ABSTRACT

The nonlinear dynamic analysis is the most sophisticated evaluation method for vertically irregular structures under the effect of the earthquake because the higher mode effects are significant. In particular, vertically irregular structure has a complex geometry, so errors can occur when inputting members as coordinates or when defining the properties of members. Therefore, a simplified modeling method is proposed in this paper. The proposed method was developed by converting vertically irregular structures to geometrically regular structures using a story stiffness equation. The results of modal analyses and nonlinear dynamic analyses obtained by both simplified and typical exact modeling methods were compared. As a result, the difference of fundamental period was about 11%, and the higher mode effects which were evaluated by ASCE 41 criterion governed in both models. In addition, the differences of story shear and story drift were about 15% and 24%, respectively. Therefore, the proposed simplified modeling method can be applied to initial structural design stages to save the project time by predicting approximate nonlinear dynamic results such as story shear, and story drift of vertically irregular structures.

摘要

由于高阶模态效应显着，非线性动力分析是地震作用下垂直不规则结构最复杂的评价方法。特别是垂直不规则结构具有复杂的几何形状，因此在输入构件作为坐标或定义构件属性时可能会出现错误。因此，本文提出了一种简化的建模方法。所提出的方法是通过使用层刚度方程将垂直不规则结构转换为几何规则结构而开发的。比较了通过简化和典型精确建模方法获得的模态分析和非线性动力分析的结果。结果，基本周期的差异约为 11%，以及由 ASCE 41 标准评估的更高模式效应在两个模型中都受到支配。此外，层剪切和层漂移的差异分别约为15%和24%。因此，所提出的简化建模方法可以应用于初始结构设计阶段，通过预测近似非线性动力结果，例如垂直不规则结构的层剪和层漂移，可以节省项目时间。