Inside and outside boundary treatment method of isogeometric analysis

Abstract

The invention provides an inside and outside boundary treatment method of isogeometric analysis. The method includes the steps of establishing parameter space of the same topological structure with a part or a region, expressing the parameter space of the part or the region with open node vectors through a node insertion method, representing the surfaces of every three-dimensional body with normal and normal coordinates of the parameter space, generating open node vector expression of the surfaces of every three-dimensional body, calculating basis functions of the surfaces of every three-dimensional body in accordance with the obtained open node vector expression, and projecting inside and outside the boundary conditions of unknown field quantity in discrete function space through isogeometric analysis to complete boundary condition treatment. When the inside and outside boundary treatment method of isogeometric analysis is used for completing the boundary condition treatment of engineering problems, a numerical calculation problem can be converted into a logical judgment problem, and the logical judgment is more efficient than the numerical calculation and easier to achieve, so that the topological relationship judgment of isogeometric analysis is solved at higher efficiency.

Description

technical field [0001] The invention belongs to the technical field of finite element analysis, in particular to a method for processing inner and outer boundaries of isogeometric analysis. Background technique [0002] When using isogeometric method to deal with finite element problems, the CAD model of the simulated object should be established first, so that the CAD model can be expressed by NURBS base. For one-dimensional objects, the node vector of the corresponding parameter space is a non-negative ascending list of real numbers. For 2D and 3D objects, each object corresponds to two or three such lists. For a dimension, the information of all NURBS basis functions are stored in the node vector, such a node vector determines all basis functions in a dimension. [0003] There are usually multiple interacting parts (or regions) in a CAD model. Generally speaking, each part is expressed by an open node vector (Open Knot Vector). How to calculate open node vectors and NU...

AI Technical Summary

Problems solved by technology

Using traditional expressions, the above problems 1 and 4 can be handled simply, but the processing of other problems is more complicated and the calculation efficiency is low

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