【摘要】 <正> (一)前言在作结构的振动计算时,经常要考虑选用适当的特征值问题计算方法。最近研究肋形楼盖的振动,由于结构在平面的两个方向具有多跨连续的特点,以致频谱甚为密集,只求开头少数几个振型,不足以解决动力反应问题。为此曾选用豪斯霍尔德三对角化及带原点移动的 QL 法标准程序,这是目前计算完全特征系的最有效方法。但是随着自由度数目之增加,用 QL 法的计算时间愈来愈占主要地位。用 QL 法的计算时间大致与自由度数的更多还原

【Abstract】 In this Paper,a new method for evaluating the whole or a part of the eigensystem of a symmetrical tridiagonal matrix is developed.Using the modified main-coefficient sequence and the concept of“concentration-point”, the search of eigenvalues is easy and rapid.The modified main—coeffcient of concentration-point is continuous and nearly linear over the partitioned interval and a inter—extrapolation method which is 4～5 times faster then bisection method is adopted to locate the characteristic roots.After the eigenvalue is evaluated with appropriate accuracy,the eigen vector is easily determined by propagaton factors. It is well known that the QL method is a powerful one in evaluating the eigensystem of tridiagoal matrix.However,the method of propagation presented in this paper is more effective and rapid,especially for high order matrix and the ease where only a part of eigensystem is required. Computational programing,named“procedure PPGT”is prepared with ALGOL-60 language and it may be used immediately in computer progr- ams更多还原