Discrete Element Method Analysis And Experimental Study For Bending Capacity Of Metal Skinned Sandwich Composite Panel

Today, when people faces in solving the analysis of structures that including the metal skinned sandwich panel, the most commonly methods are finite element method, boundary element method or finite difference method, however these numerical methods are based on the continuum mechanics,however these methods often hard to get the satisfactory results when they are used to solving large deformation and nonlinear problem. Therefore, seek to the new method for this kind of problem is very necessary.The discrete element method which previously widely used in geotechnical engineering had made great progress in recent years, it has gradually become a new method that can simulate the structural damage at present. This paper summarized the creation of discrete element method and it's theory and application development process, and introduced the current domestic and international research on the discrete element method, analyzed the discrete element method feasibility and of the metal skinned sandwich panel, and established reasonable discrete element model for metal skinned sandwich panel,which explored a new way to solve such problems.Through analyzing the basic principle of discrete element method, this paper put forward the suitable for metal skinned sandwich panel of discrete element method model. Through the analysis of various kinds of discrete element method PFC2D contact constitutive theory, this paper puts forward three contact model combination, and creating the three different contact combination of the metal skinned sandwich panel discrete element model, through the comparative analysis, when the sandwich core material and panel choose contact model respectively parallel bond model and contact bond model ,it can get satisfactory results. Through the analysis, the the parallel bond and contact bond parameters for two dimensional model and three dimensional model are confirmed . Then, this paper analyzes the affect of particle radius and friction factors to the results. Through the analysis on the convergence speed all parameters of the reasonable value, this article ultimately get the curve of the load and midspan deflection, through contrast with the results of experiment, finite element analysis and theoretical analysis , which shows that the model is reasonable. At last, the paper analyzed failure forms of four discrete element models with different span and thickness for the metal skinned sandwich panel in two dimensional and three dimensional cases, the results are consistent with the experiment and identical with theoretical analysis. The validation of discrete element method relative to the finite element method is proved through compare the damage form of the finite element simulation and the discrete element simulation.The study results of this paper suggest that it is rational to use the discrete element method to simulate the bearing capacity and failure modes of metal sandwich panels, and it can be used as a new attempt for this issues.