Supposing the hammering load action on the top of the pile is periodical, the hammering pro-cess is simplified as a parameter stimulating vibration problem.
假设桩顶的锤击荷载是周期变化的，打桩过程简化为一个参数激振问题，归结为求解Mathieu方程的稳定界限,对于多层硬粘土、砂土与软粘土以及混合分层的情况，导出了桩的临界稳定长度,并得到了一组显式表达式。
The punch load of nickel plated steel strip and steel strip was compared,and the surface morphology of inside wall of circular cups with different stamping depths was analyzed.
在RG2000型微机控制电子万能试验机上对镀镍钢带进行冲压成型试验,研究了镀镍钢带在不同压边力作用下的成型性能,对比了镀镍钢带与未镀镍钢带在冲压成型中所需的冲头载荷,对不同冲压深度杯形件侧壁内表面形貌变化做了比较研究。