An Evaluation Method of Assembly Contact Stress Distribution Based on Entropy Theory

Abstract

The invention discloses an entropy theory based assembly contact stress distribution assessment method which includes the steps of firstly, building a measurement coordinate system and a three-dimensional solid model to a to-be-tested part, subjecting the three-dimensional solid model to finite element cell meshing, and calculating strain energy density of each cell; secondly, calculating the overall entropy estimate value, the overall maximum entropy, the overall normalized entropy value Hs according to the strain energy density of each cell; thirdly, judging whether Hs is greater than or equal to the set threshold value, if so, then taking Hs as an assessment index to assess assembly stress distribution uniformity of surfaces of the to-be-tested part, and if not, then going to the next step; fourthly, building multiple sections perpendicular to the Z-axis of the measurement coordinate system; fifthly, searching a section with convex hulls of which quantity and area accounting for the maximum ratio to the surface area of the to-be-tested part, and calculating the convex hull height entropy estimate value, the convex hull height maximum entropy, and the convex hull normalized entropy value Hcs; sixthly, building the assessment index Ec that is equal to AHS + BHCS; and finally assessing the assembly stress distribution uniformity of the surfaces of the to-be-tested part according to the assessment index Ec.

Description

technical field [0001] The invention belongs to the field of manufacturing quality prediction and control, and in particular relates to an assembly contact stress distribution evaluation method based on entropy theory. Background technique [0002] In precision mechanical systems, different shape error distributions on the surface of parts will lead to different contact states between mating surfaces. Under a certain assembly force, different assembly contact states will form different non-uniform contact stress distributions and cause different additional deformation errors, resulting in different assembly errors. In addition, the non-uniform stress field generated by the parts caused by non-uniform contact will release the energy of the non-uniform stress field with the change of time, temperature and mechanical environment, which will change the assembly accuracy. Research shows that for mechanical systems with low precision requirements, the influence of non-uniform con...

AI Technical Summary

Problems solved by technology

Studies have shown that for mechanical systems with low precision requirements, the impact of non-uniform contact stress distribution on assembly accuracy is not significant, but for precision mechanical systems, assembly contact stress distribution will have a significant impact on assembly accuracy

Traditional geometric error evaluation methods cannot reveal the influence of assembly contact stress distribution on assembly accuracy

Images