Papers by Keyword: Topological Optimisation

Abstract: From recent studies on natural composites such as nacre and bone, it has shown that the mechanical properties of the composite are significantly affected by the Poisson’s ratio of each constituent phase. In some cases it is found that when the Poisson’s ratio approaches the incompressibility limit, the stiffness of the composite in one or more directions can increase dramatically, in some cases by two or more orders of magnitude than the softer phase. In this paper we investigate designing the composite of maximum stiffness by a topology optimisation approach. The method used is based on the bi-directional evolutionary structural optimisation (BESO). The Optimisation problem is formulated and it is solved by a searching algorithm based on the sensitivity analysis. The effect of interpolation function in the sensitivity analysis is studied. Examples of different combinations of Poisson’s ratios are presented. The stiffness is found to increase from its base value. In the case of one phase having negative Poisson’s ratio, the increase is very significant. It is concluded that the proposed method is effective in optimising the stiffness of this class of composite.

Abstract: DVG850 high-speed machining center worktable is taken as research object, in order to meet the overall performance requirements of the high-speed machining center, 3D model of worktable is established in SolidWorks. Static analysis and modal analysis are carried out in ANSYS Workbench, and then the worktable is optimized in topology optimization module of ANSYS Workbench. According with the analysis results, the worktable structure has improved. The improved worktable keeps the original’s static performance, and enhances the dynamic performance; however, its quality is lighter than original structure by 23.2 kg.

Abstract: This research introduces a multidomain topology optimization algorithm for crashworthy structure undergoing large deformations. This technique makes use of the hybrid cellular automaton framework, which combines transient, non-linear finite-element analysis and local control rules acting on cells. The set of all cells defines the multidomains. Each subdomain has been defined by different material update rules according to specify constraint, and optimization iteration of each subdomain has been converged respectively during the optimal design process. The effectiveness of this technique is demonstrated through the design of a bumper-like structure. Result show that the new algorithm is suitable for practical applications. The case study presented demonstrates the potential significance of this work for a wide range of engineering design problems.

Abstract: In order to improve the riveting precision, the finite element method and topological optimization design based on the variable density method were employed to design the pedestal of horizontal rocket rivet fixture. Topological optimization model was set up based on static analysis of the original designed pedestal under various typical load cases. Topological optimization results of various load cases were compared with original pedestal. The result showed deficiencies of the original pedestal, and a new model was built based on topological optimization results. The analysis of topological model was carried out by applying the finite element method. The results show that the stiffness of pedestal was remarkably improved; the stress distribution was more homogenized and the displacement of the guide rail was decreased after optimization. This method could also provide reference and guidance for designing other complicated structures.

Abstract: In order to study the effect of tire operating mode on its safety performance, a high-speed tire test-bed was put forward. The dynamic characteristic of drum was important for test result. To avoid the resonance of loaded drum during operation, the topological optimization analysis of drum with I-shaped structure was fulfilled with the element density as variables and the volume reduction of fifty percent as constraint condition and the first natural frequency as objective function. The optimal density distribution of drum was obtained within the constraint of the first natural frequency. Based on the analysis result of topology optimization, the drum structure with I–shaped was modified. The structure size of the new and improved drum was optimized with 50 iterative calculations using ANSYS. On the condition that the first natural frequency of drum was over 60Hz, the structure size of drum was optimal when the rate of the first natural frequency and total weight was highest and equaled to 0.05391. The optimization results showed the first natural frequency of drum was raised by 21.972Hz and its total weight was reduced by 69.95Kg.

Abstract: In order to ensure that each node is connected with one another in P2P network and strengthen the invulnerability of network topology, in this paper, topological optimization in unstructured P2P network was studied. Based on the weakest part in network---topologically-critical node, existing algorithm to search and eliminate topologically-critical nodes was analyzed and improved. The experiment results show that the improved CAM algorithm (ECAM algorithm) can greatly reduce the network consumption and communication costs and improve discovery efficiency while ensuring the discovery accuracy.

Abstract: The paper is concerned with topology optimization in the mechanical design process. The disadvantage of current process of mechanical design is discussed and a new design process based on structural topology optimization is presented. The design process with structural topology optimization in mechanical design is discussed by the example of the frame of a bender. Static analysis is made to the original model first according to the whole structure and working characteristic of the machine, the stress and deformation distribution are obtained and then topology optimization is carried out. On the basis of topology optimization, the layout of the initial design proposal is obtained and the weight of the frame is substantially reduced while the performance enhanced. The application of the method demonstrates that through innovative utilization of the topology optimization techniques, the conceptual proposals can be obtained and the overall mechanical design process can be improved substantially in a cost effective manner.

Abstract: One kind of multi-void three-dimensional microstructure models based on homogenization method is constructed. Based on multi-void microstructure, the mathematical models for the topological structural optimization which takes maximizing the total potential energy as the objective function is constructed, then the Kuhn-Tucker optimality condition of the update method about the designs variable based on the porous microstructure can be gotten when optimization iterates. Finally, in explaining the employed algorithm an example is provided.

Abstract: When designing implantable biomedical MEMS devices, we must provide electric power source with long life and small size to drive the sensors and actuators work. Obviously, traditional battery is not a good choice because of its large size, limited lifetime and finite power storage. Living creatures all have non-electric energy sources, like mechanical energy from heart beat and pulse. Piezoelectric structure can convert mechanical energy to electric energy. In the same design condition, the more electric energy is generated, the better the piezoelectric structure design. This paper discusses the topology optimization method for the most efficient implantable piezoelectric energy harvesting device. Finally, a design example based on the proposed method is given and the result is discussed.

Abstract: In this paper, the stress and strain of the tracked triangle wheel’s original basic frame which is used on shovel loader were analyzed in AnsysWorkbench. And topological optimization method was then used to optimize the basic frame so as to find out its best bearing structure, after which the original basic frame was improved and designed for the second time in the solidworks environment. And then, the stress and strain of the basic frame’s new structure were analyzed again. In the end, a comparison was carried out between the finite element analyze results before and after the topological optimization. According to the comparison, the weight of the basic frame is reduced by 22.5% while the stress and strain nearly keep the same.