8 documents found, page 1 of 1
Influence of corrosion on the electrical and mechanical performance of hybrid b...
Sampaio, Rui F. V.; Bragança, Ivo; Pragana, J. P. M; Silva, C. M. A.; Fernandes, João C. S.; Martins, Paulo A. F.This paper is focused on the electrical and mechanical performance of aluminum-copper hybrid busbars subjected to corrosion over time. Two different types of hybrid busbars with joints produced by conventional fastening with M8 hexagonal socket head bolt-nut pairs made from medium carbon steel and by a new injection lap riveting process with semi-tubular rivets made from the material of the softer conductor are...
Hybrid wire‑arc additive manufacturing of conformal cooling channels: a feasibi...
Pragana, João; Bragança, I. M. F; Silva, C. M. A.; Martins, P. A. F.This paper investigates the feasibility of hybridizing wire-arc additive manufacturing with metal forming to create conformal cooling channels in moulds for hot material processing. An axisymmetric mould is used as a prototype test case and plastic deformation by flaring of the additively deposited inner tubular element is utilized to create the overhangs for connecting with the outer tubular element that are n...
New self-clinching fasteners for electric conductive connections
Sampaio, Rui F. V.; Martins, Paulo; Pragana, J. P. M; Bragança, Ivo; Silva, C. M. A.This paper presents new rotational and longitudinal symmetric self-clinching fasteners to fabricate reliable connections in busbars with low electrical resistance for energy distribution systems. Connections consist of form-closed joints that are hidden inside regions where two busbars overlap. The investigation into the fabrication and performance of the new self-clinched joints involved finite element modelli...
Hybrid metal additive manufacturing: A state–of–the-art review
Pragana, J. P. M.; Sampaio, Rui F. V.; Bragança, Ivo; Silva, C. M. A.; Martins, P. A. F.This paper starts from the early developments and working principles of the additive manufacturing of polymers, continues with a glimpse on the extension to metals with identification and characterization of the two most widespread technologies, and ends with an overview of the recent developments in hybrid metal additive manufacturing. Earlier classifications of hybrid manufacturing with roots on the utilizati...
Invisible mechanical lap joints for metal–polymer laminates
Batista, R. J. S.; Bragança, I. M. F; Silva, C. M. A.; Pragana, J. P. M; Martins, P. A. F.Joining by compression of metallic inserts has been recently developed by the authors to create invisible lap joints between metal and polymer laminates. This paper revisits the process with the objective of proposing a new type of bi-material (polymer–metal) cylindrical insert for lightweight construction applications that is capable of ensuring complete filling of the joint at the end of stroke without increa...
Formability of a wire arc deposited aluminium alloy
Silva, C. M. A.; Bragança, Ivo; Cabrita, A.; Quintino, L.; Martins, P. A. F.This paper is focused on the formability of the aluminium alloy AA5083 deposited by wire arc additive manufacturing (WAAM). The presentation draws from metal deposition with a robotic welding system to mechanical and formability characterization by means of standard test specimens. Finite element analysis using porous metal plasticity is utilized to model strain hardening and the changes in porosity due to plas...
Joining of sheets by sheet-bulk forming: a numerical and experimental study
Bragança, Ivo; Loja, Amélia; Silva, C. M. A.; Alves, L. M.; Martins, P. A. F.The authors present a new mechanical joining process that allow to connect two sheets perpendicular to one another, a variant of the traditional ‘mortise-and-tenon’ joint. This investigation is focused on joining similar and dissimilar sheets based on sheet-bulk forming and it is supported by experimental data and numerical simulation with an in-house finite element program, I-form. Results show that is possibl...
Concentrations and species composition of atmospheric volatile organic compound...
Oliva, S. T.; Botelho, Maria de Lourdes; Silva, C. M. A.; Tavares, Tânia Mascarenhas; Kesselmeier, J.; Kuhn, U.; Rottenberger, S.; Biesenthal, T.Texto completo: acesso restrito. p. 1-13; Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2014-01-20T13:26:23Z No. of bitstreams: 1 S. T. Oliva.pdf: 814795 bytes, checksum: d4f6f77bb2a5411243189df225dc06a2 (MD5); Made available in DSpace on 2014-01-20T13:26:23Z (GMT). No. of bitstreams: 1 S. T. Oliva.pdf: 814795 bytes, checksum: d4f6f77bb2a5411243189df225dc06a2 (MD5) Previous issue date: 2002; We measur...