{"id":369058,"date":"2024-05-29T13:29:21","date_gmt":"2024-05-29T13:29:21","guid":{"rendered":"\/forum\/forums\/topic\/strain-calculation-at-gauss-point\/"},"modified":"2024-05-29T13:29:21","modified_gmt":"2024-05-29T13:29:21","slug":"strain-calculation-at-gauss-point","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/strain-calculation-at-gauss-point\/","title":{"rendered":"Strain calculation at Gauss point"},"content":{"rendered":"

Hi,<\/p>\n

I’m writing a code in MATLAB to calculate strains of a model using the 10-node tetrahedron element, SOLID 187. Using the shape function, I multiply the strain-displacement matrix B by the nodal displacements for each element to obtain the strains at the Gauss points, and then extrapolate these strains to the nodes.  While the strains generally match well for simple models, the error increases as the complexity of the model geometry increases. Decreasing mesh size does not lead to significant changes for the same geometry.<\/p>\n

 <\/p>\n

For a simple ring model, there were about 500 nodes where the error in the von Mises stress exceeded 5%, and as the model becomes more complex, the number of nodes exceeding 5% increases.<\/p>\n

<\/p>\n

<\/p>\n

Using PRESOL, loci to verify the Gauss points, I found a significant discrepancy in the x-direction between the Gauss point locations calculated in MATLAB and those expected. The other directions match well. Do ANSYS internally use different methods to calculate gauss points for complex geometries?  Could there be a reason for this issue?<\/p>\n","protected":false},"template":"","class_list":["post-369058","topic","type-topic","status-closed","hentry","topic-tag-matlab","topic-tag-strain"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t