The Finite Element Analysis And Experimental Study Of Fastener Forming Based On DEFORM-3D

Fasteners are a kind of mechanical parts,which connect and fix a number of parts or components together.They can be applied variously from civilian products to military supplies,and are often seen as bolts,studs,screws,nuts,washers and other parts in daily life.Fasteners can be deformed easily during the molding process,and are easy to have defects like burr,folded,filling shortage of mold cavity,which will lead to the reduction of the molding quality of fasteners and the restriction of the application of fasteners molding in actual production.In order to study the deformation rules of fastener molding,this thesis studies the molding processes of titanium hexagonal head screws and high-temperature alloy bihexagonal head bolts by finite element simulation and experimental methods,analog simulation of the molding process has been carried out by using DEFORM-3D software and contrast experiment of grain size has been carried out.This research mainly analyzes the influence of different process parameters and different materials on the forming of fasteners by simulation.According to the analysis of finite element simulation: Through the analog simulation of the molding process of titanium hexagonal head screws,the change regulations of equivalent stress,equivalent strain are basically the same,the maximum value mostly appears at the upper surface and the central part of the lower surface of the screw head,and the minimum distributes on the outer surface of the screw,and with the increasing temperature and velocity,the equivalent stress and equivalent strain of the same parts decrease gradually,but the temperature field gradually increases.Through the analog simulation of the molding process of high-temperature alloy bihexagonal head bolts,the change regulations of equivalent strain,strain rate and damage are basically the same,the maximum value mostly appears at the edges of the angles of the bolt head,and with the gradual downsizing towards the two sides of the edges,the minimum mostly appears at the upper and lower surfaces of the bolt head.Single-factor experiment has been used,the height of bolt head has been set to be unchanged and the influence of different diameters on the stability of the molding process has been discussed to gain the conclusion that when the ratio of length and diameter of the blanks is below 7.20,distortion will not appear.The comparison between the results of the grain size experiment and the analog simulation shows that,the results are basically the same.