石端伟机械动力学用newmark_beta法进行动力学仿真，书本源程序没有包括0时刻的位移，该程序调用newmark函数，克服了书中缺陷。(Shi Du Wei's mechanical dynamics is simulated by newmark_beta method. The source program does not include 0 time displacement. The program calls Newmark function to overcome the de