Research On The Finite Plane Truss Element Method And The Application In Engineering

Structural analysis plays a key role in the engineering design. Both analytic method in mathematics and traditional finite element method (FEM) have defects. The former can only resolve limited elasticity problems, while the latter can be used in much available situations. But it is more difficult to build displacement interpolating function and process huge data in FEM, the analysis results are always unstable in plasticity phase of material nonlinear. Aiming at plane stress problem, based on the fundamental of equivalent displacement in two structures with the same load and restrictions and the thought of FEM, a kind of novelelement------equivalent plane truss element(rectangle element and triangleelement) is constructed in this paper. The approximate calculation method realizes a simple and utilitarian solution to complicated two-dimension problems under tantamount precision. Further, this kind of element is applied in linear and nonlinear analysis of reinforced concrete(RC) structure and the equivalent plane truss element model of RC structure is proposed in the paper. Abundant examples prove that the method is applicable which can be referenced by in engineering.Firstly, focusing on plane stress problems, a kind of equivalent rectangle plane truss element is constructed in this paper, which converts complex two-dimension problems to one dimension problems. There are only axial force link elements in the new model under nodal loads, thus the internal force and deformation of elements becomes simple and explicit to be calculated and judged easily. Furthermore, it can meet the requirements of engineering precision.Secondly, in order to mesh various geometries and transitions, a kind of equivalent triangle plane truss element is constructed also.Thirdly, the equivalent plane truss element analysis program of plane stress problem is worked out, by which cantilever beam, simple beam and vertical structure are analyzed. The calculation results and other results of traditional FEM are consistent.Forthly, the transfer structure in High-Rise building and the frame-shell wall structure are analysised with the new elements in this paper. The linear analysis to a example of 12 floors with transfer beams and 10 frame-shell wall floors are worked. The results of stress and displacement have less differents with the results of 4-node shell elements. An wreck rules of equivalent plain truss element model...