DAMAGE GROWTH IN PRESTRESSED PLAIN WEAVE FABRICS

A simplified micromechanics approach is used to develop a mathematical model to predict damage growth in prestressed plain weave fabrics nea r sites where yarns are broken. Stress concentration in the yarns neig hboring yarn breaks is determined as a function of increasing loading. An evaluation of the load redistribution around the damage region inc ludes a determination of the frictional slip of broken yarns. Consider ation of equilibrium and deformation of constituent yarns leads to lin ear differential equations for yarn displacements applicable to distin ct regions where slipping does and does not occur. Slip frictional for ces depend on yarn normal contact forces at crossover points resulting from crimp interchange; Kawabata's model [12] is modified and used to motivate an analysis of frictional load transfer. The equations are n ondimensionalized, and dimensionless parameters involving both geometr y and material properties an identified.