Research On Dimension Constraint Processing Method And Structural Optimization Technique For Rapid Variant Design Of Automatic Lid Opening And Closing Device

Rapid variant design(RVD) technology is widely used in various industries because it can improve the efficiency and quality of product design, shorten development period and put product on market quickly to promote enterprise benefit and enhance enterprise strength. Taking automatic lid opening and closing device as the research object, dimension constraint processing method, topology optimization technique and dimension optimization technique of RVD technology are studied deeply and systematically in this thesis.Dimension constraint processing is key factor for realizing RVD. Traditional dimension constraint processing method removes redundant dimension constraint by design experience only and cannot optimize the transfer process. Utilizing the ability betweenness centrality method measures nodes importance of complex network, dimension betweenness centrality model is established based on dividing function modules and formulating dimension constraint grades and strategies. Establishing analysis model for dimension complexity, dimension constraint relation modules are divided. Dimension constraint transfer direction is determined based on dimension constraint grade of parts and assembly relation among parts, and then dimension constraint processing flow is established. Aiming at Pro/E, a transfer method for dimension constraint of multi-grade parts is proposed, combining with secondary developing program of Pro/E, RVD of automatic lid opening and closing device is realized.Topology optimization is key technique for ensuring RVD object to obtain the ideal structure form. Deficiencies of evolutionary structural optimization(ESO) method on element deletion and numerical error processing are analyzed based on case, and then bi-directional evolutionary structural optimization(BESO) method which can realize element addition and deletion is improved. Weighting sensitivity of nodes within the range of filtration radius of element centroid as element sensitivity, homogenization processing of element sensitivity based on strain energy criterion is realized. Addition and deletion criteria of element, constraint conditions and convergence criterion are defined, and then the improved BESO method flow is established. Superiority of BESO method is proved based on case comparison, BESO of rotating platform of automatic lid opening and closing device is realized and 3D model of rotating platform is reconstructed.The improvement of RVD result can be realized by dimension optimization. Making static analysis and modal analysis, maximum deformation and natural frequency of rotating platform under static condition are extracted. First order optimization method is used to realize single-objective dimension optimization for stiffness and frequency of rotating platform. Linear weighted superposition method is used to establish multi-objective dimension optimization model and tolerance method is used to determine weight coefficient of subgoal. Programming by APDL language, multi-objective dimension optimization for stiffness and frequency is realized. Dimension optimization technique is integrated into RVD system based on secondary development technology of Pro/E and ANSYS, multi-objective dimension optimization of rotating platform is realized in RVD process of automatic lid opening and closing device, product design efficiency is improved and product quality is ensured at the same time.