考虑阻尼影响的修正CD-Newmark组合算法数值特性研究

显-隐式组合数值积分算法结合了显式算法无需迭代和隐式算法无条件稳定的各自优点,是结构抗震拟动力试验顺利运行的关键.在对传统显式中央差分法和隐式Newmark β组合算法进行参数修正的基础上,建立了修正CD-Newmark算法,考虑阻尼的影响分析了组合算法的稳定性条件、周期失真率和数值阻尼比,分别得到了试验子结构的稳定性条件和计算子结构无条件稳定的参数合理取值范围,并对计算精度进行了分析.通过算例分析验证了算法的数值特性,从而初步解决了CD-Newmark算法存在稳定性界限过严的问题,为结构抗震拟动力混合试验提供了研究参考.

Stability and Accuracy of Modified CD-Newmark Combined Numerical Integral Algorithms with Consideration of Damping Effect

It is the key to the substructure seismic pseudo-dynamic test to combine with advantages of explicit numerical integral algorithms without iteration and inexplicit numerical integral algorithms unconditionally stable.In this paper,a modified CD-Newmark combined numerical integral algorithm was established based on the parameter modification of traditional central difference algorithm and Newmark β algorithm.Considering the effect of damping,the analysis of the stable condition,the cycle distortion rate,the numerical damping ratio were carried out,then the parameters range of stable condition of experimental substructure and the unconditionally stable of calculated substructure are obtained,and the accuracy analysis is also studied.A case study is carried out to verify the algorithm,and then solve the strict stability problem of the CD-Newmark algorithm.Our study provides a reference for structural seismic pseudo dynamic test.