基于DDA和FEM的砌体结构震动分析

运用非连续变形分析（DDA）和有限元方法(FEM)对砌体结构进行震动分析。建模中将砌体结构的砖、柱、过梁以及楼板等视为独立的弹性体分别作有限元划分，弹性体之间运动由接触界面的张开、闭合和滑动控制来实现，通过防止弹性体间的侵入来校正弹性块体系统的位移与应变最小二乘拟合结果。弹性块体间滑动采用库仑摩尔定律控制砂浆的作用与失效，输入相当于地震烈度Ⅸ度的加速度峰值的迁安波对砌体结构模型进行震力分析，研究相应震动过程。算例表明，DDA和FEM组合的方法能很好地模拟砌体结构受地震作用的动力响应过程。在较大地震作用下，砌体结构首先从底层开始开裂破坏并导致结构倒塌，与农村砌体结构震害现象吻合较好。

Earthquake Response Analysis on Masonry Structural by Discontinuous Deformation Analysis and Finite Element Method

This paper uses discontinuous deformation analysis and FEM to study the earthquake response analysis on masonry structures. In the modeling process, the bricks, columns, lintels and floors in the masonry structure are regarded as independent elastomer. Each elastomer is classified as a finite element. Movement among the elastomers is based on the opening, closure and slide control of the contact interface. To prevent the intrusion of elastomer we correct the results of least-square of displacement and strain to the simulation system. We use Coulomb-Moore’s law to control the function and failure of mortar’s forces among elastomers. We input the peak acceleration equal to the seismic intensity of Ⅸ degrees of Qianan wave in the masonry structure model for dynamic analysis and to study the whole seismic response process. The analysis of the example shows the methods of DDA and FEM can simulate the dynamic response process of masonry structure subjected to earthquake very well. Under the effect of a large earthquake, the bottom of masonry structure firstly began to show cracks and then led to structural collapse. This agrees with the earthquake damage phenomena seen in rural masonry structures in real large earthquakes.