IRJET- Study of Non-Linear FE Vehicle Model using Multiple Impact Simulation

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 06 | June 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 3411
Study of Non-Linear FE Vehicle Model using Multiple Impact Simulation
Nehal Kulkarni1, Prof. S.S. Chappar2
1PG student, Department of Mechanical Engineering, BLDEA’s V P Dr. P G H CET VIJAYAPURA, KARNATAKA, INDIA.
2Professor, Department of Mechanical Engineering, BLDEA’s V P Dr. P G H CET VIJAYAPURA, KARNATAKA, INDIA.
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Abstract: The simulation of vehicle crashes by using
computer software has become an indispensable tool for
shortening automobile development time and lowering costs.
It also has huge impact on the crashworthiness of an
automobile. Automobile CAE Software is mainlyusedtoassess
the performance quality of vehicles. As the automobile is a
product of technology -intensivecomplexity, itsdesignanalysis
involves a broad range of CAE simulation technique. An
integrate CAE solution of automobiles can include comfort
analysis (vibration and noise analysis), safety analysis (car
body collision analysis), process-cycle analysis, structural
analysis, fatigue analysis, fluiddynamicsanalysis, testanalysis,
material data information system andsystem integration. The
objective of this work is to simulate aA-pillar, B-pillar, ofcrash
of an automobile vehicle and validate the results. The aim is
also to alter some of the materials of the components with a
view to reduce the forces experienced during the crash.
Computer models were used to test thecrashcharacteristicsof
the vehicle in the crash. The software used for the simulation
will be LS-DYNA. It is widely used by the automotive industry
to analyze vehicle designs. It accurately predicts a car's
behavior in a collision.
Keywords: Crashworthiness, LS-dyna, A & B Pillars, CATIA,
Load curves, Deflections and Von Misses stresses.
1.INTRODUCTION
First ever accident in the field of automotive sector has took
place in the city of New York in 1889.This situation raised
the birth of automobile protection as one of the research
areas of interest. From past three decades, occupant
protection is considered as the important design criteria
among all the functional performance for motor
transportation on ground. Industry people understood the
need in the beginning stage to carry out protection of motor
passenger before everyone thought about automobile plays
vital role for means of transportation.
In year 1934 General Motors conducted first ever motor-to-
object frontal crash test, lapping the motor into a still wall.
These first tests were considered most important in today
standards.
1.1 INTRODUCTION TO A-PILLAR:
Pillars nothing but thevertical ormarginal vertical structural
supports of a motor body area named respectively by the
names A, B, C and D pillar (in large car) checking from all the
structural parts front to back. Better understanding in the
car’s pillars is understood by alphabetical designationwhich
gives us common platform for design and vital
communication.
An ideal A-pillar is one that is light and slim and remains
folded during normal operationbut expandbyhigh-pressure
gas in a crash, resulting in a significant increase in cross-
section, strength and high crush resistance. These
contradictory requirements can becombined withinA-pillar
for bloomed cross-section. Like common driving, the cross-
sectional area of specimen considered is folded form, which
helps in providing good visibility for driver. First in theform
of crash, the A-pillar blooms, which gives a vital raise in
cross-sectional area, and the higher cross-sectional area
raises the A-pillar strength. Additional strength of the A-
pillar can be obtained by maintainingthepressureinsidethe
A-pillar during loading. Expandable A-pillars may be
accomplished in folding its body structure, and when
needed, expanding the structure by giving rise to a higher
internal pressure. A cost cum weight and efficiency way for
generating overpressurewasinusingpyrotechnical inflators
(gas generators).
1.2 B-PILLAR
The B-pillars are considered as important load supporting
elements for any of automotive framework. Itworksasmain
force carrying structure in motor vehicle roof. It is featured
with seam-welded structure, thin-walled structure, closed-
sectioned structure produced from higher strengthening
steel materials. B-pillars are the important pillars on either
side of a motor vehicle i.e., it must be whole or part
assembly, here transverse horizontal planes pass thorough
in seating arrangement points in form driver belt seat. B-
Pillars will be the pillars provides on either side in motor
vehicle between the back to front windows. B-Pillars
mounted in motor vehicle will latch for front door and
providing hinge supports for the back door will be steel
made structures welded on firm base consideringoneend to
rocking panel plate and pan floor with the bottom side of
motor vehicle while others side to those upper rail for
robustness and supporting with upper panel. Because of the
many important requirements in satisfying optimal criteria
against crush making of upper panel, B-pillars have become
a vital part of car motors designs. Therefore, become a vital
aspect in engineering design making in present day motor
cars. Its need in passenger protection makes B-pillars as
important structure in crashworthiness for motor vehicle
beside sudden crash. However, this escalates the different
mixing nature in B-pillars conceptual designswithrespectto
very high sudden crash resistance against never predicted

