Design Frame Based On The Method Named "the Minimum Division"

The existing skeleton frames were formed with a large amount of welded joints which mustbring a lot of defects.These defects directly influence the structure of frame and the vehiclemovement stability, safety and dynamic performance.In the design stage,the performance offrames can be improved and enhanced by improving the mechanical properties.It is necessary toachieve the minimum connection when the strength and stiffness was guaranteed in order toimprove the performance of the frame, avoid too much connection and reduce the erroraccumulation.This paper proposed the method of frame design named “minimum segmentation” toachieve the minimum connection.The method is that design the frame with the ideas of overall,then the overall frame was segmentated in the right location of the small stress area because ofthe restrictions of processing,assembling and manufacturing level,link the regionals atlast.However, in order to avoid too many connections, reduce the error accumulation, minimumsegmentation must be guaranteed under the condition of the enough strength and stiffness toachieve the balance of the design and manufacture.In this paper,two new frame design methodwere proposed to realize minimum segmentation of frame design,because the structure designand mechanical analysis were Organically combined to become a design process and thecomputer’s power and excellent function of auxiliary software were combined.One is nameddesign skeleton frame based on the method of removal of areas with small stresses,the other isnamed design frame based on topological optimization with the multiple condition modes.Inboth methods, structure design and function design and optimization were achieved according to the result of performance analysis of frame.The frame designed by these method has theadvantages of optimalizing performance, structure&function, and less time-consuming.This paper puts forward a kind of methods of " subtracting areas with small stress ". Byparametric design with using ANSYS software, skeleton frame was divided into some systemmodule spaces contact with skeleton frame. Get the stress distribution of whole skeleton frame,cut off the small stress areas and then conduct another strength analysis. More than onceiteration calculations and resections were needed in order to satisfy the require of strength andstiffness， as well as minimum quality. Finally adopt minimum division according tomanufacturing and assembly technology to get high performance steel skeleton frame structure.Segmentation points were distributed at the small stress areas to avoid the accumulated error, inorder to improve the overall characteristics of the vehicle.Topological optimization with the multiple condition modes is a kind of conceptual design:on the premise of unknown structure topological shape, according to known boundaryconditions and loading conditions to determine a reasonable structure.Structure of frame wasdesigned and optimized by starting with the performance of the frame and using ANSYSfunction of topology optimization with multiple working conditions expressed with loadingmodes and constraint modes.Performance design was operated to integrated abstract model offrame by topology optimization in static bending working mode as well as braking workingmode. Resect small density areas according to the pseudo density profile and get the preliminarystructure model of frame. Mechanical performances of frame were analyzed in three differentworking modes,improved continually, finally the reasonable structure model and function modelwere obtained. Control natural frequency and lightweight design in the condition of sufficientstrength&stiffness to improve the overall performance of the frame as well as save material.Segmentation points were distributed at the small stress areas to avoid the accumulated error, inorder to improve the overall characteristics of the vehicle.The manufacturing methods of unit frame were discussed simply at the end of this article.