The inelastic deformation behavior of PMR-15 neat resin, a high-temperature thermoset polymer, was investigated at 288 degrees C. The experimental program was designed to explore the influence of strain rate on tensile loading, unloading, and strain recovery behaviors. In addition, the effect of the prior strain rate on the relaxation response of the material, as well as on the creep behavior following strain controlled loading were examined. The experimental data were modeled with the Viscoplasticity Based on Overstress (VBO) theory. A systematic procedure for determining model parameters was developed and the model was employed to predict the response of the material under various test histories. Additionally the effects of prior aging at 288 degrees C in argon on the time (rate)-dependent behavior of the PMR-15 polymer were evaluated in a series of strain and load controlled experiments. Based on experimental results, the VBO theory was extended to capture the environmentally induced changes in the material response. Several of the VBO material parameters were expanded as functions of prior aging time. The resulting model was used to predict the high-temperature behavior of the PMR-15 polymer subjected to prior aging of various durations.

A technical analysis of shape-memory polymers (SMPs) and their composites, particularly in adaptive materials, this volume introduces designs linking SMPs to metals, elastomers, foams, nanoparticles and other materials, as well as the engineering of SMPs directly into parts and active (morphing) components. Attention is given to controlled structures activated by light, heat, electricity and other energy sources, as well as the connection of SMPs with actuators. Part one discusses the activation and analysis of the shape memory response, including shape recovery. Subsequent chapters offer modeling and other tools for investigating the SMP response, including shape recovery. Part three combines the response with micro- and macro-scale reinforcing phases for producing SMP composites, and the following section discusses synthetic and nanostructured customization of the shape memory polymer response. The final section focuses on specific SMP concepts in aircraft, including morphing skins, wings, unimorph composite actuators for deployment, and variable stiffness elements.Some of the highlights of the book include: Shape-memory polymer chemistry and design for active materials and morphing structures. Essential equations for analysis of the structure, behavior and properties of SMPs. Many graphs and figures in full color .