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离散介质填充的中空薄壁型材常常作为整体结构用于一些特殊场合,如某些材料成型过程或建筑构件。这类复合结构的变形涉及致密金属的弹塑性耦合变形、松散颗粒压实以及管壁与填充物之间的相互作用。为认识其复杂力学行为,研究了填充不同粒度和材质的两种颗粒的Al 6061管正挤压过程。对圆管坯内腔体积变化的分析表明,随着正挤压时外径缩小,内腔容积通常减小,从而给填充物带来三轴压力并导致其致密化。填充使得挤压载荷增加;由于细粉和钢丸具有不同迁移与重排方式,二者的挤压力-行程曲线呈现不同形态。此外,较小的管材r值(Lankford值)使得填充介质静水压力增加并提高其致密化程度。
Hollow thin-walled sections filled with discrete media are often used as monolithic structures for special applications such as certain material forming processes or building components. Deformation of such composite structures involves elastic-plastic coupling deformation of dense metal, compaction of loose particles, and interaction between the wall of the tube and the filler. In order to understand its complex mechanical behavior, the Al 6061 tube was extruded with two kinds of particles of different particle sizes and materials. Analysis of the change in the volume of the circular tube blank lumen shows that as the outer diameter decreases during normal extrusion, the lumen volume generally decreases, giving the packing triaxial pressure and densification. The filling makes the extrusion load increase. Because of the different migration and rearrangement of the fine powder and steel shot, the extrusion-stroke curves of the two show different shapes. In addition, the smaller tube r value (Lankford value) allows the filling medium hydrostatic pressure increase and increase its degree of densification.