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Abstract: |
A tolerance modeling method of geometric variations within three-dimensional (3D) tolerance domain is proposed.According to the classification method of feature variations and classes of invariance or symmetry in the new generation Geometrical Product Specifications (GPS) system, the proposed method is based on the Small Displacement Torsor (SDT) concept, and SDT is used to represent the geometric deviations between the nominal feature and the fitting feature. Furthermore, the variation zones of several kinds complex or irregular geometric features are constructed, and the corresponding tolerance modeling methods are discussed respectively. Finally, an example is presented to verify the efficiency of the presented method for modeling 3D dimensional and geometrical tolerances.The proposed modeling method based on the complete mathematical foundation conforms with the design philosophy and principle of the new generation GPS standards system. |
Key words: geometrical product specifications (GPS) tolerance modeling feature geometric variations small displacements torsor (SDT) |
DOI:10.11916/j.issn.1005-9113.16147 |
Clc Number:TH124 |
Document Code::A |
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Descriptions in Chinese: |
三维公差域内几何特征变动的建模方法 彭和平1,卢文龙2 (1.江汉大学 机电与建筑工程学院,武汉 430056; 2.华中科技大学 机械科学与工程学院,武汉 430074) 创新点说明:提出一种复杂特征几何变化的三维公差建模方法。根据新一代产品几何技术规范(GPS)中几何特征的定义和特征变动的分类法,所提出的建模方法基于小位移旋量(SDT)的概念,SDT参数用于建模拟合特征相对于名义特征的几何偏差变动。进一步构造了几种复杂或不规则几何特征的变动区域,讨论了相应的三维公差建模方法。最后,通过数值实例验证了该方法对三维尺寸公差和几何公差建模的有效性。完全基于数学基础提出的建模方法符合现行的GPS标准体系的思想。 研究目的: 本文提出并建立各种复杂非规则几何特征变动的定量化数学模型,开发了集成几何公差在内三维公差建模方法,为进一步研究三维公差分析和设计奠定理论基础,是新一代GPS与现有公差设计理论相结合的学术研究前沿。 研究方法和结论: 基于理论上的探讨,采用实例分析验证方法的有效性。 关键词:产品几何技术规范(GPS);公差建模;特征;几何变动;小位移旋量(SDT) |