Crash Analysis of Front under Run Protection Device using Finite Element Analysis

Abstract

Under-running of passenger vehicles is one of the important parameters to be considered during design and development of truck chassis. Front Under-run Protection Device (FUPD) plays an important role in avoiding under-running of vehicles from front side of a truck. An explicit finite element software Altair Radio's is used in FUPD analysis for impact loading. The deformation of FUPD bar and plastic strains in FUPD components are determined in the impact analysis for predicting failure of the system to meet the compliance requirements as per IS 14812-2005. Additionally, failure analysis of the FUPD attachment points with chassis is determined. Physical testing can be reduced significantly with this approach which ultimately reduces the total cycle time as well as the cost involved in product development. I. INTRODUCTION In head-on collisions of bonnet-type cars (sedans, wagons, hatchbacks, etc., here after referred to simply as cars) and heavy trucks, the car often under runs the front of the truck, and the car crew received the serious or fatal injuries. The crash safety performance of the car depends on the way its structural parts interact with the structural parts of the truck. FUPD equipment that prevents the car from under running the truck is obligatory in India. The required strength and ground clearance of FUPDs are specified in the relevant regulations used in India. Accidents between cars and trucks are among the most fatal accidents because of the car under running. This phenomenon leads to serious and fatal injuries for car occupants because of intrusion of the car structure into the passenger compartment. This has led to the development of test procedure for energy-absorbing front under run protection systems for trucks. There is a summary of accident analysis of several European countries, where we can read that of the 48000 fatally injured people in road traffic accidents in 1992, 13000 people were killed in accident with trucks involved, about 7000 were car occupants and 4200 of them were killed in car-to-truck frontal collisions. It is very common incident that during the accident a passenger vehicle going under the heavy commercial vehicle either from rear, front or side. During collision, there is a risk that the passenger vehicle will penetrate under (run under) the front or rear part of the truck and thus there are great chances of fatal injuries to the occupants of the passenger car. The design and the strength of the Front Under-run Protection Device (FUPD) should be such that it should take the impact load and avoid the under running of the passenger vehicle from the front of the heavy commercial vehicle. Physical testing is done with 5 impactors with specific load and sequence; hit the FUPD to evaluate its strength. This scenario is replicated using Finite Element (FE) solvers like Altair Radio's. The load taken by the FUPD is evaluated using reaction forces. This virtual validation is important for cost saving in the tooling, repetitive testing of the vehicle and cost involved in the same. The Government of India felt the need for a permanent agency to expedite the publication of standards and development of test facilities in parallel when the work on the preparation of the standards is going on, as the development of improved safety critical parts can be undertaken only after the publication of the standard and commissioning of test facilities. To this end, the Ministry of Surface Transport (MOST) has constituted a permanent Automotive Industry Standards Committee (AISC) vide order No.RT-11028/11/97-MVL dated September 15, 1997. The standards prepared by AISC will be approved by the permanent CMVR Technical Standing Committee (CTSC). After approval, the Automotive Research Association of India, (ARAI), Pune, being the Secretariat of the AIS Committee, has published this standard. For better dissemination of this information ARAI may publish this document on their web site. In Indian vehicles FUPD, still it is not implemented. By this analysis will know that how it can reduce passenger life while impacting to car, pole..Etc. FUPD is designed with the help of European standard dimensions and then will apply the initial velocity from front side and check the strength of the FUPD, if it safe then this thesis is successfully projected. It's a trial and error process. The strategy in selecting a test procedure is to identify tests that have the potential to improve the crash protection provided across a broad range of real-world impact conditions. The crash test conditions, e.g., impact