64 documents found, page 1 of 7
A novel hydraulic bulge test in hot forming conditions
Boyer, A.; Demazel, N.; Coër, J.; Carin, M.; Laurent, H.; Oliveira, M. C.A novel hydraulic bulge test device was developed to evaluate high temperature biaxial stress–strain curves of quenchable boron steel sheets. The work mainly focuses on the resistance heating designed to assure a homogeneous temperature field in the dome area of the circular blank where the hydraulic pressure will be applied. The practical hot stamping conditions, including the heating and cooling steps, were r...
Sensitivity analysis of the of the square cup stamping process using a polynomi...
Pereira, A. F. G.; Marques, A. E.; Oliveira, M. C.; Prates, P. A.The stochastic modelling and quantification of the various sources of uncertainty associated with sheet metal forming processes, usually requires a large computational cost to obtain accurate results. In this work, a polynomial chaos expansion metamodel is used in order to reduce the computational cost of the uncertainty quantification (through Sobol’s indices). The metamodel allows to establish mathematical re...
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...
CONSIDERACOES SOBRE A RAMESCENCIA DA AORTA ABDOMINAL DO HAMSTER DOURADO (MESOCR...
Orsi, A. M.; Pinto Silva, E. P.; Mello Dias, S.; Oliveira, M. C.Made available in DSpace on 2022-04-29T08:41:56Z (GMT). No. of bitstreams: 0 Previous issue date: 1975-01-01; Dept. Morfol., Fac. Ci. Med. Biol., Botucatu
HISTOLOGIE REGIONALE DE L'EPIDIDYME CHEZ L'OPOSSUM SUD AMERICAIN. ETUDE DE MICR...
Orsi, A. M.; Ferreira, A. L.; De Melo, V. R.; Oliveira, M. C.Made available in DSpace on 2022-04-29T08:42:13Z (GMT). No. of bitstreams: 0 Previous issue date: 1981-01-01; Dept. Morphol., Inst. Biol. Botucatu, Univ. 'Julio de Mesquita Filho', Botucatu
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...
Influence of the orthotropic behaviour on defects prediction in cup drawing, re...
Oliveira, M. C.; Neto, D. M.; Alves, J. L.; Menezes, L. F.Finite elements analysis is commonly used in the cans tool design since it allows predicting different sheet metal defects and instabilities that significantly affect the efficient production of beverage cans. These defects include caring, due to the material orthotropic behaviour, thinning and fracture. The numerical prediction of these kind of defects is more complex when different combinations of strain path...
Numerical analysis of the bulge test in temperature for the EN AW 6061-T6 sheet
Boyer, A.; Germain, L.; Laurent, H.; Neto, D. M.; Oliveira, M. C.The equibiaxial expansion test allows the evaluation of the mechanical behaviour of materials on a large strain range. In this context, a bulge test device was developed which enables a fast heating stage, a uniform heating of the specimen, and the control of the temperature during the expansion phase. Although during the test, the temperature is uniform at the pole of the cap, the contact with the tools impose...
Experimental and numerical analysis of the heat generated by plastic deformatio...
Neto, D. M.; Simoes, V. M.; Oliveira, M. C.; Alves, J. L.; Laurent, H.; Oudriss, A.; Menezes, L. F.This study evaluates the temperature variation observed in quasi-static uniaxial tensile tests, due to the heat generated by plastic deformation. The AA6016-T4 aluminium alloy was the material selected, considering different values of crosshead velocity (from 0.01 mm/s up to 1 mm/s). The temperature variation was also evaluated during the stress relaxation test. A finite element model of the uniaxial tensile te...
Study on the influence of the yield surface shape in the hole expansion test
Oliveira, M. C.; Neto, D. M.; Alves, J. L.; Menezes, L. F.The hole expansion test has become popular since it allows to study the formability of metallic sheets, in particular the onset of necking in stretch flanging areas. The accurate prediction of strain localization and consequent fracture requires a proper description of the plastic behavior, particularly the anisotropic yield function. In the context of strain localization prediction, the yield criterion adopted...