Numerical and experimental study of the strength of fabric carbon-epoxy composite structures

The problem of adequate modeling of thin-walled laminate composite structures reinforced by woven fabrics is discussed in the paper. The conformity of numerical and experimental values of ultimate load is investigated. Standard-dimension strip-like specimens and lugs with quasi-isotropic layup of three standard sizes are used for the investigation. Static strength of the specimens has been tested. Finite-element models of the described structures are developed using the NASTRAN software. The accuracy of ultimate load prediction by several failure criteria (maximum stress, maximum strain, Tsai-Wu, Tsai-Hill, etc.) is analyzed. Recommendations for choosing failure criteria for laminate composite materials are given. The soundness of simplified modeling of contact interaction of the lug axis and hole surface by transferring the load from the hole surface to peripheral nodes using rod finite elements is discussed.