side accidents of motor vehicles. The positional structures of
B-pillars in motor vehicle considersitverymuchimportance
in the provisions of high sudden crash resistance and safety
to motor vehicle passengers in sudden crash programmers
that involves sudden side impacts. The highest stress given
by higher sudden crash structural members (like B-Pillars)
after displacement is of much importance, as it can help in
predicting whether the specimenhasoveresteemeditsyield
criteria or not. These types are likely achieved by
considering side pole side sudden crash test (known as
Advanced Euro Mobile Deformable Barrier-AEMDB) or
computerized test. However, reinforcing and strength
forming structures and its members are most advantageous
as compared to substitution with new are again designed
members as insufficient resistance for external loading will
be achieved.
Fig 1.2 Typical frame of car with B-pillars
1.3 Crashworthiness:
It is the ability of a structure to protect its occupants during
an impact. This is commonly tested when investigating the
safety of vehicles. Depending on thenatureoftheimpactand
the vehicle involved, different criteria are used to determine
the crashworthiness of the structure. Crashworthiness may
be assessed either prospectively, using computer models
(e.g., LS-DYNA, PAM-CRASH) or experiments, or
retrospectively by analyzing crash outcomes.
Crash test is a form of destructive testing usually performed
in order to ensure safe design standards
in crashworthiness and crash compatibility for various
modes of transportationor relatedsystemsandcomponents.
Frontal-sudden crash tests: is the one which all or most of
people initially think when thinks for a vehicular crash
analysis. Motor Vehicles usually subjected sudden crash for
solid objects or concrete walls with pre-defined speed, but
there are also be vehicular impacting vehicle crash.
Roll-over analysis: is one type of tests where vehicular
ability (especially the pillars attachedtoroofs)insupporting
itself for dynamic conditions. much recently, dynamic
rollover analysis was proposed in line with static crush
analysis.
Automotive safety: reduction in the relative velocities
between the passengers and the vehicular interiors to
reduce risking of injuries to thepassengersduringaccidents.
Fig 1.3 Typical supporting pillars and their location
2. RESEARCH METHODOLOGY
The finite element (FE) method is employed to conduct the
study for this project work. The software used is LS-DYNA.
LS-DYNA is predominant software in the field of FEA. This
project needs nonlinear large deflection analysis, for which
LS-DYNA solver is known to yield accurate results.
2.1 MATERIAL PROPERTIES
In many of the FEA software it is possible to use multiple
materials within the structure like Isotropic (in which
material property remains same throughout), Orthotropic
and An-isotropic materials.Theabovelayeredmodel created
was imported to LS-DYNA workbench through IGESorSTEP
file and the material model is created using the standard
vehicle engine data. The Material properties considered for
the Present study are the present industrial Properties and
this study gives the need of the hour. The investigation of
linear and nonlinear performance was done with materials,
like Steel. The material properties used in the analysis are
tabulated as Table 2.1
SL.NO NAME
THICK
NESS
YOUNGS
MODULUS
(E)
DENSITY
(ρ)
1. A pillar 1.4 210000 5.89E-09
2. A pillar 2 210000 6.29E-09
3.
upper a pillar
trim
2.8 1100 2.20E-09
4.
up a pillar trim
rein for
0.9 217000 4.48E-09
5. door 1.4 211000 7.89E-09
6. door window sill 1.4 216100 7.89E-09
7. door up reinforce 0.51 214800 4.48E-09
8.
win sill
reinforcement
0.86 215000 7.89E-09

