Research On The Protective Performance Of Bolted Car Body Under Explosive Impact Environmen

Bolt connection is a very common connection and fastening method for the body of protective vehicles.When the vehicle is impacted by explosion,the impact force generated by explosion will be transmitted to the interconnected body structure through bolts,and finally act on the passengers in the vehicle.In order to improve the protection effect of the vehicle to the passengers when facing the threat of explosion,it is necessary to reduce the impact force transmitted from the bolted connection to the passengers in the vehicle.Therefore,it is of great practical value and practical significance to study the protective performance of bolted body under explosion impact.In this paper,the bolted car body improved on the body of a special vehicle is taken as the research object.Aiming at the bottom explosion threat faced by the actual combat,based on the bench test of bolted structure and the actual explosion test of the original body,the anti-explosion protection performance of bolted car body is analyzed by the combination of test and simulation.Firstly,the formation process and description method of explosion shock wave are studied and analyzed,and S-ALE algorithm for simulating explosion shock process is obtained by introducing structured mesh.Through the theoretical formula calculation of plate and shell structure response under impact load and bench explosion test,it is verified that S-ALE algorithm is more efficient than traditional ale algorithm in dealing with explosion shock problem.It provides a more accurate and fast simulation algorithm for the later simulation of explosion impact process.Through the bench explosion test and simulation analysis of bolted structure,the dynamic response process of bolted structure under explosion impact is studied,and the influence of bolt diameter and spacing and the use of aluminum alloy materials on the anti-explosion performance of connecting steel plate is analyzed,which lays a theoretical foundation for the design of bolted structure of bolted car body.Then,Error Assessment of Response Time Histories and multi-objective optimization design theory are used to calibrate the flow field parameters of underbody explosion impact simulation.Finally,the bolted car body is put into the calibrated explosion shock environment for simulation analysis,and the bolted double floor structure is specifically designed.The results show that the improved bolted car body has better effect in the protection of passengers’ lower limbs,and after the optimal design of bolted double floor,the ability of the car body to protect passengers’ lower limbs is improved again.The research methods and results of this paper provide a certain theoretical basis and guiding significance for the design of bolted car body of protective vehicles.