Structural integrity of composite laminates with interlaced actuators

Abstract

A three-dimensional finite-element model is developed to analyze the interlaminar stress state surrounding an interlaced, active actuator embedded within a unidirectional composite laminate. Interlacing increases the strength of composite structures with embedded actuators by redistributing the load around the inclusion and softening the material discontinuity between the actuator and the composite structure. The analysis shows that interlacing results in as much as a 42% reduction in the magnitude of the maximum interlaminar tensile normal stress and a 22% reduction in the magnitude of the maximum interlaminar shear stress in the laminate. Moreover, the critical location of delamination initiation can be relocated from the interface between the actuator and the host material to a location away from the embedded actuator, thus maintaining the authority of the actuator even after the onset of delamination.