Explicit Dynamic Analysis of Automotive Bus Body Structure During Catastrophic Frontal Crash with Expulsion System
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This document presents an explicit dynamic analysis of automotive bus body structures during catastrophic frontal crashes, emphasizing the significance of driver and crew safety due to high injury risks in such incidents. It discusses the lack of international regulations to protect bus drivers in collisions and suggests potential solutions, including improvements to energy absorption capacity in bus designs. The research employs finite element analysis (FEA) to identify structural weaknesses and proposes enhancements to crashworthiness and overall vehicle performance.
Explicit Dynamic Analysis of Automotive Bus Body Structure During Catastrophic Frontal Crash with Expulsion System
- 1. Explicit Dynamic Analysis of Automotive Bus Body Structure During Catastrophic Frontal Crash with Expulsion System Carried out by : Davalsab.M.L M.Tech (Machine Design & Dynamics) R15MDD10 School of Mechanical Engineering, REVA University , Bangalore Daval.techno@gmail.com / 8904567449
- 2. Importance of Research According to the Accidents investigation for buses and Automotive, Accidents involving frontal crash creates a vital portion among all bus accidents. Through this sort accidents, front body of the bus structure gets severely damages and this puts the drivers and crew in more injury risk. And most of the frontal crash accidents ends up in the death of the driver, as a result of this, the protection of each the driver and also the crew ought to be ensured within the case of frontal crash accidents. To providing the driver safety is crucial since bus driver is that the key person for keeping the control of the bus within the event of accidents in order to that safety of the passengers are going to be ensured. Nowadays there is no international regulation providing any protection for the bus drivers in case of frontal collisions. Based on the technical analysis of real bus head on impacts this paper tries to collect the major issues which may help to develop international regulations in this subject.
- 3. Accident Statistics ACCIDENT ANALYSIS AND STATISTICS The most frequent accident of buses is the frontal collision (head on impact) Many statistics have been already published in this subject, which prove that the rate of the frontal collision is 50-60% related to the total number of accidents. It is very difficult to compare the different statistics, because the basis of their collection and evaluation is different. Some of them considers only those accidents, in which: the rollover, which is rather rear (2-6%) but it has a very high rate of fatality (and injury) the frontal collision which happens very often, therefore the total number of fatalities and injuries is high.
- 4. Literature Survey Dr MATOLCSY, Mátyás (1) PROTECTION OF BUS DRIVERS IN FRONTAL COLLISIONS, The paper refers to a practical solution, which can help to protect the driver: the principle of the safety platform. A rigid (in its plane) platform is used in the DC with a soft, deformable connection to the frame of the DC. The driver seat, the steering column is fixed to this platform. Muhammad E. Cerit,(2) Mehmet A. Guler,(2) berter, Ugur Elumen(2) Improvement of the Energy Absorption Capacity of an Intercity Coach for Frontal Crash Accidents (2) ECBOS – Enhanced Coach and Bus Occupant Safety(3), Based on the background of the European Vehicle Passive Safety Network a consortium of 7 European Research Institutes and Universities was formed to investigate the field of current bus and coach accidents as well as to propose new cost effective test methods and suggestions for improved regulations to decreas the injury risk for the bus occupants. A.HariKumar(4), V.Deepanjali,(4) Design & Analysis of Autombile Chassis. Eicher E2 TATA Truck ladder chassis with the constraints of maximum shear stress, equivalent stress and deflection of the chassis under maximum load condition. In present the Ladder chassis which are uses for making buses and trucks are C and I cross section type, which are made of Steel alloy (Austenitic Manjinder Singh Sidhu (5)A Crash Test is a form of destructive testing usually performed to ensure safe design standards in crashworthiness and crash compatibility for various modes of transportation or related systems & components. Frontal crash/impact tests are usually impact upon on a solid concrete wall at a specific speed, but also can be vehicle- vehicle impact.
