SIMPLE-MODEL FOR DESIGN OF FRAMED-TUBE STRUCTURES

A very simple model for the analysis and design of framed-tube structures subjected to lateral loads is presented here. The structure is modeled as a series of stringers and shear panels. The elegance of the method lies not only in the simplicity and the accuracy of the method but also in the fact that all the necessary parameters are kept in the model so that design sensitivities can be generated, parametric studies can be carried out, and reasonable first estimates for the member sizes can be made. The model is viewed as an efficient design tool. The analytical expressions for the stresses and displacements are, for preliminary design, accurate and very easy to handle, so that the designer can attain the desired results. The model can be used directly for the analysis of structures that incorporate different materials and different properties along the height of the structure. A transfer matrix formulation has been developed and is presented for this purpose.