Study On Bending Mechanical Properties Of High Strength Steel Sheets

Roll forming process is bent sheet metal gradually into a profile by several rollers.Sheet metal tensile test are often used for achieve the mechanical properties of materials,for which finite element simulation in roll forming process.The tensile mechanical properties can not accurately reflect the stress and strain status of sheet metal.In the finite element simulation of roll forming process,the choice of material's model is very important to get a good result which is matching the real test.In order to improve the accuracy of finite element simulation,a bending test was designed to obtain the DP980's stress and strain data in the bending deformation.Tensile tests were carried out to obtain the tensile properties of DP980 high strength steel.By using a specially designed bending test device,the longitudinal moving of the tensile test machine was converted to the bending deformation of the sample.The bending deformation process of the sample was measured by GOM ARAMIS device.The moment-curvature characteristics of DP980 high strength steel was converted to stress-strain data which is indicate the DP980's bending condition clearly.The finite element simulation model of three point bending and roll forming process was established.The forming characteristics of three point bending and roll forming process were analyzed by compared the stress-strain data in the bending corner and stress-strain data on the flat.The three point bending test and roll forming test of DP980 high strength steel plate were carried out and compared the result with the corresponding finite element simulation.The simulation of the bending model can predict the springback angle more accurately than tensile test model in the three point bending and roll forming process.