A macroelement for the nonlinear analysis of in-plane unreinforced masonry piers
A macroelement for the nonlinear analysis of in-plane unreinforced masonry piers
复制标题
面内无筋砌体桥墩非线性分析的宏观单元
DOI：
10.1016/j.engstruct.2007.12.001
复制
发表时间：
2008
影响因子：
5.5
通讯作者：
T. Yi
中科院分区：
文献类型：
--
作者：
S. Chen;F. Moon;T. Yi
本文提出了一种能够模拟无筋砌体桥墩和桁梁面内响应的宏单元的公式和验证方法。所采用的建模方法最初是在20世纪80年代为钢筋混凝土墙的面内分析而开发的，该方法涉及将非线性剪切弹簧与旋转弹簧串联以模拟剪切和弯曲响应。在本研究中，将建模方法扩展到明确地处理URM特有的平面内失效模式。具体来说，提议的宏观单元包括一个轴向弹簧、三个剪切弹簧和两个旋转弹簧，以模拟在过去的URM桥墩试验中观察到的轴向、床节点滑动、对角张力和摇晃/脚趾破碎破坏模式。该宏观单元的验证与过去21项URM桥墩行为的实验研究进行了比较，主要集中在极限强度和破坏模式模拟上。总体而言，宏单元正确地模拟了67%的报告破坏模式，并提供了平均绝对误差为19.1%的强度估计。这些错误主要归因于URM响应的可变性，以及在没有报告的材料特性的情况下使用默认材料特性所带来的不确定性。砌体默认对角抗拉强度“校准”后，平均绝对误差降至11.9%；然而，预测的失效模式数量保持不变。最后，利用所提出的宏观单元进行了垂直应力、纵横比和边界条件的参数化研究。
This paper presents the formulation and validation of a macroelement capable of simulating the in-plane response of unreinforced masonry (URM) piers and spandrels. The modeling approach adopted was originally developed for the in-plane analysis of reinforced concrete walls in the 1980s, and involves placing nonlinear shear springs in series with rotational springs to simulate both shear and flexure response. For this study, the modeling approach was extended to explicitly address the in-plane failure modes unique to URM. Specifically, the proposed macroelement includes an axial spring, three shear springs, and two rotational springs to simulate the axial, bed joint sliding, diagonal tension, and rocking/toe crushing failure modes observed during past URM pier tests. The validation of this macroelement involved comparison with 21 past experimental studies of URM pier behavior, and focused primarily on ultimate strength and failure mode simulation. Overall the macroelement properly simulated 67% of the reported failure modes and provided strength estimates with an average absolute error of 19.1%. These errors are primarily attributed to the variability of URM response as well as the uncertainty associated with using default material properties in the absence of reported material properties. Following the ‘calibration’ of the default diagonal tension strength of masonry, the average absolute error was reduced to 11.9%; however, the number of failure modes predicted remained unchanged. Finally, the proposed macroelement was used to carry out parametric studies of vertical stress, aspect ratio, and boundary conditions.