Cette thèse consiste en une étude comparative des propriétés thermomécaniques de composites tissés à matrice thermoplastique (PEEK ou PPS) et thermodurcissable (époxy). Une analyse bibliographique a permis la comparaison les comportements des ces stratifies en fonction de la nature de la matrice, de la sollicitation et des conditions environnementales. Une étude expérimentale a conduit à une base de données des trois matériaux sous diverses sollicitations mécaniques (essais monotones élémentaires et structures) et différentes conditions environnementales (température et V.H.). Des essais sur assemblages boulonnes (simple et double recouvrement) ont également été réalisés. Une technique de mesure de champ par corrélation d’images numériques a permis d'étudier le comportement de stratifies troues. Enfin, un modèle de comportement élastoplastique orthotrope de stratifies tisses a matrice thermoplastique a été implémenté dans le code E.F. cast3m et valide pour différentes températures. / This PhD thesis consists in a comparative study of the thermomechanical properties of woven plies composites with a thermoplastic (PEEK or PPS) or a thermosetting (epoxy) matrix. A literature review allowed the comparison between the behaviors of these laminates depending on the matrix nature, the stress state and the environmental conditions. An experimental study led to a database of the three materials for different mechanical loads (monotonic and structural tests) under specific environmental conditions (temperature and wet ageing). Bolted joints tests (single bolt single lap and double lap) have also been performed. A digital pictures correlation technique permitted to study the behavior of circular notched laminates. At last, a model of orthotropic elastoplastic behavior for woven plies laminates with a thermoplastic matrix has been implemented in the F.E. code cast3m and has been validated for different temperatures.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-07-19T18:00:38Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ronan_peixoto_gontijo.pdf: 1104745 bytes, checksum: 61495fad179d3458b9a10be7203acb6e (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-08-22T12:55:16Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ronan_peixoto_gontijo.pdf: 1104745 bytes, checksum: 61495fad179d3458b9a10be7203acb6e (MD5) / Made available in DSpace on 2018-08-22T12:55:16Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ronan_peixoto_gontijo.pdf: 1104745 bytes, checksum: 61495fad179d3458b9a10be7203acb6e (MD5) Previous issue date: 2017 / Objetivou-se avaliar os efeitos das t?cnicas de matura??o a v?cuo (wet ageing) e a seco (dry-ageing) nas caracter?sticas de qualidade da carne bovina proveniente do m?sculo dianteiro semispinales thoracis de animais Nelore. Foram processados 40 cortes, com peso ap?s toalete de aproximadente 2000g. Estes cortes foram maturados pelas duas t?cnicas de matura??o (embalados em polietileno para t?cnica a v?cuo e sem embalagem para t?cnica a seco) em c?mara fria padr?o comercial, com temperatura m?dia de 3?C e umidade relativa do ar m?dia de 69% durante 5 tempos, a saber: 0, 7, 14, 21 e 28 dias. Os cortes maturados pela t?cnica a seco foram diariamente virados e aspergidos com solu??o de 2% (v/v) de ?cido ac?tico. Os cortes da t?cnica a v?cuo foram aspergidos com a mesma solu??o e imediatamente embalados a v?cuo. Em cada tempo de matura??o foram avaliados rendimentos, for?a de cisalhamento, cor (L a* b* C and H ?), capacidade de reten??o de ?gua, perda de peso por coc??o, pH, quantifica??o superificial de coliformes totais e termotolerantes, assim como os teores de prote?na, gordura, massa seca e res?duo mineral fixo. N?o foram verificadas diferen?as (P>0,05) para a for?a de cisalhamento, perda de peso por coc??o, pH, par?metros microbiol?gicos e bromatol?gicos, com o decorrer dos 28 dias de matura??o, para ambas as t?cnicas. Na carne maturada ? v?cuo foram observados (P<0,05) aumento no croma e diminui??o na capacidade de reten??o de ?gua. A carne maturada a v?cuo apresentou os maiores rendimentos totais (P<0,05) comparada com a carne maturada a seco. A carne maturada ? seco apresentou maior capacidade de reten??o de ?gua e menor perda de peso por coc??o, em compara??o a carne maturada a v?cuo. A matura??o a seco por 21 dias proporcinou estabilidade da cor sem altera??es nos par?metros f?sico-qu?micos e redu??o na for?a de cisalhamento da carne proveniente do m?sculo semispinalis thoracis. A matura??o a v?cuo por 28 dias proporcionou redu??o da for?a de cisalhamento da carne proveniente do m?sculo semispinalis thoracis. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The objective of this study was to evaluate the effects of vacuum (wet-ageing) and dry-ageing techniques on the quality characteristics of bovine meat from the semispinales thoracis muscle of Nellore animals. 40 cuts were processed, with weight after trim of approximately 2000g. These cuts were matured by the two maturation techniques (packed in polyethylene for vacuum technique and without packaging for dry technique) in a commercial standard cold chamber, with a mean temperature of 3?C and a relative humidity of 69% for 5 times , namely: 0, 7, 14, 21 and 28 days. The sections matured by the dry-ageing technique were tacked daily and sprayed with a 2% (v / v) solution of acetic acid. The vacuum technique cuts were sprayed with the same solution and immediately vacuum packed. At each maturation time, yields, shear force, color (L a* b* C and H ?), water retention capacity, weight loss by cooking, pH, superificial quantification of total and thermotolerant coliforms, the levels of protein, fat, dry matter and fixed mineral residue were evaluated. No differences (P> 0.05) were observed for the shear force, weight loss per cooking, pH, microbiological and bromatological parameters, during the 28 days of maturation, for both techniques. In the vacuum packed meat (P <0.05), chroma increase and decrease in water retention capacity were observed. The vacuum packed meat had the highest total yields (P <0.05) compared to dry-aged meat. Dry-aged meat had a higher water retention capacity and less weight loss per cooking compared to vacuum packed meat. Dry maturation for 21 days provided color stability without changes in the physical-chemical parameters and reduction in the shear force of the meat from the semispinalis thoracis muscle. The 28-day vacuum maturation provided a reduction in the shear force of meat from the semispinalis thoracis muscle.