The Internal Force Analysis Method Of Masonry Structure With Openings

Masonry structure is still necessary for the new construction, and it occupies a large proportion in the existing structure. Due to the limitations of their own characteristics,masonry structure is damaged seriously in the previous earthquake. Wenchuan earthquake damage phenomena show that on the one hand, the existing design method of masonry structure in our country is unable to make a reasonable explanation to the phenomenon of earthquake damage; on the other hand, the failure mode of the masonry structure has a great influence on the seismic behavior of the masonry structure.According to the problems found in earthquake, combing with the finite element software ABAQUS, this paper focuses on wall openings in masonry structure,and do the further research on the factors of wall openings, failure mode influencing factor and equivalent frame method. All the works is as follows:1. Through the analysis of the seismic damage of masonry structures in Wenchuan earthquake, three failure modes of masonry structure wall opening are summed up, and the shortcomings of the seismic design method of masonry structure at present are pointed out.2. The mechanical behavior of multi-story masonry structure under horizontal load is systematically analyzed, and the main factors affecting the failure mode of masonry structure are revealed.3. According to the general mechanical behavior of masonry structure under earthquake action, a proposal for the analysis of the mechanical properties of masonry structures by equivalent frame is presented. Based on the finite element analysis of the stiffness ratio of different wall, a method to determine the relative size of the joint stiffness is proposed.4. With reference to the wall frame, considering the influence of wall shear, bending deformation and node rigid zone, the internal force analysis method of the wall of masonry openings is established. The stiffness of wall between windows and the spandrel wall is determined, and the inflection point of the equivalent frame is simplified and modified. Based on the seismic design method of "strong column and weak beam" and the method of equivalent frame internal force analysis, the method of the failure mode of the wall between windows before the spandrel wall is proposed.The significance of the research: The equivalent frame model can not only better reflect the mechanical behavior of masonry structure under earthquake action, but also is easy to control the failure mode of masonry structure. The method can be used as a simplified method in engineering practice, which provides reference for overcoming the shortcomings of the present seismic design method of masonry structures.