R-Node method and its application in limit analysis of strip foundations

Limit analysis is very useful in the assessment and design of mechanical components and structures. Among the various methods for limit load estimation, approximate methods based on linear elastic finite element analyses are appealing to analysts and designers due to the conceptual insight, economy of computational effort and wide applicability. -- In this thesis, an approximate method for determining the limit loads of foundations on homogeneous and layered cohesive soils and cohesive-frictional soil is presented in detail. The results obtained for layered soils are presented as charts to be used for foundation design. This method makes use of the results of two or more linear elastic analyses. From these linear elastic analyses, load controlled locations called r-nodes are identified and limit loads are determined. The concept of r-nodes (redistribution nodes), which are akin to plastic hinge locations in a structure, forms the basis of this method. Several possible alternative ways of applying the r-node method to pressure-sensitive materials are also presented. -- The results obtained are compared with analytical results and elastic-plastic nonlinear finite element analysis results