Designing devices made from epoxy-based shape memory polymers is difficult because few material behavior parameters are available for these materials in the rubbery/shape changing region. This work examines the rubbery state, greater than 20° C above the glass transition temperature (Tg), as an elastomeric regime suited to characterization with simple tension and planar tension experiments. Differential scanning calorimetry (DSC) results show a 70° C Tg, which agrees with prior research. Simple tension experiments at 100° C exhibited nonlinear elastic behavior, and finite element analysis (FEA) agreed with the constitutive behavior exhibited in the experiments. Planar tension experiments exhibited novel results. The stress/strain response was sigmoidal with a significant plateau in stress followed by rising stress to failure. The typical 10:1 gage width/gage length ratio seemed to over constrain the material. The strain to failure is small, and suggests the material behavior is a hybrid of elastic and hyperelastic behavior.
- Aerospace Division
Toward Material Parameters for Modeling Devices Made From an Epoxy-Based Shape Memory Polymer
Erel, V, Berry, JL, Srinivasa, A, & Creasy, TS. "Toward Material Parameters for Modeling Devices Made From an Epoxy-Based Shape Memory Polymer." Proceedings of the ASME 2015 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. Volume 1: Development and Characterization of Multifunctional Materials; Mechanics and Behavior of Active Materials; Modeling, Simulation and Control of Adaptive Systems. Colorado Springs, Colorado, USA. September 21–23, 2015. V001T01A018. ASME. https://doi.org/10.1115/SMASIS2015-9043
Download citation file: