Stress concentrations in composites with interface sliding\ matrix sti}ness and uneven _ber spacing using shear lag theory

The stress concentrations near a single _ber break in a unidirectionally reinforced _ber composite are investigated using a shear lag theory within the framework of _nite elements[ A model for uniformly spaced\ well bonded _bers embedded in a matrix that cannot carry axial loads that was formulated previously is _rst introduced[ The solution of this problem involves Fourier transforms and requires only a two!dimensional numerical integration[ The work described in the current paper characterizes the stress concentrations around a single _ber break in the presence of _ber:matrix interface sliding\ axial matrix sti}ness and uneven _ber spacing[ Due to the introduction of these complicating factors\ the model no longer lends itself to the simple Fourier transformation solution method[ For the case of interface sliding a new method is developed to handle sliding in any shear lag system[ For the cases of axial matrix sti}ness and uneven _ber spacing a _nite element code speci_cally written for this problem is used to determine the _ber stresses[ The results are discussed in the context of global versus local load sharing\ and the e}ects on composite failure[ Þ 0888 Elsevier Science Ltd[ All rights reserved[