Research On The Normalization Of Meshed Surface Aimed To Tool Path Generation

With the development of CAE technology, the finite element simulation analysistechnology can predict and compensate forming defects accurately, therefore, the NCmachining based on the finite element compensated model can greatly shorten the productdevelopment cycle. Triangular mesh model is widely used in the engineering software ofCAE/CAM, because of its simple data structure, adaptable topology and rapid flexiblemodeling. So the research about triangular mesh after finite element analysis is of greatsignificance, which is for NC machining.This thesis mainly studies the triangular mesh model after finite element analysis,which has been trimmed and adaptive subdivided during stamping. The model has manydefects when based on STL file for data processing. Aiming at these defects, this thesisproposes a solution that works well, to obtain high-quality triangular mesh model for NCmachining. The thesis mainly did the following work:Firstly, based on distance formula of space point to surface and the Newton iterationmethod, the thesis researched the degree of approximation of triangular mesh surface andits original free-form surface, and got the principle of free-form surface triangulation inCAE software.Secondly, this thesis studied the criterion of triangular mesh adaptive subdivisionduring stamping in CAE software, and analyzed the influence of subdivision to thetriangular mesh model and its STL file. Due to the influence, the thesis used trianglecircumcircle and line length to deal with it.Thirdly, through researching the STL file format of triangular mesh model, using thelogical relationship of triangle vertex and normal vector in STL file to make all thetriangles’ edges ordered. After doing this, this thesis used ordered triangle edges to dealwith the quadrilateral gap of mesh model on trimming boundary.Finally, an example combining with Loop triangular mesh subdivision is given,analyzing the shape of defects on mesh surface through global and adaptive Loopsubdivision. After defining the quality of triangle, this thesis analyzed the quality oftriangles on processed mesh surface, and it showed the approach has a good effect. Thethesis’s work is an important element work for NC machining tool-path planning.