Currently, the development of the market shows an increasing global competitive pressure, growing quality requirements and decreasing product cycle lifetime. Consequently, companies face demands for shorter development times and and shorter time between product idea and market launch. Thus, the application of appropriate CA-tools is mandatory. Component costs are largely taken into account early in the design process. Therefore, it should be aimed at approaching optimum design in the course of component optimization. How far a component is to be optimized depends on the general requirements. Again, the cost/benefit ratio should still be reasonable.
Topology optimization means distributing the available mass within a defined space so that a determined target function reaches it’s extremum. In practice, topology optimization is being applied throughout the design process in order to obtain proposals for the initial design of components. Here, the design enigineer has to primarily think about the maximum space and the boundary conditions (stresses and restraints). These data will be implemented into an FE-model (FE = Finite Element). In topology optimization, often the volume reduction of the FE-model is being demanded, so that it’s rigidity is maximal. Maximization of rigidity is equivalent to minimization of the entire strain energy.
As in topology optimization material has to be removed from the model to be optimized, rigidity of the single finite elements (FEs) has to be changed, so that it can be considered as a design variable. Elements, which have to be “deleted” have zero stiffness and zero density. Supporting elements have the maximum, material-dependent stiffness and density. Within a topoplogy optimization, the elements’ stiffness is being changed as long as the required volume and weight reduction is achieved and the entire strain energie is minimal.
Design of experiments (DoE) is applied in product and process development and optimization and can also be used for component optimization with the FE method. With DoE, influencing factors and interactions on the dependent variable are determined while minimizing of the number of tests. Thus, also the size of effects is being determined allowing an optimization of the processes to be analyzed. Evaluation takes place by using diagrams on main influential factors, interaction and Pareto diagrams, for the individual parameters and their combination. Subsequently, further optimization can be realized with the main influential factors.
Behaviour Modelling creates and calculates stochastic parameter combinations with optimization parameters and assorts them according to the required optimum. This can include several thousand automated calculations, for which only certain parameters are analyzed in a tabular form. By sorting the results, regions can be determined where specified targets are optimal.
Design optimization is a process based on the FE-method for the design of technical components. The purpose of design optimization is to better adapt the form of a component to the technical requirements, e.g. it can help to minimize material consumption at the given benefit. On the other hand, technical benefit can be maximized at the given materials usage. Environment gives many examples of design optimization, evolution provides for a slow, but continuous optimization of form and function. With trees, we can observe design optimization in just one generation. Due to outside influences, such as static load by wind, the tree changes it’s outer shape, thus minimizing stresses in it’s trunk. Bone remodeling around implants is another example, it is also based on biomechanical principles. In design optimization, these observations are transferred to a technical model. Optimization starts with a rough design proposal with known mounting, stress and given limit dimensions. This object is being modeled for the Finite-Element-Method and then the corresponding stress curve is being determined. By means of the adequate software material is virtually reduced at non-stressed areas of the component, or material is added at heavily stressed points respectively. After a certain number of iterations, a design-optimized component develops.
Beads are groove-like depressions or elevations in plane or curved sheet metal surfaces, whereby depth in relation to length is little. Beads increase flexural rigidity of sheets while weakening longitudinal rigidity. They are a popular method for the bracing of sheets but often effects are difficult to predict. With bead optimization, beads can optimally be designed, so that required properties of a sheet metal structure can be set.
© 2020 MERKLE & PARTNER GbR – All rights reserved.