Def@ShapeCAT: Consideration of part deformations in shape-aware computer-aided tolerancing

• Applicant: Professor Dr.-Ing. Benjamin Schleich
• Subject Area: Engineering Design, Machine Elements, Product Development
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 469126611

As a consequence of inevitable manufacturing imprecisions, geometrical deviations are observed on every manufactured part. Tolerance analysis provides a quantitative tool that enables the assessment of the effects of these geometrical part deviations on the function of mechanical assemblies. It is widely used in design to support the functional specification of tolerances, but also in the pre-production and production stages to support process planning activities, the tolerance verification, the root cause analysis, and the manufacturing and assembly process optimization. Due to this importance, various tolerance analysis theories and methods have been proposed in scientific literature within the last decades. However, they all share severe intrinsic limitations. As a response to this, a comprehensive framework for the shape-aware tolerance analysis based on Skin Model Shapes has been developed recently, which overcomes important weaknesses of established tolerance analysis approaches, such as the lacking conformance to international tolerancing standards and the missing consideration of form deviations. However, up to now, this existing tolerance analysis framework is limited to the assessment of the effects of geometrical deviations on rigid parts, while it is acknowledged, that these deviations add up with further deviations caused by physical phenomena, such as thermal expansion and part deformations. To overcome this shortcoming, this project aims at elaborating new approaches and methods for the consideration of part deformations in the tolerance analysis based on Skin Model Shapes. Particularly, new methods for the consideration of structural and local part deformations and their interrelationships with geometrical part deviations in the tolerance analysis will be explored. The elaborated procedures and algorithms will also be implemented in a prototype application for the tolerance analysis based on Skin Model Shapes to demonstrate the applicability of the developed methods. In summary, the planned project will hence strongly contribute to the growing demand for more sophisticated computer-aided tolerancing tools and considerably broaden the scientific body of knowledge regarding tolerancing theories.

• DFG Programme: Research Grants