Development Of Intelligent Design System For 3D Laser Cutting Trajectory Of High-Strength Steel

High strength steel body structural parts can meet the lightweight requirements of vehicles while ensuring the safety of vehicle collision.The strength of high-strength steel body structural parts usually reaches 1500 MPa.If the traditional die trimming and die punching are adopted,the die should have high strength,high wear resistance and high reliability,otherwise the die will be seriously worn when it reaches a certain number of working times.Three dimensional laser cutting is an advanced material cutting technology,which has the characteristics of high precision,fast cutting speed and small heat affected zone A.when cutting the body structural parts,it is only affected by the melting point of the body structural parts and not by the strength of the body structural parts.The current three-dimensional laser cutting NC programming system only considers the efficiency of three-dimensional laser cutting and ignores the impact of the rebound of body structural parts on the accuracy of three-dimensional laser cutting.Therefore,it is of great significance to realize the localization of threedimensional laser cutting trajectory intelligent design system considering threedimensional laser cutting efficiency and cutting quality.UG has excellent surface processing ability and provides users with rich secondary development interfaces.Therefore,the intelligent system for 3D laser cutting trajectory of high-strength steel is developed based on UG platform.The specific contents are as follows:(1)Off line programming module design.The development requirements,system architecture and development tools of the off-line programming module of 3D laser cutting are analyzed.Ug12 and Visio studio2017 are finally selected as the secondary development platform.The overall architecture of the off-line programming module of3 D laser cutting is introduced,with emphasis on the extraction and classification of 3D laser cutting trajectory of body structural parts,the discretization of cutting contour and the compilation of geometric macro instructions of internal contour,The generation of NC code is introduced.(2)Application of off-line programming module in three-dimensional five axis laser cutting machine tool.Through the NC machining code generated by the off-line programming module,the three-dimensional laser cutting test of a column of highstrength steel body structure of a vehicle is carried out,which verifies the practicability of the off-line programming module of three-dimensional laser cutting.The results show that the body structure has rebound after three-dimensional laser cutting,and the contour accuracy of the body structure is poor.The causes of springback are briefly analyzed.(3)In order to reduce the influence of springback defect on cutting accuracy in three-dimensional laser cutting of high-strength steel body structure,its springback characteristics were studied.Taking the A-pillar of a high-strength steel body structure of a vehicle as the research object,the finite element models of hot stamping and laser cutting are established respectively by using the finite element simulation software Auto Form and ABAQUS.The rebound value distribution diagram is obtained through numerical simulation,and the rebound law of the contour of the body structure after cutting is found.Secondly,the contour is compensated according to the direct compensation method based on rebound prediction to determine the best cutting contour,Finally,the semi-finished products of A-pillar stamping are verified by cutting test.The experimental results show that the proposed compensation method can control the contour error within the tolerance range,which verifies the effectiveness of the compensation method.