Tube Cradle Type Of Impact Loads Virtual Design

Under the background of an Advance Research Project from the General Armament Department and a National Defense 973 Project, this paper is concerned with virtual design of cradle on the impact load during the firing of cannon by finite element dynamic method, experiment test, optimal design and visualization in scientific computing.Grid modeling method of finite elements with high precision for complicated structure is discussed. Skinning method is used for transition between solid and shell elements, which ensures the precision of modeling and enhances the efficiency of modeling. Transient impact load model acted on the cradle, equivalent model of equilibrator and constraint relation are investigated. To ensure the consistency and versatility of modeling, a general module for parametric modeling is developed.Based on the static stiffness and strength criterion, the stiffness and strength of cradle is analyzed in different conditions. The dynamic model of cradle is built, in which the nonlinearity of equilibrator is taken into consideration. By the method of numerical calculation, the dynamic stress and displacement of cradle subjected to impact load is obtained. A test bed for measuring dynamic strain of cradle is constructed, and the dynamic response of several key positions is tested. Tested result is analyzed and compared with that computed by FEM, which verifies the feasibility of virtual design.Aimed for lightweight of cradle, hybrid parametric modeling technology is investigated, and the mathematical optimization model and optimal environment are developed. In light of constraint condition of cradle stiffness and strength, cradle is partly optimized by multi-island genetic algorithm.Based on the OpenGL interface, reconstruction software for FEM data is developed. Grid model, hidden model and nephogram model are reconstructed from 3D data field under the software environment. The influence on nephogram display generated by different algorithms is discussed, which can be referable for visualization development of virtual design system.The preliminary findings of virtual design for the stiffness and strength of cradle achieved in this paper can be of certain reference to digital design of such mechanisms.