CAE-Companion-2018-2019

Engineering WISSEN CAE

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Figure 7: Topology and shape optimization of a control arm (images courtesy OTTO FUCHS KG)

Workflow Structural Optimization supports the product development process in all stages at different level of detail. The goal is to start the development process using a start design which is already optimized regarding stiffness, weight etc. In the progress of the design process with continuously more accurate knowledge of boundary conditions and interaction parameters more and more detail improvements are required. For the full effect of structural optimization in the develop- ment process, the following procedure for simulation driven design could be followed: „ „ Define finite element model of maximum design space of component with all known loads and boundary conditions „ „ Perform topology optimization under consideration of manufacturing process „ „ Evaluate result „ „ Optional: Perform shape optimization based on validation model to remove local hotspots in design proposal „ „ Transfer validated result proposal into CAD and start detailed design „ „ Improve mature design by local changes through shape optimization „ „ Transfer modified shape into CAD to derive final design

Manufacturing Restrictions To ensure the functionality and manufacturability of the designed component the full flexibility of the optimization has to be restricted. In general, topology optimization may come up with very organic structures which cannot be produced at reasonable cost and effort. The result of shape or bead optimization may be a complex free form surface with severe undercuts etc. which may not be producible or easy-to-process in a CAD system. Thus external constraints require additional restrictions to the optimization task to: „ „ avoid the change of border areas to other components „ „ ensure the ability to manufacture the component „ „ control the design and look of the part. These restrictions can be formulated as: „ „ casting, drilling, stamping,… conditions „ „ member size control „ „ displacement restrictions „ „ frozen or fixed areas (to ensure connection to adjacent components) „ „ symmetry (rotational, planar, …) conditions „ „ general coupling conditions (pattern repetition, cyclic symmetry, …)

CAEWissen by courtesy of Dassault Systèmes - www.3ds.com/tosca

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