振动与冲击
振動與遲擊
진동여충격
JOURNAL OF VIBRATION AND SHOCK
2015年
8期
12-19
,共8页
附加振型%虚拟激励法%绝对位移直接求解%振型分解%误差分析
附加振型%虛擬激勵法%絕對位移直接求解%振型分解%誤差分析
부가진형%허의격려법%절대위이직접구해%진형분해%오차분석
additional modes%pseudo excitation method%directly solving absolute displacement%mode decomposition%error analysis
为提高已有绝对位移直接求解虚拟激励法的求解效率及精度,对结构支座节点附加大质量块并释放支座约束,采用基于附加振型的振型分解法进行求解,附加振型来源于附加大质量块。对附加振型、常规振型的振型特性和振型贡献及计算效率进行了理论分析,分析表明:通过构建少量附加振型就可精确捕获结构拟静位移,且只需采用与相对运动法同等数量的常规振型就可精确捕获结构动态相对位移,与Wilson位移输入模式的绝对位移振型分解法相比,在保证计算精度的条件下可大大减少绝对位移求解所需的振型数。此外,对附加振型绝对位移求解法阻尼误差进行了理论分析,指出了附加振型法不存在由于阻尼假定不同而引起的误差,计算精度及效率均优于基于完全法的绝对位移直接求解法。
為提高已有絕對位移直接求解虛擬激勵法的求解效率及精度,對結構支座節點附加大質量塊併釋放支座約束,採用基于附加振型的振型分解法進行求解,附加振型來源于附加大質量塊。對附加振型、常規振型的振型特性和振型貢獻及計算效率進行瞭理論分析,分析錶明:通過構建少量附加振型就可精確捕穫結構擬靜位移,且隻需採用與相對運動法同等數量的常規振型就可精確捕穫結構動態相對位移,與Wilson位移輸入模式的絕對位移振型分解法相比,在保證計算精度的條件下可大大減少絕對位移求解所需的振型數。此外,對附加振型絕對位移求解法阻尼誤差進行瞭理論分析,指齣瞭附加振型法不存在由于阻尼假定不同而引起的誤差,計算精度及效率均優于基于完全法的絕對位移直接求解法。
위제고이유절대위이직접구해허의격려법적구해효솔급정도,대결구지좌절점부가대질량괴병석방지좌약속,채용기우부가진형적진형분해법진행구해,부가진형래원우부가대질량괴。대부가진형、상규진형적진형특성화진형공헌급계산효솔진행료이론분석,분석표명:통과구건소량부가진형취가정학포획결구의정위이,차지수채용여상대운동법동등수량적상규진형취가정학포획결구동태상대위이,여Wilson위이수입모식적절대위이진형분해법상비,재보증계산정도적조건하가대대감소절대위이구해소수적진형수。차외,대부가진형절대위이구해법조니오차진행료이론분석,지출료부가진형법불존재유우조니가정불동이인기적오차,계산정도급효솔균우우기우완전법적절대위이직접구해법。
Structures were solved using the pseudo excitation method with additional modes through adding big masses on support nodes in order to improve the calculation accuracy and efficiency of the old pseudo excitation method based on directly solving absolute displacements.The additional modes were caused by the added big masses.The contribution and characterisitics of additional modes and the conventional ones as well as the calculation efficiency of the new algorithm were analyzed.It was shown that constructing only few additional modes can capture the pseudo-static displacement responses of structures accurately,and adopting the same number of conventional modes obtained with the relative motion method can capture the same accurate dynamic relative displacement responses of structures;compared with the displacement input model presented by Wilson,the proposed method can lead to a significant reduction of the required modes for solving absolute displacements with the same accuracy;the calculation errors caused by different damping assumings don't exist in the new algorithm,so it is superior to the old pseudo excitation method based on directly solving absolute displacements in accuracy and efficiency.