Establishing And Updating The Parameterized Models Of The Flexible Roll Forming Process

Flexible digital forming technology of three-dimension curved surface parts isone of hot points in the flexible automation equipment researches. It can meet thepersonalized needs of diverse products and frequent modification with high versatilityand flexibility. As a result, it is being widely used in the aerospace, transportation,building decoration and other fields. Dieless forming technology center of JilinUniversity proposed a new flexible continues rolling forming method creatively,based on theoretical basis of rolling, roll extrusion and multi-point adjustment control,which is a flexible and efficient processing method for three-dimension curvedsurface sheet parts.This paper mainly introduces basic principle of flexible rolling forming,establishes parameterized finite element model according to theoretical analysis andderivate result. Then do some research on forming precision of flexible rollingforming and various factors’ influence on it and proposes rolling gap correction modelto improve the forming precision. At last, develop the special flexible rollingnumerical simulation module secondarily based on parameterized finite elementmodel and rolling gap correction model.1.The flexible rolling forming proposition and basic principleCompare the traditional rolling and uneven depression bend forming with theflexible rolling forming on the rolling gap distribution pattern. Propose that flexiblerolling forming is the extension of traditional rolling and uneven depression bendforming. Then analyze surface formation mechanism and do some theoretical andnumerical analysis mechanical condition and rolling pressure distribution in theprocess of flexible rolling forming. With the adjustment characteristics and applications of flexible rolling forming，propose two different adjustment projects andanalyze the possible defects in the process.2.Numerical analysis and parametric modeling of the flexible rollingformingEstablish calculation model for rolling gap distribution and working rollercontour curve of flexible rolling forming with plastic mechanics and mathematicalmethod. Establish the finite element parameterization model on the condition thatmake working roller contour curve calculation model as the calculation kernel,working roller dispersed a finite number of rigid rollers and model parameters andprocess parameters variable.Later on, take shape convex surface and saddle surface parts to verify numericalsimulation analysis and prove the reasonability of parameterization model.3. precision analysis of the flexible rolling formingPropose evaluation methodology of precision analysis of the flexible rollingforming through the analysis of flexible rolling forming defects and deviation. Findout that the longitudinal curvature radius deviation is the main forming deviation andregular interaction exists between the longitudinal and transverse curvature radiuswith the analyses of deviation distribution and interaction of the longitudinal andlateral curvature radius. Analyze the influence of all sorts of model factors andtechnological factors on longitudinal curvature radius and deviation, which providesthe basis for the subsequent error correction and compensation.4. The establishment of the rolling gap correction model and validationBy using the theory of single point secant method, establish two kinds of rollinggap correction model based on strain and rolling gap error aiming at the typicalconvex surface and saddle surface parts. Then analyze the convergence of correctionmodel. Making use of rolling gap correction model and numerical simulation analysis,find out that high precision longitudinal curvature radius is obtained through the stepsup to2, which verifies the rationality and effectiveness of the rolling gap correctionmodel.5. The secondary development of the special numerical simulation module Combined with the parameterized model and rolling gap correction model of theflexible rolling forming, develop the flexible rolling forming special numericalsimulation module based on Python language and Abaqus.this module not only makesmodels rapidly, but also completes rolling gap correction and improves the accuracyof numerical simulation with rolling gap correction model.