Simplified analysis of wall-frame structure with columns and girders of unequal lateral dimension

Abstract

Wall-frame structures in high rise buildings very often Comprise columns and girders whose lateral dimensions (i.e. the depth of column and width of girder) are Unequal. ~ simplified method of calculating the stresses and deflec_ tions in such structures, sUbjected to lateral loads, is presented. The accuracy of the method is verified by analyzing a 10-storey wall-frame and comparing the results of the simplified method with those obt~ned from a finite element analysis and a continuous medium analysis. The method, originally propOsed by A.H. Khan for wallframe structures of uniform thickness, consists in dividing the original structure into a discrete number of 'modules' which are then replaced by uniform plate elements of same height and width as the parent module and same thickness as that of column of the parent module, but having analogous stiffness properties. This report presents the results of an effort to extend Khan's method to structures where the lateral dimension of columns and girders are unequal. General computer programmes for the analysis of wall_ frames, subject to lateral load, have been developed Using the following three methods: i. Simplified Method ii. Finite Element Method and iii. Continuous Medium Method ii, Wall-frames consisting of variable thickness columns and girders are analysed by the proposed simplified method and the results are compared with those obtained by continuous Medium Method and Finite Element Method. The values of stresses and deflections obtained from the simplified method agree well with these obtained from a finite element analysis and from continuous medium method.