Photoelastic analysis of interlaminar matrix stresses in fibrous composite models

Scattered-light methods are presented for analysis of interlaminar matrix stresses between the fiber layers of composite models. These include data-smoothing techniques and a least-squares solution to utilize the excess information available. Applications are given to determine all stress components in the matrix of a two-layer model and to determine the interlaminar shear stress in the matrix of a four-layer model. The results indicate that matrix stress magnitudes are a function of proximity to the fibers and that they are significantly higher than composite stresses obtained using mathematical models. Paper was presented at 1975 SESA Spring Meeting held in Chicago, IL on May 11–16.