哪位有QUAD4的使用方法说明，或者下面的这个报告也可以：
Idriss, I.M., J. Lysmer, R. Hwang, and H.B. Seed, "QUAD-4 --A Computer Program for Evaluating the Seismic Response of Soil Structures by Variable Damping Finite Element Procedures," Earthquake Engineering Research Center, Report No. UCB/EERC-73/16, University of California, Berkeley, July 1973.
不胜感激。
