Size Optimization Of Triangle Track Wheel Under Multi-working Conditions Based On Ensemble Of Surrogate Model

Emergency rescue vehicles play an important role in emergency rescue and transportation.In the face of the complex and harsh environment in the rescue area and the timeliness of rescue,they are required to have good mobility and trafficability.The application of replaceable triangle track wheel effectively solves these two contradictory problems.However,the replaceable triangle track wheel itself has a large weight and how to meet the structural life requirements under a variety of working conditions still need further exploration.In this paper,the support frame of replaceable triangle track wheel is taken as the research object,and the size optimization is carried out under the condition of multiple working conditions,so as to make its fatigue life balanced under different working conditions and achieve the purpose of lightweight.The main work of this paper includes the following four aspects:(1)Based on the theory of multi rigid body dynamics and the software RecurDyn,the dynamic model of the vehicle equipped with replaceable triangle track wheel is built and its correctness is verified.Through this dynamic model,the dynamic simulation of the vehicle with changeable triangle track wheel under four typical working conditions is completed,and the load spectrum of the main load-bearing parts of the support frame is obtained.(2)Based on the linear cumulative damage theory and ncode software,the fatigue analysis of the brace under four working conditions is carried out.The main contents are: according to the structure,working condition and working environment of the support,the p-S-N curve of the material is modified;the fatigue analysis of the support under four working conditions is carried out;the platform for fatigue experiment design under multiple working conditions is built.(3)Based on the principle of surrogate model,workbench software is used to build the surrogate model for the quality of support frame with different sizes and the fatigue life of four working conditions.The main contents are as follows: the mathematical model of support optimization is determined according to the actual situation;the sample points of design variables and design objectives are obtained through experimental design;the evaluation method of composite surrogate model suitable for optimization is proposed and verified.(4)Based on the optimization theory and MATLAB software,the mathematical model of the support frame is optimized.The main contents are as follows: according to the actual optimization purpose and penalty function idea of the support frame,the mathematical model of dimension optimization of fatigue constraint is established;the method of transforming single objective multi constraint problem to multi-objective unconstrained problem suitable for heuristic algorithm is put forward;the optimization result is verified and analyzed.