No abstract

No abstract

Modeling the dimensional variation propagation in multi-station machining processes (MMPs) has been studied intensively in the past decade to understand and reduce the variation of product quality characteristics. Among others, the Stream-of-Variation (SoV) model has been successfully applied in a variety of applications, such as fault diagnosis, process planning and processoriented tolerancing. However, current SoV model is limited to the MMPs where only fixtures with punctual locators are applied. Other types of fixtures, such as those based on locating surfaces, have not been investigated yet. In this paper, the derivation of SoV model is extended to model the effect of fixture-and datum-induced variations when fixtures with locating surfaces are applied. Due to the hyperstatic nature of these fixtures, different workholding configurations can be adopted. This will increase the dimension of the SoV model exponentially and thus, may make the model-based part quality prediction extremely complex. This paper presents how to reduce the complexity of the SoV model when fixtures based on locating surfaces are applied and how to evaluate the worst-case approach of the resulting part quality. Key Product Characteristic.Mathematical symbols for SoV model A k−1 : Matrix thatrepresentshowthevariations aretransmittedby datum features generated before station k. Matrix defined by matricesandM a t r i xt h a tr e p r e s e n t sh o wfi x t u r ea n dm a c h i n i n gd e v i a t i o n s affect part quality at station k. Matrix defined by matrices B f k and B m k .M a t r i xt h a tr e p r e s e n t sh o wt h ed e v i a t i o n so fp a r ts u r f a c e sare related to the deviations of KPCs inspected after station k. u k :F i x t u r ea n dm a c h i n i n gd e v i a t i o n sa ts t a t i o nk.M e a s u r e m e n tn o i s eo ft h ei n s pe c t i o np r o c e s sa f t e rs t a t i o nk.U n -m od e l e ds y s t e mn o i s ea n dl i n e a r i z a t i o ne r r o r sa ts t a t i on k.D i m e n s i o n a ld e v i a t i o n so fp a r ts u r f a c e sa ts t a t i o nk. y k :D e v i a t i o n so ft h eK P C si n s pe c t e da f t e rs t a t i o nk.

Registro de acceso restringido Este recurso no está disponible en acceso abierto por política de la editorial. No obstante, se puede acceder al texto completo desde la Universitat Jaume I o si el usuario cuenta con suscripción. Registre d'accés restringit Aquest recurs no està disponible en accés obert per política de l'editorial. No obstant això, es pot accedir al text complet des de la Universitat Jaume I o si l'usuari compta amb subscripció. Restricted access item This item isn't open access because of publisher's policy. The full--text version is only available from Jaume I University or if the user has a running suscription to the publisher's contents.

No abstract