基于SAP2000 API的模态缩减法在高层建筑动力分析中的应用

为解决高层建筑自由度数目巨大导致其动力响应分析工作量大、效率低的弊端,文章在基于SAP2000API接口的基础上,分别运用原有结构整体刚度（静力凝聚法）和结构振型（SEREP法与MODAL法）3种不同方法,对高层建筑建立了简化为“葫芦串”体系的模态缩减方法.算例计算表明,直接基于原有结构整体刚度的模态缩减方法,对于结构的前几阶振型,具有较高的模拟精度；而基于结构振型的模态缩减方法（SEREP法与MO-DAL法）在所取的振型阶数范围内,能够完全一致地保留原结构的振动特性；而在所取的振型阶数范围外,相比于SEREP法,MODAL法能够大致反映结构的振动情况.由于对高层建筑动力分析通常只考虑前几阶模态的情况,文章结合SAT2000 API应用程序接口的功能,应用上述3种模态缩减方法,为自动化和高效化地实现高层建筑动力分析提供了良好的条件.

Application of model order reduction method in dynamic analysis of tall building via SAP2000 API

Based on the SAP2000 API interface system, three model order reduction methods, which are stated as Static Condensation （Guyan） method, SEREP method and MODAL method, were applied in this paper to obtain the condensed system matrix （ stiffness and mass matrix） of tall building with very complicated structural system and large degree of freedom. Numerical analysis for a 20-story tall building showed that the results obtained from static condensation method could have enough accuracy in modeling the dynamic characteristic of the first few modes for the original complex structural system; while SEREP and MODAL method could exactly preserve the dynamic characteristic of the selected vibration mode for the original full model. The reduced system matrix from MODAL method also can predict the natural frequency of the residual modes while SEREP method can not predict effectively. The combined application of SAP2000 API and three model order reduction methods in this paper could be utilized to solve the dynamic problem of large and complex tall building system automatically and effectively.