PSI - Issue 70

Chaitra Shree V. et al. / Procedia Structural Integrity 70 (2025) 67–73

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3. Finite Element modelling Geometry for the finite element modelling were drawn using AutoCAD Software. Static Structural nonlinear analysis was carried out to study the combined loading behavior of infill wall. Geometry of infill wall is considered for study as shown in Fig. 1. The infill wall was modeled as a solid continuum using the Solid186 element, which supports plasticity and large deformation analysis. A hex-dominant meshing strategy was applied to the entire assembly, with a finer mesh resolution (50 mm) over the masonry region to capture localized strain gradients and crack propagation. Meshed model is shown in Fig. 2. Frictional contact interfaces (friction coefficient 0.3) were defined between the masonry and the RC frame to allow relative sliding and detachment during nonlinear loading. Loading conditions included a vertical axial load of 10 kN applied to the top beam to simulate gravitational forces, along with a horizontal displacement-controlled lateral load applied quasi-statically to replicate in-plane seismic effects. Fixed boundary conditions were assigned to the base of the columns. The analysis was performed under large deformation assumptions with automatic time stepping and convergence based on force residuals. The failure response was assessed through contour plots of equivalent plastic strain, principal stress trajectories, and the evolution of reaction forces under increasing lateral displacement. To validate the numerical results, analytical estimations of the shear capacity were performed using MATLAB. The classic empirical formula, which considers cohesion and frictional resistance under axial load, was used to estimate the shear strength of the wall. MATLAB scripts processed exported nodal displacements and reaction forces from ANSYS to generate lateral force – displacement curves and verify peak strength values. This combined numerical and analytical methodology enabled a comprehensive understanding of infill wall failure behavior under complex loading conditions.

Fig. 1. (a) Geometry of infill wall (b) Meshed model of infill wall

4. Results and Discussion This section presents the nonlinear finite element simulation results of the infill masonry wall embedded within an RC frame, modeled using the Drucker-Prager (DP) plasticity criterion. The analysis focused on identifying crack initiation, propagation mechanisms, and ultimate strength under simultaneous axial and lateral loading. Results were validated using analytical predictions based on cohesion-friction models and compared with expected trends from literature. FEA results obtained are shown in fig.2. The lateral load vs. displacement curve obtained from ANSYS showed an initial linear response followed by a nonlinear softening stage, as illustrated in Fig. 3. The wall exhibited stiff behavior initially due to confinement from the RC frame, but as the lateral displacement increased, cracking began to develop along the diagonal tension zone. Beyond peak strength, a rapid drop in lateral resistance was observed, indicating brittle failure dominated by shear-compression interaction.