Punch press: machine tool that changes the size or shape of a piece of material usually sheet metal by applying pressure to a die in which the workpiece is held.
冲床：将压力加到装有工件的模具上，以改变一片材料，通常是金属片的大小和形状的机床。
2
Contact problem of compound material plane with cracks under a rigid punch action is studied in the third chapter.
第三章研究了具任意形状裂纹复合材料平面在单压头作用下的接触问题。
3
Contact problem of compound material plane with periodic cracks under periodic rigid punch action is studied in the fourth chapter.