Numerical Study of NSM FRP Strengthened Masonry Walls

The application of external reinforcement with fiber reinforced polymer (FRP) to increase structural behavior of masonry structures has been a research focus area during the past decade. The near-surface mounting (NSM) technique is a relatively new retrofitting technique involves bonding FRP bars/strips insert into grooves cut into the surface of masonry. A numerical study was carried out to investigate the in-plane shear behavior of brick masonry wall strengthened with NSM FRP strips. A 2-D finite element (FE) model was used to simulate the structure behavior of strengthened masonry walls. The masonry was modeled by micro-modeling approach and FRP strips was modeled as attaching to the masonry mesh using the shear bond-slip relationships determined from experimental pull tests. The key shear behaviors of strengthened masonry wall panels in diagonal tension/shear tests was produced, including load-displacement response, crack development, and reinforcement contribution. Then, a parametric study was carried out to examine the contribution of different material and geometry property of FRP strips in the load carry capacity and shear ductility of strengthened masonry wall panels. Finally, the FE modeling for a real façade predicts the improvement of shear resistance which contributed by NSM FRP strengthening.