Geometric reconstruction method based on finite element model

Abstract

The invention provides a reconstruction algorithm for a finite element discretized geometric model. The reconstruction algorithm comprises the following steps: firstly, inputting a finite element discrete grid to determine a grid topological relation, and adding a steady-state thermal field value to a grid node by solving a Laplace partial differential equation; secondly, extracting surface gridsand boundaries of a model, and setting a reasonable threshold value according to a geometric discrete boundary vector value to determine an isothermal surface; performing overlapping removal, extracting an isotherm and a domain boundary, setting an objective function to perform boundary intersection operation, judging the parity of sub-domains according to an intersection result, and setting an objective function for different sub-domains to perform reasonable quadrilateral sub-domain division; and finally, carrying out discrete boundary sorting and boundary fairing on the sub-domains, obtaining control points in the sub-domains through linear interpolation to realize B-spline parameterization, and verifying the accuracy of reconstructed geometry by utilizing isogeometric analysis. Exampleresults show that the algorithm provided by the invention well solves the geometric reconstruction problem of the finite element model.

Description

technical field [0001] The invention is applied in the field of body parameterized geometric reconstruction in reverse engineering, and is a method for realizing B-spline body parameterized expression specially for finite element discretized geometric models. Background technique [0002] Before the B-spline body parametric model is constructed, the complex model is divided into quadrilateral or hexahedral subdomains. This operation is similar to the subdomain generation in traditional finite element mesh generation. For a long time, subdomain generation in finite element has been realized by manually cutting entities, and the recent rise of isogeometric analysis technology urgently needs to solve the disadvantages caused by manual segmentation. The method of quadrilateral grid automatic domain division is more based on triangulation as the underlying grid, and on this basis, the grid merging algorithm is used to divide the geometry into large quadrilateral domains, such as:...

AI Technical Summary

Problems solved by technology

Generally, a series of grid operations are used to realize the subdomain segmentation of the four-sided grid model, and then reconstruct it into a volume parameterized model. These methods can handle any two-dimensional model, but the algorithm relies more on some empirical parameters, and it is difficult to Realize the mapping from two-dimensional area to three-dimensional geometry, the reconstructed model contains many singular points inside, the reconstruction quality is poor, and high-order continuity cannot be achieved inside the domain

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