Force–displacement curves of M1.

The in-plane seismic behavior of unreinforced masonry (URM) structures is closely related to the aspect ratio of the wall and vertical load. The purpose of this study was to investigate the difference between the failure mode of the model and the horizontal load using the finite element model (FEM) under the action of aspect ratio (0.50 to 2.00) and vertical load (0.2 MPa to 0.70 MPa). The overall macro model was established using the Abaqus software, and the corresponding simulation was performed. The simulation results indicate that: i) the shear failure and flexural failure were the main failure modes of masonry walls; ii) shear failure could be viewed as the main failure mode of the model when the aspect ratio was less than 1.00; however, the flexural failure was considered to be the main failure mode of the model once the aspect ratio was greater than 1.00; iii) when a vertical load of 0.20 MPa was applied to the model, only flexural failure was observed, regardless of whether the aspect ratio of the model increased or decreased; the flexural shear mixed failure was captured within the range of 0.30 MPa– 0.50 MPa; the shear failure was the main failure mode within the range of 0.60 MPa– 0.70 MPa; and iv) the wall with an aspect ratio less than 1.00 could bear a higher horizontal load, and the increase in vertical load can significantly improve the horizontal load of the wall. In contrast, once the aspect ratio of the wall reaches or exceeds 1.00, the increase in the vertical load has little effect on the increase in the horizontal load of the wall.无筋砌体（unreinforced masonry, URM）结构的平面内抗震性能与墙体高宽比及竖向荷载密切相关。本研究旨在采用有限元模型（finite element model, FEM），探究在高宽比（0.50~2.00）与竖向荷载（0.2 MPa~0.70 MPa）作用下，砌体模型的破坏模式与水平荷载之间的关联差异。本研究通过Abaqus软件建立整体宏观模型，并开展了对应的数值模拟。模拟结果表明：① 砌体墙体的主要破坏模式为剪切破坏与弯曲破坏；② 当高宽比小于1.00时，模型以剪切破坏为主；当高宽比大于1.00时，模型则以弯曲破坏为主；③ 当模型承受0.20 MPa的竖向荷载时，无论高宽比如何变化，仅观察到弯曲破坏；在0.30 MPa~0.50 MPa的竖向荷载范围内，墙体呈现弯剪混合破坏；在0.60 MPa~0.70 MPa范围内，则以剪切破坏为主；④ 高宽比小于1.00的墙体可承受更高的水平荷载，且竖向荷载的提升可显著提高墙体的水平承载能力；与之相反，当墙体高宽比达到或超过1.00时，竖向荷载的提升对墙体水平承载能力的提升作用极小。