Encontrados 14 documentos, a visualizar página 1 de 2
Numerical study of contact forces for crack closure analysis
Antunes, F. V.; Chegini, A. G.; Correia, L.; Branco, R.Plasticity induced crack closure (PICC) has been widely studied using numerical models. Different numerical parameters can be considered to quantify the opening level, namely one based on the analysis of contact stresses at minimum load. A modified version of this parameter is proposed here, based on nodal contact forces instead of contact stresses. The predictions were found to be similar to those obtained fro...
A parameter for quantitative analysis of plasticity induced crack closure
Antunes, F. V.; Correia, L.; Ramalho, A. L.Numerical models have been successfully developed to predict plasticity induced crack closure (PICC). However, despite the large research effort a full understanding of the links between physical parameters, residual plastic wake and PICC has not been achieved yet. The plastic extension of material behind crack tip, Δyp, obtained by the integration of vertical plastic deformation perpendicularly to crack flank,...
Plasticity induced crack closure: a sensitivity analysis
Correia, L.; Antunes, F. V.; Ramalho, A. L.Plasticity induced crack closure (PICC) is closely linked to the monotonic and reversed plastic deformation occurring at the crack tip. The objective of the paper is to identify the different physical and numerical parameters affecting PICC, and develop a sensitivity analysis to quantify their relative importance. The main parameters affecting PICC are the load parameters, the yield stress, the size of finite e...
Finite element simulation of plasticity induced crack closure with different ma...
Rodrigues, D. M.; Antunes, F. V.http://www.sciencedirect.com/science/article/B6V2R-4VJBTT1-2/2/2d6e310ec9d19271801c42837b91ee0d
Finite element modelling and analysis of crack shape evolution in mode-I fatigu...
Branco, R.; Antunes, F. V.A numerical procedure was employed to study the shape evolution of fatigue cracks in Middle Cracked Tension specimens. This iterative procedure consists of a 3D finite element analysis to obtain the displacement field in the cracked body, calculation of stress intensity factors along crack front and definition of local crack advances considering the Paris law. Numerical predictions were compared with experiment...
Numerical simulation of plasticity induced crack closure: Identification and di...
Antunes, F. V.; Rodrigues, D. M.Numerical studies play a major role in the understanding and prediction of plasticity induced crack closure (PICC). However, the available numerical models can be considered simplifications of reality as they consider discrete crack propagations, relatively high fatigue crack growth rates (FCGR), sharp cracks, and propagation occurring at well-defined loads. Besides, there are a great number of numerical and ph...
Determination of Paris law constants with a reverse engineering technique
Branco, R.; Antunes, F. V.; Martins Ferreira, J. A.; Silva, J. M.Paris law constants are commonly obtained with a well established procedure based on standard specimens, notched and pre-cracked. Pre-cracking produces through cracks with stable shapes, nearly straight, similar during all propagation. However, in several situations specimens with corner and surface cracks are recommended. In these cases cracks having significant propagation will continuously modify their shape...
A study on the mechanical behaviour of WC/Co hardmetals
Ferreira, J. A. M.; Amaral, M. A. Pina; Antunes, F. V.; Costa, J. D. M.The hardmetal cutting tools used in machining are submitted to extreme conditions in terms of temperature and mechanical loading. A better understanding of the failure of cutting tools and capability to predict tool life are key factors in the development of new tool materials with improved mechanical behaviour. Main failure mechanisms are wear, thermal-mechanical fatigue and brittle fracture. The aim of presen...
Fatigue crack growth in heat-treated aluminium alloys
Borrego, L. P.; Costa, J. M.; Antunes, F. V.; Ferreira, J. M.http://www.sciencedirect.com/science/article/B6V2X-4V42JDW-1/2/7483d2e761bf28c40a5ae2c39c720313
Flexural behaviour of hybrid laminated composites
Reis, P. N. B.; Ferreira, J. A. M.; Antunes, F. V.; Costa, J. D. M.The present paper studies the flexural behaviour of hand manufactured hybrid laminated composites with a hemp natural fibre/polypropylene core and two glass fibres/polypropylene surface layers at each side of the specimen. When compared with full glass fibres reinforced polypropylene laminates, the hybrid composites have economical, ecological and recycling advantages and also specific fatigue strength benefits...
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