修正CD-Newmark组合积分算法的数值特性研究

Research on characteristics of modified CD-Newmark combined numerical integral algorithms

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特点,为解决传统CD-Newmark算法中上限频率取值较大而导致时间步长变小的缺点,对CD-Newmark算法进行参数修正,将计算子结构的所有被嵌固自由度释放,分别得到试验子结构的稳定条件和计算子结构无条件稳定的参数合理取值范围,并对计算精度进行分析,通过算例分析验证算法的数值特性,从而初步解决了CD-Newmark算法存在稳定性界限过严的问题,可为结构抗震拟动力试验提供研究参考。

Combined numerical integral algorithms is combined with advantages of explicit numerical integral algorithms without iteration and inexplicit numerical integral algorithms unconditionally stable. In order to solve the problem of traditional CD-Newmark algorithm has the bigger upper frequency leads to a small time step,a modified CD-Newmark combined numerical integral algorithms release the fixed degrees of freedom of calculational substructure,then the parameters range of stable condition of experimental substructure and the unconditionally stable of calculational substructure are obtained,and the accuracy analysis is also studied. A numerical examples is carried out to verify the algorithm,then solve the strict stability problem of the CD-Newmark algorithm. The study provides reference for structural seismic pseudo dynamic test.