Research And Implementation Of Triangular Mesh Finite Element Model For Direct Generation Of Industrial CT Image

Reverse design is an important technical means for advanced product technology tracking,technology digestion and new product optimization and innovation.Remanufacturing technology rejuvenates old machinery and equipment.These two technologies have been widely used in enterprise production design;Restricted by measurement methods,the technical digestion and remanufacturing of advanced products with complex internal cavity structures have always been a problem faced by enterprises.Industrial CT can display the internal and external structure of the measured workpiece in the form of slice images under non-destructive conditions,providing a new technical method for the reverse design and remanufacturing of products with complex internal cavity structures.However,the current reverse design and remanufacturing based on industrial CT images still have the problems of difficult quantitative analysis and low degree of automation.Based on this,industrial CT technology is combined with finite element analysis technology in the subject,and a method of directly generating triangular mesh finite element models from industrial CT image was proposed to achieve finite element analysis of products at specific sections or localities.An application system module was developed to automate the operation process.The main research content and work are as follows:1)In order to ensure the effectiveness of finite element analysis,a method to determine the model boundaries and nodes accurately was proposed.Firstly,the sub-pixel edge detection method was used to identify the contour line and determine the type value point;then,the boundary of the finite element model was generated by Bezier curve fitting;finally,the idea of the dual surface was extended from the position and normal information to the area,the quadratic error function was used to accurately determine the minimizer of the boundary area,and determine the model nodes.2)Aiming at the current problem that the triangulation has a large amount of calculation and is not suitable for industrial CT image segmentation.A fast meshing algorithm based on the minimum distance between two nodes was proposed to improve the Delaunay triangulation,which greatly improved the efficiency of meshing and can also realize the generation of the initial triangular mesh finite element model of industrial CT image.3)In order to generate a high-quality triangular mesh finite element model,a method to optimize the mesh model from both angle and topology was proposed.First of all,the mesh side length ratio and twist angle commonly used in engineering are selected as the triangular mesh quality evaluation indicators;then,a combination of inserting nodes and node fusion was proposed to optimize the angle;finally,the side flip was used to optimize the angle normalized mesh model to obtain a high-quality triangular mesh model.4)Based on the VS 2016?Qt5.5 and the Open GL graphics display library,an industrial CT image directly generated triangular mesh finite element model application system module was developed to realize the automation of the conversion process and has been successfully applied in enterprise design.