Analysis On Handling Stability And Optimal Design Of Suspension Hard-points For An Engineering Dump Truck

Engineering dump truck has the characteristics of heavy load,high center of gravity,driving traffic complex.With the development of urbanization,the pace of urban construction has been accelerated,engineering dump trucks have become more and more frequent in urban roads,and their driving safety issues have been widely concerned.Handling stability is one of the important properties that affect the active safety of the automobile.It is of great significance to improve the safety performance of the engineering dump truck by optimizing the design of the suspension hard-points to improve handling stability.In this paper,a domestic engineering dump truck is used as the research object.Using the multi-body dynamics method and virtual prototyping technology,ADAMS/Car is used as the platform to build vehicle rigid and flexible coupling multi-body dynamics model including the leaf spring front suspension model,the cab model,the steering system model,the balanced suspension model,flexible frame model,tire model,powertrain model and so on.The flexible body of the frame is generated by finite element method and verified by modal test.The front suspension leaf spring model is established by discrete beam method.According to the national standard,the simulation analysis of the handling stability including the steady static circular test,slalom test,returnability test and steering portability test are carried out,and the validity of the vehicle simulation model is verified by comparison with the road test.The result data are processed,and the handling stability performance of the vehicle is evaluated by scoring method.The influence of the suspension kinematic characteristics on the vehicle handling stability is introduced.The front suspension simulation test rig was established to simulate the kinematic characteristics by the parallel wheel jump test.Based on the structural characteristics of the leaf spring suspension,the reason of the poor performance of the toe angle and the caster angle is analyzed,and the primary selection of the hard points of the suspension is carried out.The four hard-point coordinates with large influencing factors were determined by the sensitivity analysis as the final optimization variables.The response surface method is used to fit the function relation between the optimization variable and the optimization target.The optimization result of the hard point coordinates is obtained by NSGA-? genetic algorithm.The simulation analysis and evaluation of vehicle handling stability before and after optimization of suspension hard points are carried out.The results show that the vehicle bank angle is reduced,the returnability is improved,the performance of the vehicle handling stability is more balanced,and the handling stability of the vehicle is improved on the whole.