Applying virtual reality techniques to engineering design optimization

Virtual reality (VR) provides a new paradigm that links a human operator with a computer-generated environment via visual, audio, or haptic interaction to support the illusion of immersion. The objective of this dissertation is to explore the use of VR techniques for sensitivity-based structural shape design optimization. The design tool developed in this research allows the designer to alter the shape of the computer representation of a model and see the resulting changes to the deformation and stress displayed immediately in the virtual environment. The combination of using natural motions to alter computer models and the ability to view stereo images of these models in a three dimensional virtual space allows the designer to interactively examine design changes and determine their effects on product performance.; NURBS-based free form deformation (NFFD) and direct manipulation techniques are the methods implemented which allow the designer to change the shape of the design model, and also provide the information for the sensitivity computation in order to approximate the structural responses in real time. The designer-weighted optimization is also incorporated in the virtual environment which provides an additional capability to perform trade-off design for resolving conflicting design constraints.; A general purpose structural shape design program is developed to perform the structural shape design optimization in the virtual environment. Several examples demonstrate the advantages of this program.