Encontrados 13 documentos, a visualizar página 1 de 2
Impact strength of composites with nano-enhanced resin after fire exposure
Reis, P. N. B.; Ferreira, J. A. M.; Zhang, Z. Y.; Benameur, T.; Richardson, M. O. W.Composite materials have been widely used in several engineering applications. However, there are very few studies about the effects of nanoclays on the impact strength of laminates after exposure to the fire. Therefore, this paper intends to study this subject and the impact performance was analysed by low velocity impact tests carried out at different incident impact energy levels. For better dispersion and i...
Residual stresses analysis in plasma dressed welded joints
Ramalho, A. L.; Ferreira, J. A. M.; Branco, C. M.The presence of residual stresses in a structure influences his behaviour. Fatigue strength of welded joints is significantly influenced by the presence of residual stresses, of flaws and notch sharpness at the weld toe. Plasma dressing at the weld toe is frequently used to remove flaws and to lessen the notch sharpness at the weld toe. With this re-melt, the stress field in the weld toe is also profoundly modi...
Fatigue Behaviour of T Welded Joints Rehabilitated by Tungsten Inert Gas and Pl...
Ramalho, A.; Ferreira, J. A. M.; Branco, C. M.This paper concerns a fatigue study on the effect of tungsten inert gas (TIG) and plasma dressing in non-load-carrying fillet welds of structural steel with medium strength. The fatigue tests were performed in three point bending at the main plate under constant amplitude loading, with a stress ratio of R = 0.05 and a frequency of 7 Hz. Fatigue results are presented in the form of nominal stress range versus f...
Fatigue life evaluation for carbon/epoxy laminate composites under constant and...
Reis, P. N. B.; Ferreira, J. A. M.; Costa, J. D. M.; Richardson, M. O. W.http://www.sciencedirect.com/science/article/B6TWT-4TN82M4-1/2/ffb1a17eaf7390463ad097c3ba5d4e8f
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...
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...
Influence of superposition length on mechanical resistance of single-lap adhesi...
Reis, P. N. B.; Antunes, F. J. V.; Ferreira, J. A. M.The present work studies the mechanical behaviour of single-lap joints of PP reinforced with glass fibres. Failure loads were obtained experimentally for different superposition lengths (15, 30, 45 and 60 mm). A 2D numerical analysis was developed using the finite element method, and assuming a plane strain state, an orthotropic behaviour for the laminates and an elastic-plastic behaviour for the adhesive. It w...
Improvement of the mechanical response of an electrical component
Antunes, F. J. V.; Costa, J. D. M.; Ferreira, J. A. M.The electrical component under analysis does not fulfil the mechanical performance required by the standard (a minimum force of 400 gf during the extraction of a 3.8 mm diameter pin after the introduction of a 5.1 mm pin). A numerical study using the finite element method was developed to understand the limited response of the component and to study the effect of changing material and geometry. Experimental tes...
Fatigue analysis of thin AlMgSi welded joints under constant and variable ampli...
Pinho-da-Cruz, J. A. M.; Ferreira, J. A. M.; Costa, J. D. M.; Borrego, L. F. P.This paper reports the fatigue behaviour of thin AlMgSi1 aluminium alloy weldments and the improvement in fatigue strength due to post-weld treatments. Several fatigue tests were performed using two distinct types of thin welded joints, T and single lap, manufactured using a 6xxx series aluminium alloy, and the efficiency of fatigue life improvement techniques, such as post-weld heat treatment and weld toe's bu...
Fatigue behaviour of composite adhesive lap joints
Ferreira, J. A. M.; Reis, P. N.; Costa, J. D. M.; Richardson, M. O. W.http://www.sciencedirect.com/science/article/B6TWT-45YG5WP-1/1/d57bc6251d123772bfdb57edd6cc3916
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