6 documents found, page 1 of 1
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...
Load sequence effects and cyclic deformation behaviour of 7075-T651 aluminium a...
Branco, R.; Costa, J. D.; Prates, P. A.; Berto, F.; Pereira, C.; Mateus, A.This paper investigates the effect of loading history on cyclic deformation and fatigue behaviour of 7075-T651 aluminium alloy subjected to two-step loading. High-low and low-high sequences, encompassing both symmetrical and asymmetrical steps, are performed under strain-controlled mode for different loading scenarios. An elastic-plastic constitutive model is developed using the finite element method to simulat...
Influence of the mesh size on plastic CTOD
Sanchez-Mancera, J.; Camas, D.; Prates, P. A.; Antunes, F. V.The fatigue crack growth rate is experimentally correlated to the applied range of stress intensity factor, ΔK. However, the crack growth is taking place in an area where there are significant plastic deformations. At the same time, ΔK is an elastic parameter that cannot predict the influence of the load stress ratios and load history. Elastic-Plastic Fracture Mechanics parameters such as the energy release rat...
Notch fatigue analysis and crack initiation life estimation of maraging steel f...
Branco, R.; Prates, P. A.; Costa, J. D.; Ferreira, J. A. Martins; Capela, C.; Berto, F.This paper deals with the notch fatigue behaviour and crack initiation life estimation in maraging steel fabricated by laser beam powder bed fusion under multiaxial loading. Tests are conducted in tubular geometries with lateral holes considering different normal stress to shear stress ratios and multiaxial loading levels. The cyclic stress–strain response at the notch-controlled process zone is simulated numer...
A Numerical Study of the Effect of Isotropic Hardening Parameters on Mode I Fat...
Borges, Micael Frias; Antunes, F. V.; Prates, P. A.; Branco, R.The consideration of plastic crack tip opening displacement (CTOD, p), as a crack driving force has given us the opportunity to predict fatigue crack growth (FCG) rate numerically, and, therefore, to develop parametric studies focused on the e ect of loading, geometrical, and material parameters. The objective here is to study the e ect of the isotropic hardening parameters of the Voce law on FCG, which are the...
Analytical sensitivity matrix for the inverse identification of hardening param...
Prates, P. A.; Pereira, A.F.G.; Oliveira, M.C.; Fernandes, J.V.