8 documents found, page 1 of 1
Effect of L‐T and S‐T orientations on fatigue crack growth in an aluminum 7050‐...
Borges, Micael F.; Antunes, Fernando V.; Jesus, Joel; Branco, Ricardo; Prates, Pedro; Neto, Diogo M.This study is focused on the anisotropic fatigue crack growth (FCG) behavior of an aluminum AA7050-T7451 plate. L-T and S-T orientations were studied in M(T) samples with W = 50 mm, in mode I loading, with R-ratio of +0.05. A numerical approach was used, assuming that crack tip plastic strain is the crack driving force. A purely kinematic elastic–plastic model was calibrated using experimental data from low cyc...
Effect of Residual Stresses on Fatigue Crack Growth: A Numerical Study Based on...
Neto, Diogo M.; Borges, Micael F.; Sérgio, Edmundo R.; Antunes, Fernando V.Residual stresses affect the fatigue behavior, given that compressive stresses delay the phenomenon, while tensile stresses accelerate it. However, the mechanisms behind the effect of residual stresses are not totally understood. A numerical study is developed here to understand the effect of thermal residual stresses (TRSs) on fatigue crack growth (FCG). The crack driving force was assumed to be the cumulative...
FCG Modelling Considering the Combined Effects of Cyclic Plastic Deformation an...
Sérgio, Edmundo R.; Antunes, Fernando V.; Borges, Micael F.; Neto, Diogo M.Fatigue is one of the most prevalent mechanisms of failure. Thus, the evaluation of the fatigue crack growth process is fundamental in engineering applications subjected to cyclic loads. The fatigue crack growth rate is usually accessed through the da/dN-ΔK curves, which have some well-known limitations. In this study a numerical model that uses the cyclic plastic strain at the crack tip to predict da/dN was co...
Numerical Prediction of the Fatigue Crack Growth Rate in SLM Ti-6Al-4V Based on...
Ferreira, Fábio; Neto, Diogo M.; Jesus, Joel S.; Prates, Pedro A.; Antunes, Fernando V.This study presents a numerical model to predict the fatigue crack growth (FCG) rate in compact tension specimens under constant amplitude cyclic loadings. The material studied is the Ti-6Al-4V titanium alloy produced by selective laser melting, which was submitted to two di erent post-treatments: (i) hot isostatic pressing, and (ii) heat treatment. The developed finite element model uses the cumulative plastic...
Revisiting Classical Issues of Fatigue Crack Growth Using a Non-Linear Approach
Borges, Micael F.; Neto, Diogo M.; Antunes, Fernando V.Fatigue crack growth (FCG) has been studied for decades; however, several aspects are still objects of controversy. The objective here is to discuss different issues, using a numerical approach based on crack tip plastic strain, assuming that FCG is driven by crack tip deformation. ΔK was found to control cyclic plastic deformation at the crack tip, while Kmax has no effect. Therefore, alternative mechanisms ar...
Numerical Study on the Variability of Plastic CTOD
Prates, Pedro André; Marques, Armando Eusébio; Borges, Micael Frias; Branco, Ricardo Madeira; Antunes, Fernando V.This paper presents a numerical study on the influence of material parameters and loading variability in the plastic crack tip opening displacement (CTOD) results. For this purpose, AA7050-T6 was selected as reference material and a middle-cracked tension specimen geometry was considered. The studied input parameters were the Young's modulus, Poisson's ratio, isotropic and kinematic hardening parameters and the...
Multiaxial Fatigue Life Prediction on S355 Structural and Offshore Steel Using ...
Cruces, Alejandro; Lopez-Crespo, Pablo; Moreno, Belen; Antunes, Fernando V.This work analyses the prediction capabilities of a recently developed critical plane model, called the SKS method. The study uses multiaxial fatigue data for S355-J2G3 steel, with in-phase and 90 out-of-phase sinusoidal axial-torsional straining in both the low cycle fatigue and high cycle fatigue ranges. The SKS damage parameter includes the effect of hardening, mean shear stress and the interaction between s...
Monotonic and Cyclic Behavior of DIN 34CrNiMo6 Tempered Alloy Steel
Branco, Ricardo; Costa, José D. M.; Antunes, Fernando V.; Perdigão, SandraThis paper aims at studying the monotonic and cyclic plastic deformation behavior of DIN 34CrNiMo6 high strength steel. Monotonic and low-cycle fatigue tests are conducted in ambient air, at room temperature, using standard 8-mm diameter specimens. The former tests are carried out under position control with constant displacement rate. The latter are performed under fully-reversed strain-controlled conditions, ...