Rodrigo Rossi

Interference-Fit Joining of Aluminium Tubes by Electromagnetic Forming

Interference-fit joining of tubes by electromagnetic forming is an innovative and environmental friendly technology that can successfully replace conventional joining technologies based on fasteners, structural adhesives, welding and brazing. The technology works at room temperature, allows joining dissimilar materials and offers potential to foster new applications in the assembly of lightweight tubular frame structures. As with all new technologies, there is a need to understand interference-fit joining of tubes by electromagnetic forming in terms of its major parameters with the aim of identifying their influence on the overall strength of the joints and establishing the useful range of process operating conditions. This article investigates the interference-fit joining of aluminum-alloy tubes (AA6082-O) with mandrels made from different metallic and polymeric materials (AA6082-O, AISI1045 and Erlaton 6SA). Results show that the strength of the joint and the associated failure mechanisms are directly related to process parameters and materials.

An Analysis of Electromagnetic Sheet Metal Forming Process

Electromagnetic forming (EMF) is a high-speed forming process that uses energy density of a pulsed magnetic field to deform metallic workpieces. This paper presents a method to calculate the electromagnetic force in thin flat plates using a flat spiral coil as an actuator. The method is based on the Biot-Savart law, and the solution of magnetic induction integral equations is performed inside Matlab® by a numerical method based on discretizing the EMF system in a system of ordinary differential equations that couple the electric and magnetic phenomena. Free bulging experiments and a comparison with Ansoft Maxwell® software are presented demonstrating a good correlation with the proposed implementation.

Enrichment of a rational polynomial family of shape functions with regularity Ck0, k=0,2,4…

Purpose – The purpose of this paper is to investigate the approximation performance of a family of piecewise rational polynomial shape functions, which are enriched by a set of monomials of order p to obtain high order approximations. To numerically demonstrate the features of the enriched approximation some examples on the mechanical elastic response and free‐vibration of axisymmetric plates and shells are carried out.Design/methodology/approach – The global approximation is based on a particular family of weight function, which is defined on the parametric domain of the element, ξ∈[−1,1], resulting in shape functions with compact support, which have regularity C0k,k=0,2,4… in the global domain Σ. The PU shape functions are enriched by a set of monomials of order p to obtain high order approximation spaces.Findings – Based on the numerical results of elastic axisymmetric plates and shells, it is demonstrated that the proposed methodology produces satisfactory results in terms of keeping the ill‐condition...