Computer-aided Engineering Process Research Articles

Automatic Detection of Geometric Features in CAD models by Characteristics

ABSTRACTIn this paper, we detailed a novel 3D detection method for geometric features in CAD models used in CAD-to-CAE model simplification process. Model preparation is now the most time consuming part in the computer-aided engineering process chain, it is commonly labor intensive. Therefore, the overall objectives are: 1) introduce automation to speed-up the model preparation process; 2) remove redundant features to reduce model mesh size for fast mesh generation and analysis without compromising on solution accuracy. Automatic feature detection that is generic and easily extendable is a key element needed to achieve these objectives. Inside the article, we proposed detection by characteristics to complement existing geometric modeling kernels for CAD systems with defeaturing functions to detect features previously not detectable.

Structural durability design optimisation and its reliability assessment

Mechanical fatigue subject to external and inertia transient loads in the service life of mechanical systems often leads to structural failure due to accumulated damage. A structural durability analysis that predicts the fatigue life of mechanical components subject to dynamic stresses and strains is a computer-intensive, multidisciplinary simulation process, since it requires the integration of several computer-aided engineering tools and large amounts of data communication and computation. Uncertainties in geometric dimensions result in the indeterministic fatigue life of a mechanical component. Uncertainty propagation to structural fatigue under transient dynamic loading is not only numerically complicated but also extremely expensive. It is, therefore, a challenge to develop a durability-based design-optimisation process and reliability analysis to ascertain whether the optimal design is reliable. The objective of this paper is to develop an integrated CAD-based computer-aided engineering process to effectively carry out design optimisation for structural durability, yielding a manufacturable, durable, and cost-effective product. In addition, a reliability analysis is executed to assess the reliability of the deterministic optimal design.

Technology 1991: software

Noteworthy software developments during 1990 are recounted. Amid rapid change, the overall direction seems clear: an ongoing battle among personal computer operating systems, the rise of object-oriented programming (OOP), the spread of computer-aided software engineering (CASE), and the proliferation of frameworks. In the area of operating systems, there are three strong candidates from which to choose-OSF/1, Unix System V Release 4, and DOS with Windows 3.0-and a fourth whose future is not yet clear-OS/2. Meanwhile, the major computer companies have lined up behind OOP, an approach that views a program as being built of objects composed of data and processes, with a child object inheriting characteristics from parent objects: the CASE market is growing far faster than business in the rest of the software industry, and the push is on for standard frameworks that provide multiplatform, multivendor support across the entire computer-aided engineering process