIA software. Then the CATIA model was imported to hyper mesh soft ware as an IGES file and was subjected to meshing. The meshed S-rail model was then exported to ABAQUS software where the solving and post-processing was done and the simulation was carried out.

From the study that we carried out and from the theoretical analysis we have come to conclusion that the energy absorbed during the collision by the front S-rail assembly with crush initiators is more than the energy absorbed by the front S-rail assembly without crush initiators

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REFERENCEREFERENCE► American Iron and Steel Institute “Vehicle Crashworthiness American Iron and Steel Institute “Vehicle Crashworthiness

and Occupant Protection”.and Occupant Protection”.► CADDAM Technologies “CATIA Training Guide”; Edition CADDAM Technologies “CATIA Training Guide”; Edition

2008 2008 ► Research Council for Automobile Repair “Vehicle Design Research Council for Automobile Repair “Vehicle Design

Features For Optimum Low Speed Impact Performance”; Features For Optimum Low Speed Impact Performance”; Edition, January 1995 Edition, January 1995 

► The Tracy Firm Attorneys At Law “vehicle Crashworthiness- The Tracy Firm Attorneys At Law “vehicle Crashworthiness- identifying If Vehicle Safety Defects Exists”. identifying If Vehicle Safety Defects Exists”.   

WEB ADDRESS:WEB ADDRESS:

www.autosteel.orgwww.autosteel.org

www.vehiclesafety.comwww.vehiclesafety.com

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