抛物线壳体软模成形FEM-DEM耦合仿真研究

针对一些形状复杂、具有局部特征的难变形薄壁构件的成形问题,提出固体颗粒介质成形(Solid granules medium forming, SGMF)技术。并以薄壁的抛物线壳体零件为例,分析零件的特征及成形难点;基于ABAQUS平台,自行编制程序对抛物线壳体SGMF成形过程进行有限元法(Finite element method, FEM)和离散元法(Discrete element method, DEM)耦合仿真分析,探究不同摩擦因数对工件SGMF的影响。研究表明,FEM-DEM耦合分析技术兼顾离散颗粒介质与连续体板材各自的变形特点,能较准确模拟金属板材SGMF成形过程,并采用该耦合分析技术确定该抛物线壳体零件的最佳成形工艺参数;最后在模拟结果的基础上,开展抛物线壳体零件的颗粒介质成形试验研究,并成功试制出合格工件,试验结果与FEM-DEM耦合模拟结果基本吻合。

FEM-DEM Coupling Analysis and Experimental Research on Soft Forming of Parabolic Shell

In order to solve the forming difficulties of the thin-wall parts with complex shapes and local characteristics, the solid granular medium forming (SGMF) technology is proposed. The thin-wall parts of parabolic shell are taken as an example to analyze the characteristics and the points of forming difficulties. Based on the ABAQUS software, the SGMF forming process of the parabolic shell is analyzed by using the finite element method (FEM) and discrete element method (DEM) coupling by self-programming, and the influence of different friction factors on SGMF are investigated. The results show that the FEM-DEM coupling analysis technology have deformation characteristics with the discrete of granular medium and continuum sheet respectively, which can simulate the sheet forming process of the SMGF more accurately, and the optimum technological parameters of the parabolic shell parts are identified. Finally, based on the numerical results, the solid granules medium forming experiments of parabolic shell parts are carried out, the qualified parts are successfully produced, and the experiment results are in good agreement with the simulation of FEM-DEM model.