In recent decades, vehicle safety becomes one of the most important issues in the vehicle industry. Hence, several organizations and institutions attempt to codify standards for analyzing vehicles strength in crash. These standards investigate the passenger’s safety through simulation of crash test and using crash test dummies. Due to high cost of experimental simulation, in the early stages of design and before manufacturing, safety evaluation is carried on by software simulation. In software simulation of crash test, behavior of vehicle structure in crashes is examined and if the vehicle is unsafe, its structure is then modified. This thesis aims to investigate and modify the body and the chassis of Iranian mini vehicle. This vehicle is in design stage and before prototyping and performing practical tests, its safety should be investigated by software simulation, according to standards. In this study, front chassis structure will be modified first and then optimized using thin wall energy absorbers. After completion of the model for Iranian mini vehicle, the frontal impact test on the structure of the vehicle is simulated according to standards of ECE-R 94 and USA FMVSS No. 208. These two standards are more comprehensive than other impact standards because they include items such as various vehicle's speed, impact barrier, gender of passengers and situation of seat belt. After modifying the body and chassis of the vehicle, detailed modeling of the vehicle will be performed in CATIA software. Then, simulation and finite element analysis will be carried on in HYPER WORK and LS DYNA software and strength of vehicle against impact and injuries of passengers' bodies will be studied. Finally, according to rating system of Insurance Institute for Highway Safety and based on injuries of passengers, Iranian mini vehicle is rated and its safety is evaluated by comparing the crash results with the results of other similar. Keywords: Vehicle safety standard, Vehicle crashworthiness, Vehicle passenger injuries, Chassis design, Thin walled structures, Energy absorption, Plastic deformation
