Analysis And Research Of Defects In Stamping Process Of Thin-walled Components

The sheet metal stamping technology is a commonly used manufacturing process for producing thin-walled metal parts.Typically,a metal sheet is placed on a stamping press,and then processed into the desired shape using a punch.In the automotive and military industries,the stamping of thin metal sheets is particularly important.The conventional method of repeated stamping and trial dies is a commonly used production process,but it has significant disadvantages,such as inability to guarantee product quality,as well as increased research and development cycles and costs.With the continuous development of computer finite element analysis technology,sheet metal forming technology has gained more development and opportunities.Sheet metal forming CAE software can predict various forming defects that may occur,analyze the causes of forming defects,optimize the sheet metal forming process,and improve production efficiency and product quality.The research focuses on the armor plate component of a certain model of tank manufactured by a weapon processing factory in Xi’an,China.The material of the armor plate is 5182 aluminum alloy,and the main defect observed after the actual stamping process is wrinkling.To address this issue,three-dimensional modeling of the sample parts was conducted,and they were imported into AUTOFORM for numerical simulation analysis of the stamping process,with the variable being the thickness of the sheet metal.Based on the wrinkling distribution map,maximum failure map,forming limit diagram,forming window diagram,and thinning ratio map,it was determined that the sheet metal thickness does not affect the occurrence of tearing defects after the stamping process but only affects the occurrence of wrinkling defects.Furthermore,considering the relevant literature,it was found that factors affecting the occurrence of wrinkling defects in sheet metal stamping also include the magnitude of the edge pressure and the friction coefficient.Therefore,the relationship between sheet metal thickness,edge pressure magnitude,and friction coefficient was investigated to explore the wrinkling defect in the stamping process.In order to investigate the relationship between the distribution of wrinkling defects in5182 aluminum alloy sheet after stamping and the numerical values of sheet metal thickness,edge pressure magnitude,and friction coefficient,an orthogonal experiment was designed to examine the interactions among sheet metal thickness,edge pressure,and friction coefficient.The experimental parameters were then inputted into the AUTOFORM software for numerical simulation calculations.Based on the results of the numerical simulations,it was found that thinner sheet metal,lower edge pressure magnitude,and higher friction coefficient were more likely to lead to wrinkling phenomena.Subsequently,numerical simulation experiments were conducted again based on this characteristic,and three parameter combinations were obtained that almost did not result in wrinkling defects.These three sets of parameters were then imported into MATLAB for multivariate linear regression analysis,establishing a mathematical relationship model between the optimal sheet metal thickness,edge pressure magnitude,friction coefficient values,and the absence of wrinkling defects in 5182 aluminum alloy sheet after stamping.To validate the reliability and practicality of this mathematical model,numerical simulation experiments and actual stamping engineering tests were conducted on tank outer armor plates,and the results of the engineering tests were consistent with the numerical simulation results,both meeting the production requirements of the product.