9.
windshield - Top
Layer
2 78000 4.48E-09
10.
Door.L_inner_Tail
orweld-blank
1.4 210000 5.36E-09
11.
windshield-
Bottom
2 74000 4.48E-09
12.
windshield-
midlayer
0.8 550 4.48E-09
13.
left front door –
window
4 73000 1.20E-09
Table 2.1:Industrial Propertis of the Pillars
3. LS-DYNA Nonlinear Analysis
The methodology adopted for conductingnonlinearanalysis
of 13layered A-pillar and B-pillar Materials. Details of the
project are given as below.
3.1 Modeling of A-pillar
We require solid model of A-pillar of vehicle to build FE
model. here we have taken real engine for our study first we
got the dimensions of real engine which is retrieved by CMM
machine, using those dimensions we modeled A-pillar in
modelingsoftware called CATIAV5.Andthoseareassembled
in assembly work bench of CATIA modeling software. Fig.
below shows the CAD Model of the A-pillar. The
representative model layered shells were modeled inCATIA
V5. A stacking sequence was used for modeling layered
structure of steel shells.
 Creating part (solid) modeling of each part
& Assembling.
 Converting solid model into IGES format.
Fig 3.1 Compact view the CAD model of the A-pillar
Full detailed view of A-pillar imported on to LS-DYNA is
shown with color contours.
Fig. 3.1.1 CAD Model in LS-DYNA
3.2 Meshing of A-pillar
The meshing of the A-pillar structure is carried out by
considering SHELL281which has the special advantages list
of advantages of SHELL 281 are as below,
 It is a 4-node element with six degree of freedom at
each node.
 It facilitates modeling of layered steel structures.
 It has elasticity, plasticity, stress stiffening, large
strain and deflection, and nonlinear Stabilization
features suitable for nonlinear analysisofthinsteel.
 It is best suitable for layered and structured shells.
 It is suitable for linear and non-linear thin to
moderately thick shells.
Therefore, steel metal and thin steel were meshed with
SHELL 281 elements.
Fig. 3.2 Meshed FE Model of A-pillar
3.3 Modeling of B-pillar
Modeling of the A-pillars and B-pillars were carried out by
taking account of commercial software’s like CATIA V5.
Fig. below shows the CAD Model of the B-pillar.

Fig. 3.3.1 Compact view the CAD model of the B-pillar
Full detailed view of B-pillar imported on to LS-DYNA is
shown with color contours.
Fig. 3.3.2 CAD Model in LS-DYNA
3.4 Meshing of B-pillar
The meshing of the B-pillar structures is also carried out by
considering SHELL 281, the model was meshed usingsweep
mesh technique, which holds good for axisymmetric bodies.
The parameters which signify the quality of the mesh such
as, aspect ratio, warpage, skew angle, Jacobean, minimum
and maximum angle were satisfied. A layered element was
necessary to model the composite structures, hence
SHELL281 quadratic element was used.
Fig 3.4 Meshed FE Model of B-pillar
3.5 Loading and boundary conditions
In this stage for defining boundary conditions LS-DYNA to
best simulate the experimental testing conditions, the
models were constrained in both the ends respectively.
Detailed fig. is shown below,
Fig 3.4 Detailed view of A & B pillar
4. FEA RESULTS AND DISCUSSIONS
The below fig shows the imported 3D A-pillar of vehicle.The
various stress & deformation contours on the A-pillar and
stress and directional deformation (along the x-axis) for a
velocity of 29kmh are represented below, which is
considered as standard speed for the assessment of
crashworthiness according to NCAP (New Car Assessment
Program) for the HIC (Head Injury Criteria) for the person
driving the vehicle. This speed will indicate the minimum
amount of injury that person can undergo during the crash
analysis.
Fig.4.1 Displacement contour of a pillar

