Screening significant properties of macro-fiber composite laminate substrate anisotropy with viscoelastic and thermal considerations at the quasi-static level

A macro-fiber composite (MFC) is a class of smart material actuator that employs piezoceramic fibers to extend or contract under an applied electric field. When embedded on a thin substrate, actuated MFCs induce surface pressure, resulting in out-of-plane motion. Design characteristics of the substrate, such as anisotropy, give rise to unique bend/twist behavior. Previous studies on MFC applications have focused on optimizing patch location in relation to the local design to achieve optimal bend/twist motion. However, the resolution to these approaches is restricted to the design space of the application, presenting an absence in piezoelectric laminate design intuition. This research aims to streamline the initial optimization process by analyzing the significant material properties associated with substrate design. To accomplish this, a viscoelastic piezoelectric plate theory model is developed to accurately capture the displacement behavior of the MFC laminate for any given substrate design. Experimental data is used to validate and refine the model, ensuring it closely represents real-world physics. A 2k fractional factorial design of experiments approach is used to identify significant substrate properties per MFC laminate configuration, assigning each material property a two-level coding system. Three configurations are observed, with each exhibiting distinct significant properties and effects compared to others. Furthermore, the study explores the impact of thermal factors on substrate behavior for these MFC laminates, highlighting how significant properties can be temperature dependent. The contributions to the kinematic response due to substrate property perturbation varies uniquely per material property and MFC laminate configuration. Statistical evidence supports the notion that the hysteretic behavior of a material is unaffected by thermal influences and is solely determined by the elastic constants of the substrate. The maximum remanent hysteretic response is shown to be proportional to the maximum actuation response at near room temperature.