Analyses Of Internal Forces Of The Building Floor And Concealed Beams Under Partitions With Finite Element Method

In current structure design, calculating the internal forces of the floor under the vertical load, the secondary girder, main gird and shear wall of the reinforced concrete floor system are always be assumed as bearing without vertical deformation. The calculations of elastic and plastic analysis of both one-way slab and two-way slab are based on this assumption. Because these assumed bearings, to some extent, are deformed,the assumption causes inaccuracy and even mistakes of the calculation results.This paper makes elastic analysis on the floor internal forces of a building using shear-wall structure via the large-scaled GM structure analysis software called ANSYS, compared with the result made by the traditional design way, it is found that the traditional design way is obviously existing blemishes. So, the writer strongly advises the engineering circle to adopt finite element method to make analysis on internal forces with design software ETABS.Currently, the calculation way of PKPM, common engineering design software, is in accordance with the traditional hand-made calculating method. So, the PKPM calculation data in this paper represent the calculation result of internal forces made by the traditional way.In residential building design, probably we will install partition to divide a big space, and for the sake of good look always the designer will install concealed beam to support the partition. As for the concealed beam, namely, it is the beam with the same thickness as the slab. The concealed beam could install enough longitudinal reinforcement to support the vertical load made by the partition, and sometimes two concealed beams would intersect.At present, there is no national code for the design of such concealed beams, and even the experiments and researches on concealed beams are countable. To make clear of some key problems, such as whether two intersected concealed beams could support each other, or the reinforcing steel bar installed by the designer ever makes function. The article uses reinforced concrete three-dimension nonlinear finite element analysis model to make simulated analysis on a concealed-beam-contained residential building, yielding the result that the intersected concealed beams cannot obviously support each other; hence it proposes the advice for concealed beam design. The model adopts solid65 element simulated reinforced concrete, and such element can simulate the cracks and crushing with William-Warnke criteria。Using link8 element simulated reinforcement, the characteristic of which is multilinear kinematical hardening, and no bonding-losing effect is considered in the model.Meanwhile the article makes a detailed explanation to FEM theory and its related knowledge, such as FEM basic, the use of FEM and computer technique in engineering field, introduction to various common finite element software, constitutive relation of reinforced concrete, failure criteria and partial element characteristics of ANSYS, etc.