Analysis of stresses in aluminum particles embedded inside unidirectional and woven graphite/polyimide composites subjected to large bending loads

The effect of large bending loads on strains and stresses inside aluminum particles embedded in unidirectional and woven eight harness satin (8HS) graphite/PMR-15 composites has been examined. The stresses and strains in the particles were determined by performing X-ray diffraction (XRD) measurements. It has been shown in this work that when the composites are subjected to large four-point bending loads, above certain critical loads, the normal stresses and strains in the particles no longer respond to an increase in the bending moments. The stabilization of the normal X-ray stresses and strains under large bending conditions was attributed to the onset of plastic deformation of the particles. It has also been shown in this study that the aluminum particles do not noticeably affect the mechanical behavior of the composites under four-point bending conditions.