ADVANCES IN COMPOSITE MATERIALS - ECODESIGN AND ANALYSIS
Prediction of the longitudinal tensile strength
The temperature-related longitudinal tensile strength a//L of NASC can be calculated by Eq. (33).
°TL fd1 fi ffVf °J + fdVm cm
where fi = (1- Vt), °T is the mean stress in fibers when tensile failure occurs and it can be obtained from the micromechanical model of NASC, °/ is the mean stress in the matrix
when tensile failure occurs and °/ = E/A, and fd is the weakening coefficient of rubber induced by fibers.
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When the aspect ratio X is smaller than the critical value 1^, the debonding between fibers and the matrix will occur. However, when X>Xc, the fiber breaks. Therefore, the temperature-related longitudinal tensile strength can be calculated according to Eq. (34).
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where AaJ is the stress in fibers induced by temperature change and Att is the shear stress
