Fatigue Analysis And Optimization Of Vehicle Cab Under The Impact Wave Of A Certain Type Of Vehicle Gun

Truck-mounted howitzer intelligently combines the towed cannon with the vehicles,and has advantages of precision strike capability and tactical mobility.Design of truck-mounted howitzer centers on the integral thought of the cannon and the vehicles,it's very important to take the impact of the muzzle shock wave to the cab during launching into consideration,this will directly affect the layout and safety performance of the vehicle system.This paper carries out research based on these matters,a certain type of 155mm truck-mounted howitzer and its cab are set as the research objects,synthetically utilizing theory and analytical methods of computational fluid dynamics,transient dynamics,fatigue durability and car body structure optimization,et al,by using the finite element modeling and analysis software,the transient dynamic response and fatigue damage of the cab under the action of muzzle shock wave are obtained by numerical simulation,and put forward the optimization and improvement plan for the weak area of the structure.First of all,this paper introduces the muzzle flow phenomenon,muzzle shock wave is unsteady-state under expanded wave,emitted from the cannon equipped with muzzle brake,two different finite element models are built,which are in different working condition,then solving two models by applying computational fluid dynamics software,and the distribution of the shock wave overpressure on cab is get.The correctness of the model and the results are verified through comparing the data between numerical simulation and test.Build the finite element model of the cab according to its three-dimensional model,mean pressure data of the cab surfaces which are under monitored are extracted as loads,calculating the transient dynamic response of cab under the action of shock wave,and the area where are more seriously affected by the shock wave are found,then the calculating results are as input data for next step,applying fatigue analysis software to simulate the damage of the cab when it suffers for several times impact under the shock wave.According to the previous analysis results,multi-objective optimization and improvement schemes are proposed,and as an integral improvement,then the numerical calculation is carried out again,in order to verify the effectiveness of the improved scheme.The study of this paper has a strong guiding significance for the improvement of body design of the truck-mounted howitzer.