Study The Contact Characteristics Of Finite Body Structure With Inclusions

Traditional mechanism design usually assumes that the interior of the material is uniform.However,in the actual processing of the material,it is inevitable that there will be non-uniform regions such as cavities,inclusions,and micro-cracks.It is precisely because of these non-uniform regions that the material contacts The characteristics changes and the strength decreases.If you use the contact characteristics of homogeneous materials to design the mechanism,the designed mechanism often fails to reach its expected life,and may even cause parts failure and some safety accidents.so it is very important to study the contact characteristics of heterogeneous materials.First,based on the Abaqus software,this article establishes a finite body sphere contact model with inclusions(spherical).By observing the plastic cloud image of the matrix,the position law of the initial yield of the sphere with inclusions is found.Different inclusion sizes,inclusion depths,and the matrix are studied.The influence of parameters on the critical pressure and elastic contact characteristics of the finite body sphere,and the corresponding relationship is obtained by fitting.At the same time,the influence of the inclusion parameters on the contact pressure of the substrate surface and the Mises stress distribution below the contact center was studied;the study showed that the pressure on the substrate surface increased with the increase of the inclusion radius and with the depth of the inclusion from the surface Decrease;when the inclusion is very close to the contact surface,no matter what value the inclusion radius takes,the surface pressure is significantly increased;The larger the inclusion radius,the greater the maximum Mises stress below the contact center,and the stress value decreases as the inclusion depth increases.Secondly,the elastoplastic properties of the finite sphere with inclusions were also studied,the influence of the inclusion radius and the inclusion depth on the first and second elastoplastic critical points of the matrix was obtained,and the corresponding relationship was fitted;The empirical expressions of the contact load and contact area are obtained by fitting the relationship between the contact load,contact area and the amount of depression of the matrix when the inclusion is included.The influence of the inclusion parameters on the contact pressure on the substrate surface and the Mises stress distribution below the contact center is discussedFinally,the contact analysis of the cylindrical and cubic inclusions with the same volume as the spherical inclusions is used;and the formula values obtained are compared with the results of the finite element calculations.The results show that the critical values obtained by the third and fourth fitting The contact load and contact area formulas also apply to the inclusion of cubes and cylinders of equal volume at the same location.The changes of the stress field and the surface contact pressure of the matrix when multiple inclusions are distributed inside the matrix are studied.The results show that the interaction between the hard inclusions will weaken the ability of each inclusion to concentrate the stress and the stress field inside the inclusion However,there will still be a large stress concentration,and the presence of soft inclusions will reduce the Mises stress in the inclusion area.The contact pressure will be significantly increased in the hard inclusion area,and slightly lower than the Hertz contact pressure in the edge area of the inclusion;the pressure value in the soft inclusion area also drops significantly,but the edge regions is slightly higher than the Hertz contact pressure.