Push over Analysis of Steel Strengthened Masonry

Strengthening of un-reinforced masonry (URM) structures to improve its seismic performance is not only well recognized among the research community but also getting attention of practicing engineers around the globe. The estimation of lateral capacity and performance of masonry becomes complex because of heterogeneous nature of its constituent materials and other associated problems. Heterogeneous and homogenous approaches are generally adopted for analysis of masonry. In heterogeneous approach, bricks, joints and bed mortar are modeled separately whereas; in homogeneous approach the masonry is modeled as one continuum body. Earlier approach requires more efforts but level of accuracy of both the approaches is almost same. In the present work, the homogenous approach is used to model the masonry wall panels. The behaviour of the un-reinforced and steel strengthened masonry wall panels is determined from push over analysis using a commercial finite element package MSC-MARCS 2003. The aim of this analysis was to study the lateral load– displacement behaviour and failure mechanism of strengthened masonry under monotonic lateral loading. Four single leaf panels with aspect ratio of 1.0 were constructed on strong floor of structural laboratory. The square panels having dimension of 1200 mm were constructed using same type of material and workmanship. Of them; one wall panel was unreinforced reference and remaining were strengthened with square steel mesh. Firstly the specimens were tested till failure under monotonic lateral loading and later finite element analysis of the same specimens was carried out using MARCS2003. The analytical lateral force lateral displacement relationship and region of stress concentrations were analyzed to depict the lateral capacity and failure mechanism of strengthened masonry wall panels. At the end the analytical results were compared with the experimental recorded values and the analytical results were found in good agreement with the experimental values.