CADmodelsacasestudy.PDF

INT. J. COMPUTER INTEGRATED MANUFACTURING, JUNE 2004, VOL . 17, NO. 4, 352–363 Measurement-based updating of turbine blade CAD models: a case study MIHAILO RISTIC, DJORDJE BRUJIC and IAIN AINSWORTH Abstract. Manufacturing industries, especially the aerospace dedicated specialist teams who are responsible for and the automotive, require updating of CAD models so that specific aspects of engineering design, in-service per- the manufactured geometry is accurately represented. Often, additional constraints such as continuity are imposed on the formance and manufacturing process development model. The updated model may be employed to provide a (Pahk et al. 1995). There is a continuing need to realize more realistic analysis of the part’s in-service performance. a higher level of integration between these activities The necessary tools for realizing this task included dimen- (figure 1) in order to reduce the number of design sional measurement and geometric modelling. This paper iterations, minimize the need for experimental testing discussed how this was achieved in the case of an aeroengine gas turbine blade. Measurement was performed using a and on that basis to reduce the overall development coordinate measuring machine equipped with a touch trigger timescales and costs. probe. Measurement path plan is based on the pre-processed In the case of high-performance, free-form compo- CAD model. The accuracy was improved using our method nents such as aeroengine compressors and turbine for probe radius compensation. The re-modelling steps blades, it is generally difficult to relate the in-service include preparation of the base surface, registration and l