Thermo-oxidation behaviour of composite materials at high temperatures: A review of research activities carried out within the COMEDI program

The present paper presents a review of the main activities carried out within the context of the COMEDI research program, a joint collaboration involving three research teams focusing on the thermo-oxidation behaviour of composite materials at high temperatures. The scientific aim of the COMEDI research program was to better identify the link between the physical mechanisms involved in thermo-oxidation phenomena: oxygen reaction-diffusion, chemical shrinkage strain/stress, degradation at different scales and to provide tools for predicting the thermo-oxidation behaviour of composite materials under thermo-oxidative environments including damage onset. This aim was accomplished by investigating experimentally the thermo-oxidation behaviour of pure resin samples - both industrial and "model" materials - and by interpreting the results by a coupled reaction-diffusion-mechanics multiphysics model. A dedicated numerical model tool has been developed and implemented into the ABAQUS® finite element commercial software. This tool was employed to simulate the thermo-oxidative behaviour of a fibre-matrix microscopic representative composite cell. Finally, the model predictions for the composite have been validated by comparing the experimental and the simulated local matrix shrinkage displacements and the mass loss of composite specimens

"Maximum curvatures of 0/90 plates under thermal stress : modelling and experimental validation."

International audienc

Experimental study to assess the effect of carbon nanotube addition on the through-thickness electrical conductivity of CFRP laminates for aircraft applications

International audienceThe present paper tests experimentally the through-thickness electrical conductivity of carbon fiber-reinforced polymer (CFRP) composites laminates for aircraft applications. Two types of samples were prepared: Type A samples with carbon nanotubes (CNTs) and Type B samples without CNTs. During the electrical experiments, electrical currents of several mA were injected through the specimens. Electrical resistance was monitored simultaneously in order to deduce the changes in the through-the-thickness electrical conductivity caused by the addition of CNTs. Improvement of electrical conduction by two orders of magnitude was achieved through the addition of 1 wt% carbon nanotubes as compared to classic CFRP without CNTs. For moisture saturated samples, the influence of moisture absorption on such measures was found to be negligible. (C) 2015 Elsevier Ltd. All rights reserved

Habilidades Sociais em Alcoolistas: Um Estudo Comparativo

The present study aimed to compare the repertoire of social skills of alcoholics and non-alcoholics in order to verify if a minor repertoire of social skills constitute a feature of this population. Interviews were carried out with 123 alcoholics and 114 users of health service patients with low or no consumption of alcohol. It were used a socio-demographic questionnaire, the Mini International Neuropsychiatric Interview and the Social Skill Inventory. The data were analyzed quantitatively and the results indicated a significant difference in repertoire of social skills, specifically with respect to the factor of self-control of aggressiveness, on which was demonstrated the worst performance. The results suggest that the evaluation of this feature should be considered in the treatment of alcoholism and associated with a therapeutic plan.O presente estudo objetivou comparar o repertório de habilidades sociais (HS) de dependentes e não dependentes de álcool a fim de verificar se um menor repertório de HS constitui uma característica dessa população. Foram entrevistados 123 alcoolistas e 114 usuários de serviços de saúde com baixo ou nenhum consumo de álcool, utilizando questionário sociodemográfico, Mini International Neuropsychiatric Interview e o Inventário de Habilidades Sociais. Os dados foram analisados quantitativamente e indicaram uma diferença significativa no repertório de HS, especificamente no fator de autocontrole da agressividade, indicando um pior desempenho dessa habilidade em alcoolistas. Os resultados sugerem que a avaliação dessa característica deva ser considerada no tratamento do alcoolismo e associada ao plano terapêutico