Damage Growth in Prestressed Plain Weave Fabrics

Abstract

A simplified micromechanics approach is used to develop a mathematical model to predict damage growth in prestressed plain weave fabrics near sites where yams are broken. Stress concentration in the yams neighboring yarn breaks is determined as a function of increasing loading. An evaluation of the load redistribution around the damage region includes a determination of the frictional slip of broken yams. Consid eration of equilibrium and deformation of constituent yams leads to linear differential equations for yarn displacements applicable to distinct regions where slipping does and does not occur. Slip frictional forces depend on yam normal contact forces at cross over points resulting from crimp interchange, Kawabata's model [12] is modified and used to motivate an analysis of frictional load transfer. The equations are nondimen sionalized, and dimensionless parameters involving both geometry and material prop erties are identified.