Fig.4.1.1 Stress counters of A-pillar
It is observed for the A-pillar maximum displacement is
observed in the vicinity side point as shown in the Fig 4.1
and the maximum displacement is observed to be
24.15mmThe maximum stress is observed to be 6.28e-
2GPaand it is clear from the Fig 4.1.1 that maximum
deformation is observed corresponding to maximum stress
region.
The below fig. shows the imported 3D B-pillarofvehicle.The
various stress & deformation contours on the A-pillar and
stress and directional deformation (along the x-axis) for a
velocity of 35kmh are represented below,
Fig.4.1.2 Displacement contour of B- Pillar
Fig.4.1.3 Stress contours of B- Pillar
It is observed for the B-pillar maximum displacement is
observed in the vicinity side point as shown in the Fig 4.1.2
and the maximum displacement is observed to be 50.61mm.
The maximum stress is observed to be8.53GPa anditisclear
from the Fig 4.1.2 that maximum deformation is observed
corresponding to maximum stress region.
From the above study it is clear that the occupant sitting
inside the vehicle will have serious injury because of the B-
pillar, rather than the A-pillar, as the study shows the
displacement of B-pillar is higher compared to the
displacement of A-pillar and even the stressinducedarealso
higher so this comparative study will definitely give us clue
understand the vehicle crashworthinessforthesidecrashes.
5. CONCLUSIONS
The conclusions derived based on the FEA numerical
analyses on A & B-pillars are presented as follows.
 LS-DYNA FE Analysis overestimated the other
commercial software packages under NCAP (New Car
Assessment Program) test. Hence a nonlinear buckling
analysis is mandatory.
 LS-DYNA Non-linear analysis predictstherealisticvalue
as compared to other tests.
 The performance in the dummies (occupant) which are
verified at a greater impact speeds of 35mph. Enhances
injury criteria under NCAP.
 This vehicle crashworthiness evaluation under side
impact gives us real picture of amount of injury in head
of person sitting inside the vehicle.
The goal of crashworthiness is an optimized vehicle
structure that can absorb the crash energy by controlled
vehicle deformations while maintaining adequate space so
that the residual crash energy can be managed by the
restraint systems to minimize crash loads transfer to the
vehicle occupants.

REFERENCES
[1] TejasagarAmbati, ‘SIMULATION OF VEHICULAR
FRONTAL CRASH-TEST’, SAE International, 2007-01-
1245, 2017.
[2] P. Satope. I. B. Owunnat, Design optimization of a B-
pillar for crashworthiness ofvehiclesideimpact.Journal
of Mechanical Engineering and Sciences, Volume 11,
Issue 2, pp. 2693-2710, June 2017.
[3] Shaik K b, OPTIMIZATION OF A AND B PILLARS OF
AUTOMOBILE FOR CRASH WORTHINESS- Journal of
Advanced Research in Dynamical and Control Systems,
Vol. 9. Sp– 14 / 2017.
[4] Jian LIU and Tao SUN “Numerical Simulation of Car
Crash Analysis Based on Distributed Computational
Environment ProcInstnMechEngrs (IMECHE) Part
K.2004, pp 107-117.
[5] Byeong Sam Kim, ‘FINITE ELEEMNT FRONTAL CRASH
ANALYSIS OF NEV VEHICLE’S PLATFORM WITHUPPER
AND SUB FRAME BODY’, journal Iternational,2005-26-
046, 2009.
[6] BerukHailu, ‘A New Accident ProofMaterial DesignforB
- Pillar of A Car’ International Journal of ChemTech
Research, Vol.11 No.07, pp 01-11, 2018.
[7] AniekanEssienubongIkpe, Design and Reinforcementof
a B-Pillar for Occupants Safety in Conventional Vehicle
Applications, International Journal of Mathematical,
Engineering and ManagementSciences,Vol.2,No.1,37–
52, 2017.
[8] Dongming Sun, Lightweight Study of Carbon Fiber
Composite B-Pillar Based on Equal Stiffness Principle-
Open Access Library Journal, 2018, Volume 5, e4822.
[9] BengtPipkorn, Improved car occupant safety by
expandable Apillars. International Journal of
Crashworthiness, ISSN: 1358-8265.
[10] M.M.Kamal, “Analysis and Simulation of Vehicle to
Barrier Impact,” SAE Paper No. 700414.
[11] C.L.Magee - Keynote Address, “Design for Crash Energy
Management - Present and Future Developments,” The
Seventh International Conference on Vehicle Structural
Mechanics.
[12] Wierzbicki, T,. and W. Abramowicz, “Stability of
Progressive Collapse,” Manual of Crashworthiness
Engineering, Vol. III, Center For Transportation Studies,
Massachusetts Institute of Technology.
[13] L.M.Patric, “Human Tolerance to Impact and Its
Application to Safety Design,” Biomechanics and Its
Application to Automotive Design, SAE Publication P-49
AUTHOR PROFILE
NEHAL ASHOK KULKARNI
Obtained his Bachelor’s degree in
mechanical Engineering from
Visvesvaraya Technological
University (VTU). He is presently
pursuing Master Degree in
Mechanical Machine Design from
VTU.

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