Browsing by Author "Plaza, S."
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Item CT-based traceable interface area detection in Al7075-T6 adhesive bonded structures(euspen, 2022) Holgado, I.; Ortega, N.; Perez, B.; Florez, S.; Plaza, S.; Leach, Richard K.; Akrofi-Ayesu, A.; Nisbet, C.; Phillips, Dishi; POLIMEROSIn emerging technologies such as aerospace and aeronautics the joining of multi-material parts is a growing need for the development of components with improved properties. Among efficient joining technologies, adhesive bonding is considered an optimal method for joining multi-material structures, however, its use is limited due to inadequate evaluation of bond quality by non-destructive testing (NDT) methods. Recently, computed tomography (CT) is becoming more and more accepted in the non-destructive testing (NDT) community, thanks to the equipment and software development. This technology is capable of performing quantitative dimensional and geometric analysis, for example of adhesive bonds. Nevertheless, quantitative results obtained by CT are strongly influenced by a large number of error sources and thus the accuracy of CT-based measurements remains yet largely uncertain. In most cases a consistent methodology is needed, so that CT could be considered a reliable technology. This paper aims to evaluate the adhesive bonding quality in metal bonded structures by means of CT. To do so, a structural adhesives with four different Aluminum specimens are analyzed. The adhesives used are MERBENIT SF50® and BETAMATE 2810® and the substrates of Al7075-T6 of 3mm thickness. For each bonding configuration, a novel ML-based method for the detection of the contact area between adhesive and substrate is provided. Each adhesive interface area measurement is associated with its corresponding task-specific uncertainty estimation. Results are promising and useful for adhesive bond quality evaluations in CT equipment.Item Threading holder based on axial metal cylinder pins to reduce tap risk during reversion instant(2023-03-01) Fernández-Lucio, P.; Gil Del Val, A.; Plaza, S.; Pereira, O.; Fernández-Valdivielso, A.; López de Lacalle, L. N.; FABRIC_INTELInternal thread profiles are used widely in manufacturing processes with the aim of assembling/disassembling different components during maintenance activities from the aeronautics sector until common industrial parts. The threading process is one of the last operations carried out to obtain those components, and consequently, it is an operation of high added value. Threading is a complex operation that must carefully synchronize the rotation with the feed movements to avoid tool breakage during the instant of tapping reversion stage. In order to avoid this risk, several toolholders were developed present in the literature but deficiencies in terms of stability and productivity. Therefore, in this work, a new toolholder is proposed in which the common springs used to mitigate the lack of perfect synchronization between rotation and feed movements are replaced by elastic metal pins achieving a torsional compliance toolholder. The results show that the use of the proposed toolholder implies not only a productivity increase but also a surface integrity improvement as well as a stress reduction that the cutting tap is subjected and thus, achieving a substantial improvement in the current tapping processes. In particular, the use of the proposed toolholder implied a 75% reduction of the maximum stress achieved in the reversal instant, improving 20% tool life with an increase of 30% cutting speed. Therefore, the use of the proposed toolholder implies a substantial improvement in the current tapping processes.