Effects of aspect ratios and vertical loads on in-plane seismic behavior of unreinforced masonry walls: A numerical simulation.

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.