Nonlinear tensile and shear behavior of macro fiber composite actuators

The Macro Fiber Composite (MFC) actuator, developed at the NASA Langley Research Center, offers much higher flexibility and induced strain levels (similar to2000 muepsilon, peak-to-peak) than its monolithic piezoceramic predecessors. The focus of this work is twofold; to measure the four independent linear elastic engineering constants of the orthotropic MFC actuator under short-circuit electrical boundary conditions using standard tensile testing procedures, and to use these experimental results to characterize the nonlinear tensile and shear stress-strain behavior and Poisson effects using various plastic deformation models. The results can then be readily incorporated into the piezoelectric constitutive equation and ultimately into structural actuation models that accurately consider nonlinear mechanical behavior.