Dynamic Analysis And Optimization For Differential Based On Rigid-Flex Theory

Due to the strong development of economic globalization, trade liberalization andsocial information, many domestic companies continue to promote their products intoautomation and serialization. Therefore, the focus work of the entire manufacturing sectoris to develop high-quality and low-cost products in the short term. Obviously, theinefficient traditional design and manufacturing technology do not meet the requirementsof the modern era automobile manufacturing, so there is an urgent need for a new designconcept and development model.As the development of vehicle design toward lightweight, the flexible deformation ofdifferential components impact on the kinematics and compliance of differential should notbeignored. If differential components were treated as rigid body, the accuracy requirementswillnot be received. It is necessary to study the flexible deformation of components impacton differential dynamic characteristics.Firstly, based on modal analysis and combined the three-dimensional model ofdifferential, the modal test and finite element modal analysis for differential case are done.By the compartion of the first sixth vibration and vibrational frequency of differential case,it is found that each vibration modes are almost the same, and vibration frequency error isabout5%. It verifies the accuracy of the differential case model.Secondly, this thesis introduces the basic theories related to the finite element and thespecific steps of finite element analysis.At the same time, based on the method of finiteelement analysis, the Hypermesh software is taken as the pre-processing software, todivide the finite element mesh; after a satisfactory inspection of the mesh quality, it is thenimported into ANSYS/Workbench to have loading and constraints so as to carry out finiteelement analysis. According to the results of stress and strain for differential case indifferent working condition, the differential case meets the design requirements.Thirdly, when the stress and strain of differential case meets the design requirements,the important influence of the average stress on the fatigue life which is described in thefatigue theory should be grasped, then the thesis deals with the introduction of the nominalstress method, the fatigue life analysis of the differential case, and the safety factor of thedesigned differential case is got; according to the topology optimization theory, thelightweight design of differential case is done by using the topology optimization, after theresults-copmpartion with the design requirements of corporate; in order to verify whether the optimizaed differential case meets the actual requirements, the static analysis andfatigue analysis are done, and the results show the optimizaed model is accurate andapplicable.At last, based on ADAMS software, the rigid body dynamics simulation of differentialgear mechanism is carried on by taking full advantage of the theory of rigid body dynamicssimulation, it simulates the working condition of car driving straight into turning, thedynamics performance curves of gear in this course of the campaign are obtained, itverifies the working principle of the differential. Under the guidance of the theory ofmulti-body system dynamics, the flexible body model of planetary gear is built, based onthe ADAMS software to generate flexible body function, so as to built the rigid-flexiblecoupling model of the differential gear mechanism, and rigid-flexible coupling analysis ofit is carried on. By analyzing the stress cloud and the maximum stress of10nodes offlexible body, it is found that the gears of differential meet the design requirements. Itprovides technical support for the design of gear.