摘要:
分析了N.M.Newmark和E.L.Wilson等按位移作变量逐步积分法的主要特点.提出以速度为变量求解动力学问题的速度元法.针对无阻尼系统,构造了一种简化格式,讨论了稳定性.由于该格式在无阻尼和拟静力阻尼情况下为显式,每个时刻,不求解代数方程组,其计算量与Newmark等方法比较,显著减少.对非线性动态问题,该计算格式可作为取得较好迭代初值的一个办法.文中,就任意阻尼系统,列出了速度元法的推广形式.相应非线性情况,提供了速度增量迭代格式并证明了收敛性.文末,附录了典型问题的数值检验结果.
Abstract:
After analysing the essential features of successive integration method taking displacement as variable by N. M. Newmark and E. L. Wilson et al, this paper presents a "Velocity" Element Method, taking velocity as variable for the solution of the initial value problem.A simplified scheme is offered for the non-damping system, and the stability is also discussed. Owing to the fact that this simplified scheme for non-damping and apparent static damping is explicit in form, it is unnecessary to solve the algebraic system of equations at every time interval, consequently the amount of computation is greatly reduced. For non-linear dynamic problems, this scheme may be used to obtain fairly good initial values for iteration.An extended form of "elocity" Element is presented for the arbitrary damping system. For the non-linear cases, the incremental Velocity iteration scheme is adopted and its convergence proved. Some discussions have been given on artificial damping and the effect of the parameter.Finally, the results of numerical calculatio of some typical problem are given in the appendix.