New submodel finite element analysis method based on cutting boundary deformation constraint

Abstract

The invention discloses a new submodel finite element analysis method based on cutting boundary deformation constraint. The content of the method comprises: building a complete machine simplified model, analyzing; carrying out postprocessing to cutting boundary nodes of the complete machine model; building a finite element model-a submodel of a partial structure; adding a deformation coupling constraint equation to the cutting boundary of the submodel, adding a displacement interpolation boundary condition and a force boundary condition; analyzing the submodel; and checking that the distance from a cutting boundary to a stress gathered region is far enough. The method of the invention is advantaged by that when applying the boundary conditions to the cutting boundary of the submodel, the displacement interpolation boundary condition is added to one part of the cutting boundary, the constraint equation and the force boundary condition are added to the other part; the accuracy of the boundary conditions of the submodel is ensured; compared with the traditional submodel finite element analysis method, in adoption of the new submodel finite element analysis method, the demand of the complete machine model is reduced; the complete machine model is greatly simplified; and the complete machine analysis efficiency and the calculation precision of the submodel are improved.

Description

technical field [0001] The invention relates to a sub-model finite element analysis method, in particular to a new sub-model finite element analysis method based on cutting boundary deformation constraints. Background technique [0002] Facing the development trend of large-scale mechanical equipment today, the problem of finite element analysis of the whole machine structure of large-scale machinery is becoming more and more prominent. There are many parts and complex structures of large-scale mechanical equipment. In order to realize the analysis and calculation of the whole machine during the finite element structural analysis, it is necessary to greatly simplify the model of the whole machine on the premise of ensuring the accuracy of the overall deformation and force transmission. Ensure that the scale of the model is within the allowable range of computer capabilities. At this time, some local simplified structural stress and strain characteristics cannot be calculated...

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Problems solved by technology

However, when the stiffness of the sub-model differs greatly from the stiffness of the sub-model in the overall model, it is not feasible to apply boundary conditions.

This is because when the stiffness of the submodel changes, if the force on the cutting boundary remains unchanged, the submodel will undergo rigid body displacement, U 1 A part of it becomes an unknown quantity. At this time, still applying the calculated displacement of the cutting boundary of the whole model will lead to errors in the stress distribution of the sub-model

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