Research On Shear Behavior Of Unreinforced Masonry Wall Strengthened By SGFRP

Due to the brittle materials, masonry structure has a vulnerable performance in earthquake. By the pass of using years and improvement of seismic defensive criterion, the problem is becoming outstanding that more and more masonry structures need to be strengthened. The masonry structures existing broadly in China and many historic buildings all over the world need to be repaired and strengthened.Fiber-reinforced Polymer Composites has key virtues, for its low weight, high strengths, easy to handle, endurance, good applicability, no appearance change of strengthened structures, etc. At present, a great deal of research is currently being conducted concerning the use of fiber reinforced plastic wraps or laminates in the repair and strengthening of masonry structures members in and out of the world, but a novel technique which further simplifies the application procedure is to apply the fiber using a spraying process. It sprays the fiber onto the member surface concurrently with a suitable matrix resin, a two dimensional random distribution of discontinuous fibers is obtained, in order to enhance the structural bending strength and shearing strength and improve the ductility and toughness of polymer. Nowdays, the research and the application of the technology mainly concentrate in the concrete structure reinforcement domain, yet the related research report is not seen in masonry structure. This research mainly discusses the feasibility and the superiority of the technique that is used on the shearing behavior of unreinforced masonry structures by SGFRP, through the finite element analysis the reasonable models and related numerical analysis results in the finite element analysis, in order to provide the basis of the experimental study and the ultimate bearing capacity of strengthed masonry structure.This paper expatitates Chinese masonry structural actuality and existing reinforced methods, the study and applications actuality of SGFRP strengthening technique, and the main modeling method on masonry structure by finite element analysis . Then using homogenized element models by finite element analysis, such characteristics as the internal stress, fracture spacing and the curve of load-displacement are generally analyzed, in order to investigate the factors such as different height-width ratio, various thickness and vertical compressed stress on the effects of the shear behavior, and the reinforcement effectiveness by SGFRP is studied though comparing the ultimate bearing capacity and maximum horizontal departure of the reinforcement wall. Meanwhile, the effects on the ultimate bearing capacity and the deformation ability are discussed with the thickness of the reinforcing layer. The analysis research indicates that the anti-shear supporting capacity of the walls reduced with the improving of the different height-width ratio and vertical compressed stress, and improves with the improving of the thickness of the wall; the ultimate bearing capacity and maximum horizontal departure of the reinforcement wall are improved by SGFRP, and with the thickness of the reinforced layers , the ultimate bearing capacity and the anti-lateral deformation ability improves. At last, this paper generally concludes the research on shear behavior of unreinforced masonry wall strengthened by SGFRP and presents some distinctive advices for further researching on SGFRP-reinforcement of masonry wall in the future.