Application Of Chebyshev Interval Method In Crashworthiness Optimization Design Of Automobile Front Sturcture

Numerical optimization method is often used for deterministic optimization design in traditional research on Crashworthiness optimization design of automobile structure.However,the deterministic optimization results are often close to the constraint boundary,which leads to the unreliability of the deterministic optimization results when the design variables are affected by uncertain factors.Therefore,reliability design is particularly important in the vehicle design which takes into account crashworthiness and lightweight.Previous studies show that Chebyshev interval method plays an important role in improving the reliability of design solution.Therefore,the combination of Chebyshev interval method and traditional vehicle structure crashworthiness optimization method can improve the reliability of design solution,which has a certain engineering research value.In order to solve the problem that the design variables are uncertain in the vehicle crashworthiness optimization design,the Chebyshev interval analysis method is introduced into the traditional vehicle crashworthiness optimization design process,and the vehicle structure reliability optimization design method based on Chebyshev interval method is proposed.Finally,the method is applied to the optimization design of the crashworthiness of the front structure of the automobile to improve the reliability of the design solution.The main research contents are as follows:First,in order to save the calculation cost,this paper uses the design sample points to build the support vector regression model instead of the finite element model for calculation.In order to improve the fitting accuracy of the support vector machine regression model,the particle swarm optimization algorithm is used to optimize the kernel function parameters of the support vector regression model.The results show that the approximate model built in this paper meets the accuracy requirements,which is the reference for subsequent optimization It lays the foundation for the scientific design。Second,in order to verify the feasibility of Chebyshev reliability method in structural crashworthiness design,this paper carries out reliability design for the thickness of inner and outer panels of the front section of an automobile longitudinal beam.The thickness of the front inner and outer plates of the longitudinal beam is selected as the design variable,and the total energy absorption and total mass of the inner and outer plates are selected as the design objectives.The upper bound of the response interval is obtained by Chebyshev interval method for reliability optimization.The optimization results show that the reliability of the design solution is improved on the premise of ensuring the crashworthiness and lightweight objectives,and the Chebyshev reliability method can be applied to the research of vehicle crashworthiness optimization design.Third,in order to study the role of Chebyshev interval method in the crashworthiness design of vehicle structure,the vehicle finite element simulation model is built based on the frontal 40% movable barrier collision condition.The validity of the finite element model is verified by comparing with the real vehicle test.Four,in order to further improve the reliability of the vehicle structure crashworthiness optimization design solution,this paper optimizes the thickness of the key energy absorbing components at the front sturcture of the vehicle.Experimental design,approximate model and multi-objective optimization algorithm are used to solve the optimization problem.The results of deterministic optimization design improve the crashworthiness of the whole vehicle and reduce the weight of the structure,but the reliability of the constraint term is low.Chebyshev reliability method is used to solve the problem of unreliable deterministic results.The final optimization results show that the reliability of the whole vehicle is improved The crashworthiness and reliability of the vehicle realize the lightweight of the structure.The optimization design method of Vehicle Crashworthiness Based on Chebyshev polynomial has a certain engineering application value.