考虑一个具有非粘滞阻尼特性的多自由度系统响应的时程分析问题。该非粘滞阻尼模型假设阻尼力与质点速度的时间历程相关,数学表达式体现为阻尼力等于质点速度与某一核函数的卷积。在利用状态空间方法将系统运动方程转换成一阶的状态方程的基础上,采用精细积分方法对状态方程进行数值求解,得到一种求解该阻尼系统时程响应的精确、高效的计算方法。通过两个数值算例表明,采用该方法得到几乎精确的数值计算结果,而且计算效率有成数量级的提高。
Abstract: Time-history analysis of a multiple-degree-of-freedom system with non-viscous damping is considered. In the non-viscous damped system, the damping force relates with the velocity time history by a convolution integral between the velocity and a decaying kernel function in its mathematical formulation. By transforming the equation of motion into a first-order extended state-space representation, the precise integration technique is employed to numerically solve the state-space equation. Two examples are given. The results show that the proposed method herein gives almost theoretically accurate solutions to the non-viscous damped system, and at the same time its computational efficiency has increased ten-fold.