Research Of Adaptive Growth Technology In Structural Topology Optimization

The development of science and technology asks for more and more requirementsof the performance of structures. It is a common goal of designers that developing ascientific and efficient design method to solve the problem of structural design. Incontrast to the traditional and empirical structural design method, structural designoptimization based on the theory of mathematical optimization and the accurate finiteelement analysis can obtain a better design with a more simple process. In the area ofstructural design optimization, topology optimization is regarded as the mostchallenging research topics. In contrast with the shape optimization and sizeoptimization, topology optimization has a largest design area to find the optimal designwhich can make a maximum improvement in the performance of structures. On theother hand, the design result of the topology optimization will effect the furtheroptimization such as shape optimization or size optimization. Thus, topologyoptimization is a research hotspot in area of structural design optimization in recentyears.As a type of topology design optimization method, the bionic based adaptivegrowth technology is derived from the mechanism of growth and branching of thenatural branching system, which can automatically distribute the material on structure inaccording with the boundary condition. The design process of the adaptive growthtechnology is flexible and can be carried easily. Some key points of the adaptive growthtechnology used to obtain the optimal layout design of stiffeners for stiffened plate orshell structures are studied such as construction of ground structures, the influence ofthe value of the parameters in algorithm to design results, and the automatic seedselection technology. In contrast with the current adaptive growth technology, themodifications of the modified adaptive growth technology include the limitation of theheight of stiffeners in according with the reality of engineering, constructing arelationship between the width and height of the stiffeners to ensure the accuracy ofmodeling the stiffeners with beam elements in the growing process of stiffeners, and theintroduction of a stable index and a degeneration index to increase the computationalefficiency. The eccentric arrangement of stiffeners and layout design of some typicalsection type stiffener is studied, and a further optimization strategy the size optimizationof the stiffeners is suggested based on the result of the stiffener layout design. Based on all the conclusions of the above research, the layout design of stiffeners for plate or shellstructures based on adaptive growth technology is applied on an actual engineeringstructural design to obtain the optimal layout design of stiffeners for automobile enginehood. The result shows that the stiffness of the optimal design of automobile enginehood obtained by adaptive growth technology is increased29.41%with the11.11%decrease in its weight in contrast with the current design.On the basis of maximum stiffness structural design, the design theory of theadaptive growth technology is extended in the layout design of stiffeners for plate orshell structures to improve the buckling stability of the stiffened plate or shell structures,design of truss to improve the global stiffness of the structure, and the layout design ofstiffener plates for box formation. The results of typical design examples show that theadaptive growth technology is suitable in the three extended design area mention above.