CAJ | 학술논문

进行大跨桥梁地震反应分析时以结构位移反应峰值误差为目标函数，建立求解 Rayleigh 阻尼系数的优化分析方法。考虑基频模态为结构动力反应的最显著贡献模态，以基频模态阻尼比等于精确值为约束条件，形成求解 Ray-leigh 阻尼系数的约束优化方程；以840 m 长斜拉桥为例分析 Rayleigh 阻尼系数随优化计算模态数及参考自由度变化规律。与传统 Rayleigh 阻尼比较，讨论不同阻尼模型对结构位移、内力计算误差。数值计算结果表明，该方法可有效降低位移、内力计算误差，避免人为选择参考频率所致任意性，适合工程结构计算与分析。
진행대과교량지진반응분석시이결구위이반응봉치오차위목표함수，건립구해 Rayleigh 조니계수적우화분석방법。고필기빈모태위결구동력반응적최현저공헌모태，이기빈모태조니비등우정학치위약속조건，형성구해 Ray-leigh 조니계수적약속우화방정；이840 m 장사랍교위례분석 Rayleigh 조니계수수우화계산모태수급삼고자유도변화규률。여전통 Rayleigh 조니비교，토론불동조니모형대결구위이、내력계산오차。수치계산결과표명，해방법가유효강저위이、내력계산오차，피면인위선택삼고빈솔소치임의성，괄합공정결구계산여분석。
For the seismic response analysis of long span bridges,an optimal analysis method was proposed to solve Rayleigh damping coefficients.In the method,the errors of structural displacement peaks were taken as the optimization objective function.Meanwhile,considering that the fundamental-mode contribution is usually significantly larger than others,the constraint condition was described as the equivalence between the modal damping ratio of fundamental mode and the exact value.So,a constraint optimization equation was developed for solving Rayleigh damping coefficients. Then,the effects of the modes number and the referencial degrees of freedom in optimization calculation on the evaluation of Rayleigh damping coefficients were investigated,taking a 840m-long cable-stayed bridge as an example.Comparing with the traditional Rayleigh damping,the errors of structural displacements and internal forces under four kinds of earthquake excitations were discussed.The numerical results show that the proposed method can reduce the calculation errors of displacements and internal forces effectively,and avoid the artificial selection of referencial frequencies,which is suitable for calculation and analysis of engineering structures.