Study On Stretch Bending Forming Simulation And Accuracy Control Of Profiles

With the continued development of global economic integration and theincreasingly fierce market competition, facing the challenge of foreign advancedproducts, The national manufacturing industry need improve the accuracy ofmanufacturing，shorten the developing cycle，cut the manufacturing cost. As a processof considerable importance for plastic bending, stretch bending forming is widely usedin railway, automobile and aircraft manufacturing. Normally the profile which isproduced by Stretch bending forming often has high accuracy. So the traditional,experimental test method is not enough to guide the forming process of profile withcomplex section. At present, using CAD/CAE to guide production, study the stretchbending formability of profiles with different sizes, choose the reasonable formingparameters to improve the accuracy of manufacturing become the focus of stud y onstretch bending forming.This article gives a description to the basic principle of stretch bending and theloading and control process of the bending methods. Stretch Bending Forming with theloading condition of PMP is analyzed in theory: According to stretch-bendingcharacteristics, study on the stretch-bending process and springback mechanism of twotypes profiles separately which include small radius of curvature and large radius ofcurvature. Based on the bilinear harden constitutive model，The theoretical analysismodel is established to study sectional stress distribution and bending springbackexpression about two types of profiles.According to the theory, this article does research on L-section profiles ofaluminum alloy, establishes the finite element model of stretch bending forming in the Stretch-wrap bending machine based on the simulation software of ABAQUS. Theinfluence rules of the geometrical parameters and forming parameters on the crosssection distortion and springback in the stretch bending is analyzed separately.This article takes the subway door pillar for example, simulates its stretch bendforming process and studies the forming reasons of defects. By optimizing the formingprocess parameters, the contour precision of products is improved and the article offerssome guidance for the actual production. In addition, the aluminum alloy profilebending elongation should not be too large. Otherwise, the spring-back would exceedthe standards. Based on the theory of spring-back compensation, the outer contour ofdie is modified by using the technology of CAD/CAE. the simulated result showsspring-back is decreased. The rationality of optimized method is tested and verified byexperiments.