Variational B-rep model analysis for direct modeling using geometric perturbation. Issue 4 (14th March 2019)

• Record Type: Journal Article
• Authors: Zou, Qiang; Feng, Hsi-Yung
• Is Part Of: Journal of computational design and engineering. Volume 6:Issue 4(2019)
• Page Start: 606
• Page End: 616
• Publication Date: 2019-03-14
• Subjects: CAD modeling -- Direct modeling -- Geometric constraint systems -- Constraint system characterization -- Constraint system analysis; Engineering -- Data processing -- Periodicals; Computer-aided design -- Periodicals; Computer-aided design; Engineering -- Data processing; Electronic journals; Electronic journals; Periodicals; 620.0042
• DOI: 10.1016/j.jcde.2019.03.002
• Languages: English
• ISSNs: 2288-4300

Abstract

Graphical abstract: Abstract: The very recent CAD paradigm of direct modeling gives rise to the need of processing 3D geometric constraint systems defined on boundary representation (B-rep) models. The major issue of processing such variational B-rep models (in the STEP format) is that free motions of a well-constrained model involve more than just rigid-body motions. The fundamental difficulty lies in having a systematic description of what pattern these free motions follow. This paper proposes a geometric perturbation method to study these free motions. This method is a generalization of the witness method, allowing it to directly deal with variational B-rep models represented by the STEP format. This generalization is essentially achieved by using a direct, geometric representation of the free motions, and then expressing the free motions in terms of composites of several basis motions. To demonstrate the effectiveness of the proposed method, a series of comparisons and case studies are presented.