86 documents found, page 1 of 9
Considering the stiffness of the forming tools in the numerical analysis of the...
Oliveira, Marta C.; Neto, Diogo M.; Alves, J. L.; Menezes, Luís F.Ironing can occur in cylindrical cup drawing whenever the thickness of the drawn flange is larger than the gap between the punch and the die. This is particularly relevant for materials that present r-values lower than 1.0, such as the aluminium alloys, since they tend to present more thickening of the flange. The aim of this study is to evaluate numerically the impact of the elastic deformation of the forming ...
Shielding AZ91D-1%Ca from corrosion through ultrasound melt treatment: a study ...
Gomes, Inês Varela; Pacheco, Ana Margarida Ribeiro; Nienaber, M.; Neves, Sara Carvalheira; Mei, D.; Barros, Alexandre António Antunes; Reis, R. L.Magnesium-based materials show great potential for producing biodegradable stents, but their high corrosion rates are a roadblock. This study investigates whether ultrasound melt treatment can change the corrosion response of an extruded AZ91D-1.0%Ca (wt.%) in Earle's Balanced Salt Solution by tailoring the intermetallics' morphology in the as-extruded state. The results showed that the wires from ultrasound-tr...
Ultrasound-assisted casting of AZ91D-1.5%Ca – Shifting T4 paradigm for downstre...
Gomes, Inês Varela; D'Errico, F.; Alves, J. L.; Puga, HélderThe effect of the as-cast microstructure on solution treatment of AZ91D-1.5%Ca was investigated. Ultrasound treatment was applied during the casted alloy's cooling, promoting the refinement of alpha-Mg and /9-Mg17Al12 phases. Fine and divorced /9-phase was found in the ultrasound-treated sample, resulting in a superior dissolution rate of this intermetallic during subsequent solution treatment. The results indi...
Influence of the anisotropic behavior on equibiaxial paths
Salles, F. F.; Oliveira, M. C.; Neto, D. M.; Alves, J. L.; Menezes, L. F.; Fernandes, J. V.Marciniak and Nakajima tests are commonly used in building FLD's, since they allow covering all regions from uniaxial to almost equibiaxial strain paths. In this work, the deviation from equibiaxial strain paths is analyzed as function of the material anisotropic behavior. The numerical results show that material with r0 = r90 present equibiaxial stress and strain paths, while for the ones with r0 ≠ r90 the pat...
Investigating the plastic anisotropy and hardening behavior of a commercial Zn–...
Cauvin, Ludovic; Raghavan, Balaji; Jin, Jianqiang; Bouvier, Salima; Wang, Xiaodong; Meraghni, Fodil; Alves, J. L.The aim of this work is to conduct a comprehensive examination of the anisotropic plastic behavior of a sheet of commercial Zn-Cu-Ti alloy, undergoing different quasi-static deformation paths at room temperature. Various mechanical tests are performed, including uniaxial and bi-axial tensile tests, Meuwissen and shear tests, obtaining homogeneous and heterogeneous strain fields. It was observed that under monot...
Professor Pimenta Claro (1957-2018): Pioneer in dynamics of mechanical systems ...
Flores, Paulo; Alves, J. L.; Dourado, N.; Marques, FilipeThis work highlights the importance of Professor Pimenta Claro in the genesis and development of a new scientific area at the Department of Mechanical Engineering of the University of Minho, namely Dynamics of Mechanical Systems. Professor Pimenta Claro initiated his academic career in October 1980, coming from industry, where he was a well-recognized engineer in the field of mechanical design. Professor Piment...
Assessing the accuracy of different remapping methods in adaptive mesh refinement
Marques, B. M.; Neto, D. M.; Alves, J. L.Additive manufacturing of metals has attracted much attention over the last years, promoting the development of several computational models for numerical simulation of the laser powder bed fusion (LPBF) process. Nevertheless, the finite element analysis of the LPBF process requires a large computational time. Thus, adaptive mesh refinement strategies are commonly adopted to reduce computational cost, which req...
Analysis of ESAFORM 2021 cup drawing benchmark of an Al alloy, critical factors...
Habraken, Anne Marie; Aksen, Toros Arda; Alves, J. L.; Amaral, Rui L.; Betaieb, Ehssen; Chandola, Nitin; Corallo, Luca; Cruz, Daniel J.This article details the ESAFORM Benchmark 2021. The deep drawing cup of a 1 mm thick, AA 6016-T4 sheet with a strong cube texture was simulated by 11 teams relying on phenomenological or crystal plasticity approaches, using commercial or self-developed Finite Element (FE) codes, with solid, continuum or classical shell elements and different contact models. The material characterization (tensile tests, biaxial...
On the effect of the tension-compression ratio on forming of isotropic materials
Oliveira, Marta C.; Prcela, Ivan; Cvitanić, Vedrana; Neto, Diogo M.; Alves, J. L.; Menezes, Luís F.It is generally believed that the choice of the yield criterion used to describe the plastic behaviour of isotropic metallic materials does not affect much the accuracy of the predictions of forming operations. For this reason, the von Mises yield criterion is widely used for modelling their plastic behaviour. However, according to the von Mises yield criterion, the ratio between the yield stresses in tension a...
Study on the influence of the strain rate sensitivity on the springback of the ...
Neto, D. M.; Oliveira, M. C.; Alves, J. L.; Menezes, L. F.Warm forming processes have been successfully applied to overcome some important drawbacks of the aluminium alloys, such as poor formability and large springback. The virtual try-out of this type of processes requires the accurate prediction of springback. The process conditions considered in this work are the ones established for the benchmark 3 - Springback of an Al-Mg alloy in warm forming conditions, propos...