| In recent years,the rapid development of industrial technology,metal curved parts,especially aluminum alloy curved parts are widely used in aerospace,engineering and construction,automotive and shipbuilding and other industrial fields.Curved aluminum parts are often pressed through integral molds and can be processed in high volume production.However,as modern manufacturing technology is gradually changing from traditional high-volume production to small-lot,digital production,the shortcomings of long overall mold design cycles,high manufacturing and maintenance costs,and poor versatility are becoming more and more prominent,and cannot meet the increasing demand for curved aluminum alloy components with complex shape features and large dimensional differences.Therefore,multi-point forming technology stands out.As a fast and efficient flexible forming technology,multi-point forming enables the forming of various curved components with complex shape features and large dimensional differences by means of adjustable mold surfaces.Co MPared with traditional monolithic mold forming,multi-point forming technology saves time in mold design,reduces manufacturing and maintenance costs,and greatly improves production efficiency.Although multi-point forming technology has greater advantages than integral mold forming,the springback problem of curved components in the multi-point forming process still exists,and the application of segmented multi-point forming of large curved components is still relatively small,so how to carry out effective springback compensation and how to design reasonable segmented forming process parameters is the focus of this paper.For the multi-point forming process of corrosion-resistant aluminum alloy curved components,this paper investigates the springback compensation and segmentation process by combining finite element numerical simulation:(1)The basic principles and development process of multi-point forming are introduced,and the development of segmented multi-point forming,the current status of multi-point forming springback research,and the overview of multi-point forming numerical simulation are also outlined.(2)The sheet forming theory and finite element analysis theory were studied,and the selection of numerical simulation algorithm for finite element was discussed,which laid the theoretical foundation for the subsequent numerical simulation of multi-point forming.(3)In view of the problem of large springback during multi-point forming of curved components for new corrosion-resistant aluminum alloy ships,the springback compensation calculation formula and multi-point mold profile compensation method were studied.The springback compensation method was used to simulate the multi-point forming process of corrosion-resistant aluminum alloy curved components,and the springback of the curved components before and after the compensation was analyzed by co MParing four characteristic position contour lines from two variable curvature edges and two diagonal lines;A multi-point forming test was conducted,and a laser scanner was used to scan the test part to obtain the point cloud data to build a 3D model,and a comprehensive co MParison was made with the simulated part after springback compensation and the target part to check the forming accuracy.The results show that: The simulated and test parts after springback compensation almost match the target part shape,effectively compensating the large amount of springback in the multi-point forming process of corrosion-resistant aluminum alloy curved parts,and the error is significantly reduced,which better realizes the variable curvature characteristics of the target shape and meets the engineering requirements of marine parts,and provides a reference solution for the study of springback of curved parts and its compensation.(4)Numerical simulations were conducted to analyze the segmented multi-point forming process of large curved components of corrosion-resistant aluminum alloys,and the effects of six different transition zone length designs and coordinated designs of curvature with and without transition zones on the segmented multi-point forming results were investigated from three aspects of stress,strain and forming accuracy to obtain reasonable segmentation process parameters.The results show that: Reasonable design of the transition zone length can reduce the violent deformation generated during the segmented multi-point forming process,and ensure a certain level of forming quality and accuracy while taking into account the high production efficiency;The coordinated design of the transition zone curvature based on the reasonable design of the transition zone length can further improve the accuracy of the segmented multi-point forming boundary and suppress the generation of forming defects,thus improving the forming quality and accuracy of large curved components of corrosion-resistant aluminum alloys. |
