在波浪响应分析中,广义模态力的前后步差异用作迭代计算的收敛准则判定。这种差异的默认值1%。在list文件中如下图所示‘RMS DIFFERENCE’ 为各个模态的前后步计算所得的模态广义力的均方根差异。在其之后还有一个‘TOTAL RMS DIFFERENCE’,这个值是对所有模态的综合考虑值,这个值也是迭代计算收敛的判定值。
**** MAXIMUM MODAL RESPONSES FOR ITERATION 0 ****
MODE RESPONSE TIME
CM SECS
1 -61.811 2.000
2 1.794 0.000
3 -0.057 2.000
** RMS DIFFERENCE FOR MODE 1 IS 4.643 PERCENT
** RMS DIFFERENCE FOR MODE 2 IS 4.422 PERCENT
** RMS DIFFERENCE FOR MODE 3 IS 3.490 PERCENT
ITERATION 1 *** TOTAL RMS DIFFERENCE = 4.313 PERCENT ALLOWABLE DIFFERENCE = 1.000 PERCENT