FLD on crack when there is no obvious necking produce these materials can not accurately predict the forming limit

With industrial development, and some new material produced, these materials are light weight, high strength, corrosion resistance and other advantages. To tensile instability or bifurcation  abrasive grinding  on the crack FLD no obvious necking when these materials are produced can not accurately predict the forming limit  cubic boron nitride  can not be based on well established FLD optimization objective function and  cutting tools  . While the actual production of many factors that affect the product quality, material properties and process parameters fluctuations, as well as precision molds such as noise reduction factors will lead to a decline in product quality. Sheet metal forming usually do not meet the crack, do not wrinkle as well as a small rebound, etc., using simple weighting method can not solve sheet metal forming multi-objective optimization problem.