- 5. Case 1 Case 2 Case 3 Case 4 Case 5 Case 6
- 7. FEA model FEA results Discretization Numerical solver FEA Pre- processing FEA Solution FEA Post- processing MATHEMATICAL MODEL
- 8. Explicit Dynamic Analysis What is Explicit Dynamic Analysis ? Explicit uses explicit time integration to solve the equations of motion. It solves short-duration problems with complex material response yet makes it easy to set up a problem with minimum input and effort. Explicit easily handles the response of materials from impacts, high pressures, and other forms of loading that result in deformation, failure and fragmentation In nonlinear implicit analysis, solution of each step requires a series of trial solutions (iterations) to establish equilibrium within a certain tolerance. In explicit analysis, no iteration is required as the nodal accelerations are solved directly.
- 9. Pendulum Test Pendulum Test Facility, designed and built to Society of Automotive Engineers (SAE) standards, and cost-effective testing techniques. The pendulum is used to simulate impact forces generated by a vehicle involved in a frontal collision, and is regularly used to test components According to The resolution 316/09 of the Brazilian National Transit Council (CONTRAN, 2009) demands that after two pendulum tests are carried out, no bus part of the structure tested could present permanent longitudinal strain higher than 200 mm. The Fig illustrates the execution of the pendulum test. An impact mass of 1010 kg with a pendulum spin radius of 4.75 m impact against the front of the bus structure. In the case presented in the figure permanent displacement in the bus frontal part was 123.2 mm.
- 10. Research on Frontal Crash Test
- 11. • The bus structure was crashed with a pendulum having a mass of 1500 kg • The Overall Finite element Model consists of 4,67,999 – 5,67,248 shell elements, • Each mesh size chosen to be 10mm to 3 mm Improvement of the Energy Absorption Capacity of an Intercity Coach for Frontal Crash Accidents (1) Fig 2 & 4
- 13. Benefits Summary After studying the results and the stress pattern on the bus, benefits of Frontal Crash Analysis using FEA analysis in ANSYS/ Hypermesh are as under:- 1. Critical/Weak members are strengthened to increase the strength of structure. 2. Safety of the Driver/Co-Driver/Passengers. 3. Time saving. 4. Cost saving. 5. Reduction in number testing vehicle. 6. Design change suggestion to design team as per analysis report. Challenges 1. Selection of appropriate element type, size and control cards for element properties for getting accurate results. 2. How to correct Initial penetration in contact interfaces. 3. Calculation of the total time of impact simulation to ensure appropriate stabilization of Global variables (Internal and Kinetic energy).
- 14. Future Plans We can further extend Crashworthiness (FEA) study & use of ANSYS Software for Vehicle Weight Reduction/Optimization to improve the overall performance of the Bus. Also perform Frontal Impact of Bus/Truck using AIS-029. Suppositions The Frontal Crash Simulation proved to be an effective method to validate the Structural Crashworthiness. The software gave the freedom to study and analyze the output in different forms which are difficult to workout practically. Good co-relation is build b/w BASE LINE DESIGN & ACCIDENTAL VEHICLE. Critical/Weak members are strengthened to increase the strength of structure. An absolutely contemporary CAE Driven Design approach was implemented to arrive at the best possible design solutions.
- 15. 1. Dr MATOLCSY, Mátyás Scientific Society of Mechanical Engineers (GTE) Budapest, Hungary 2. March 2008, Muhammad E. Cerit, Mehmet A. Guler, berter, Ugur Elumen. Department of Mechanical Engineering University of Economics and Technology, Ankara , Turkey 3. January 1st 2000 European Commission 5th Framework COMPETITIVE AND SUSTAINABLE GROWTH, Enhanced Coach and Bus Occupant. 4. A.HariKumar(4), V.Deepanjali,(4) Design & Analysis of Autombile Chassis. International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 5, Issue 1, January 2016 5. Manjinder Singh Sidhu, Frontal Crash of Bus, Altair technology Conference 2013 6. Agenor Dias de Meira Jr.a , Ignacio Iturriozb , Márcio Walbera , Fábio Goedel Numerical Analysis of an Intercity Bus Structure: A Simple Unifilar Model Proposal to Assess Frontal and Semifrontal Crash Scenarios Refrence :