Issue 50

M.A. Khiat et alii, Frattura ed Integrità Strutturale, 50 (2019) 595-601; DOI: 10.3221/IGF-ESIS.50.50 600 Figure 4 : Evolution of the stress concentrations according to the number of broken fibers with progressive variation of moisture concentration for T=20° and  = 0.5  0 . Figure 5 : Evolution of the stress concentrations according to the number of broken fibers with progressive variation of moisture concentration for T=120° and  = 0.5  0 . C ONCLUSIONS he aim of this work is to develop a better understanding of how temperature and moisture may affect the stress concentration of unidirectional composite materials, in terms of the number of broken fibers. By introducing the micromechanical characterization with changes in temperature and moisture concentration, the proposed model enables the prediction of changes in stress concentrations in the neighboring fibers. Consequently, the interface fiber/matrix is concerned by changes in the matrix properties because the stress is transferred to the neighboring fibers. If the surrounding matrix becomes less stiff, the ineffective length becomes larger and the fiber fractures regions will interact more easily and may connect together to cause complete failure. T