2026-10-14T05:57:23Z https://api.figshare.com/v2/oai

oai:figshare.com:article/32805332 2026-10-01T16:16:28Z portal_1172 item_type_8 month_year_10_2026

Modelling variational geometry in computer-aided design for tolerance aware product development Imelda Friel (24292631) PUREID: 672746216 This thesis describes the development of means by which the Digital Mock-up (DMU) can better inform decisions related to tolerance design concurrently with functional part design.<br><br>The lack of CAD capabilities to represent ‘as manufactured’ products means design evolves with limited consideration of the effects of dimensional variation. These effects are analysed statistically using computer-aided tolerancing software, but at late stage design when changes can be time consuming and costly. There is currently no opportunity for the designer using CAD software to model and analyse dimensional variation during preliminary design to better inform decisions relating to manufacturing.<br><br>This work identified the need to provide the capabilities to model dimensional variation of parts within CAD enriching design from a manufacturing perspective. This work has developed and presented a methodology to successfully model and integrate variational geometries alongside their nominal parts in an assembly within the CAD environment, propagating dimensional change along the assembly to visualise and understand its ultimate effect. The methodology has been implemented in CATIA V5 using Python through a win32com wrap-around. Analysis of the enriched DMU has been demonstrated on three product models of varying complexity with different investigative purposes, including tolerance analysis. Results show how the enriched DMU can serve to inform the designer about the impact of design/manufacturing decisions and their effect on tolerance stack-ups.<br><br>The methods presented here fulfil the current gap between statistical analysis as tool for tolerance verification after design and the lack of variation modelling techniques in CAD to advise the tolerance design process at the earliest opportunity in product design. 2026-10-01T16:16:28Z Text Thesis 10.17034/32805332.v1 https://figshare.com/articles/thesis/Modelling_variational_geometry_in_computer-aided_design_for_tolerance_aware_product_development/32805332 All Rights Reserved