Papers by Keyword: Topological Optimisation

Abstract: The bracket-cable is one of the important structures of transmission control system of Heavy Commercial Vehicle. By using the compliance (strain energy) as an object function and the volume as constrain, the topology optimization design for the bracket-cable is performed with Hyperworks10.0, which is made considering the characteristics of structure, constraints and forces etc. To meet the structural strength and stiffness requirements, 34.7% of the mass are decreased after the process. The generalization designing method of the structure of the bracket is also provided. The Structure analysis and the topology optimization based on the finite element method may help us get the best variation of the design during the developing phase. It has also significance to shorten the design process and to improve the product quality.

Abstract: By triangle finite elements, grillages with stress constraints are optimized. From it an optimal beams systems or plate with reinforced ribs is obtained. A truss-like continuum material is adapted. The material distribution field in design domain is optimized by fully-stressed criterion. The densities and orientations of the beams or reinforced ribs at nodes in grillages are taken as design variables. These densities and orientations vary in design domain continuously. The optimal distribution fields of moments, deformation and material are obtained simultaneously. Subsequently the discrete structures are determined based on the optimal distribution fields. A very simple geometry matrix of triangle plate element is given. The stiffness matrix of truss-like continuum in triangle element is derived. The optimization iteration procedure is suggested. The optimization procedure is accomplished by computer program automatically.

Abstract: With the minimum mass of steel structure for bodywork as the object, beam sections and location topologies as design variables, and the stress and displacement as constraints, the optimum model is established. With the method of killing or activating elements, a high level technique in MSC. Marc, by Genetic Algorithms, a new scheme of researching structure topology optimization is proposed and the calculation procedure system is programmed. Applied the system, a steel structure of bodywork is optimized successfully. The validity and practicability of the system are certified.

Abstract: In this paper, according to the ICM (Independent Continuous Mapping) method, the topology optimization problem of continuum structures is solved. The topology optimization model for the continuum structure is constructed, which minimized weight as the objective function and was subjected to the buckling constraints. Based on the Taylor expansion, the filtering function and the Rayleigh quotient, the objective function and the buckling constraint are approximately expressed as the explicit function. The optimization model is translated into a dual programming and solved by the sequence second-order programming. Finally, the compressed bar examples are presented. They verified the length coefficient which is converted into stability bar hinged at both ends, identified the location of bottlenecks in topological structures. According to the results, more reasonable topological structures were given.

Abstract: Movable platen is key component of a plastic injection machine. In this paper the movable platen of HBT80X/1 plastic injection moulding machine is redesigned using topology optimization method. The SIMP method and OC method were applied as the optimization principle and Optimality Criteria. After given the topology structure, the refined structure is designed with experience. The results show that the weight and maximum placement of the new shape were 53Kg and 0.009mm less than the original design.

Abstract: In accordance with integral structure of woodworking machine tool (WMT), this paper uses the method based on topology optimization design to establish the objective function, constraints, and convergence Criteria. In the meantime, some related factors of woodworking machine tool (WMT), such as economical efficiency, stability, and dynamic properties are taken into consideration. Moreover, through analyzing an instance, the validity of design method has been demonstrated.

Abstract: This paper deals with the redesign of a machine tool substructure which reinforces the working table of a gantry type milling machine. The original design of the reinforcing structure is a grillage structure to strengthen the working table. In order to improve the design, the cutting edge technology of topology optimization is employed to redesign the reinforcing structure. The result obtained by topology optimization shows that the redesigned topology of the reinforced structure is totally different from that of the original design. With the same material used, the stiffness and the natural frequencies of the working table are much higher than the original design. Even with a less amount of material use, the stiffness and the natural frequencies are still improved significantly.

Abstract: It is well known that structural behaviors of composite solids are determined by topology of microstructures of different sizes. In this paper a concurrent topology optimization method for integrated design of materials and structures with periodical microstructure was presented. The microstructures were assumed to be uniform in macro scale and heterogeneous in micro scale and the optimization object was to maximize the material fundamental frequency. Design variables for structure and material microstructures were defined, independently. RAMP (Rational Approximation ofMaterial Properties) was adopted to ensure clear topologies in both macro and micro scales. Design variables for structure and material microstructures were integrated into one system by using the super-element method. Influences of Representative Volume Element sizes, the microstructure configuration and macro arrangement are investigated. Numerical experiments validate the proposed method which can be used as an innovative design concept for the lightweight structures.

Abstract: The purpose of this paper is to avoid the crack problem of the ceramic shell during the burnout procedure of the rapid investment casting using stereolithograghy (SLA) model. Since the coefficient of thermal expansion of the SLA model is much higher than the coefficient of the ceramic shell, the internal structural patterns have to be properly designed to reduce the stress level in the ceramic shell. A topology optimization method is proposed here to find better microstructure designs to satisfy both the strength of the ceramic shell and the stiffness of the SLA model itself. Taking the arrayed microstructure into account, the pseudo-densities of the SLA model elements to describe the material layout are defined and assumed as the design variables. By deriving the design sensitivities, the topology optimization problem is solved with reasonable numerical results generated.

Abstract: This paper proposes an improved computational algorithm for structure topology optimization. It integrates the merits of Evolutionary Structure Optimization and Level Set Method (LSM) for structure topology optimization. Traditional LSM algorithm has some drawbacks, for instance, its optimal topology configuration is largely dependent on the structural topology initialization. Additionally, new holes cannot be evolved within the updated topology during the optimization iteration. The method proposed in this paper combines the merits of ESO techniques with the LSM scheme, allowing new holes to be automatically inserted in regions with low deformation energy at prescribed iterations of the optimization. The nodal neighboring region is a good selection. For complex structures in which holes cannot be properly inserted in advance, the proposed method considerably improves the ability of LSM to search the optimal topology. In addition to achieving more accurate results, the proposed method also yields higher efficiency during optimization. Benchmark problems are presented to show the effectiveness and robustness of the new proposed algorithm.