A Model To Study Slit Damaged Braided Fabric Structures
Free (open access)
J. N. Rossettos & T. A. Godfrey
A micromechanical model has been developed that will allow the study of a slit-damaged braided fabric air-beam structure. As such, the relevant system of non-dimensional ordinary differential equations is derived and solutions are given for the stress concentration near the broken yarns. This knowledge will contribute to the prediction of damage growth and the ability to compare different fabric materials for their damage tolerance. A simplification of the analysis has been shown to be possible when a parameter, e , the ratio of yarn tensions due to inflation to the yarn stiffness is small, approaching zero. In such a case, the equations for the braided fabric can be reduced to those of the plain weave fabric, so that the stress concentrations are the same as those for woven fabrics. As it turns out, an important result of the present analysis is that the stress concentration factor is, in fact, independent of the parameter, e , and the helix angle of the braided fabrics. This means that much of what has been learned in the study of damage in woven fabrics can be used for braided fabrics. Keywords: braided fabrics, stress concentration, damage growth, air-beam structures. 1 Introduction In addition to woven fabric air-beams currently in development and production for large shelters and space structures, a braided fabric air-beam technology has emerged. Much work has already been done in studying damage growth in woven fabrics [1-4], where the yarns of the weave are oriented normal to one
braided fabrics, stress concentration, damage growth, air-beam structures.