盒形件固体颗粒介质板材成形工艺研究

固体颗粒介质板材成形工艺是采用固体颗粒微珠代替刚性凸(凹)模(或弹性体、液体)的作用对板材拉深成形的新工艺。选用非金属固体颗粒介质——GM颗粒作为研究对象，以固体颗粒介质在高应力水平下的体积压缩试验和摩擦强度试验为基础，应用散体力学理论中扩展的Drucker-Prager线性模型构建固体颗粒介质有限元材料模型。以具有非轴对称性的方盒形件为代表，进行固体颗粒介质成形工艺的有限元模拟，研究成形过程中板材的流动特征和壁厚分布规律。工艺试验成功得到方盒形零件，将加载曲线、成形过程变形特征和壁厚分布曲线与数值模拟结果比对较为吻合。分析表明，采用以散体力学为基础建立的固体颗粒介质材料模型进行工艺模拟，能够得到与试验较为接近的变形特征和力能参数，可以应用于制定工艺方案的依据，为该技术在板材成形中的应用起到指导和借鉴作用。

Study on the Forming of Box-shaped Parts Based on Solid Granule Medium Forming

Solid granule medium forming(SGMF) is used for sheet metal deep drawing, where solid granule microsphere replaces the rigid punch or female die(or elastomer, liquid). Certain non-metallic granules(NMG) are selected as the research subjects. On the basis of the volume compression experiments and the ones of friction strength test, with both at a high stress level working on the solid particles medium, The finite element model of solid particles medium materials is constructed by the extended Drucker-Prager linear model in powder mechanics. The square box-shaped parts of non-axial symmetry is taken as an example, numerical analysis in respect of forming process of SGM is conducted; the flow characteristics of sheet and the wall thickness distribution law in the forming process are studied. Typical square box-shaped parts are successfully trial-produced. Loading curves, deformation characteristics in forming process and wall thickness distribution curves are proved in basic agreement with the result of finite element simulation. Studies show that the deformation characteristics and the force parameters, which is closed to the experiments can be generated from the numerical analysis on the SGM material model based on powder mechanic. At the same time, it can be the basis of the process plan which will in turn, play an important role in guiding the further application of the technique in sheet metal forming.