Multiphysics thermo-mechanical constitutive modeling of elastomeric polymers: Toward the 4D printing of shape memory metastructures

초록

Shape memory polymers (SMPs) are smart materials capable of undergoing programmed shape transformations in response to external stimuli, making them highly attractive for next-generation engineering applications spanning biomedical, aerospace, and soft robotics. This research develops a Multiphysics thermo-mechanical constitutive model for elastomeric-based SMPs, which are promising candidates for additive manufacturing techniques, particularly 4D printing. This study introduces a shape memory performance index to quantify their thermo-mechanical adaptability. A time-discrete finite element analysis (FEA) was performed to simulate the stress-strain response of a cantilever beam geometry for two material blends of SMPs, PP-POE (polyolefin-elastomers) and PLA-POE (polyester-elastomers), with transition temperatures in the 30-65 °C range. The multiphysics simulation integrated viscoelastic behavior and phase transition mechanisms using ANSYS Workbench and MATLAB. The FEA results were validated against experimental data to verify the accuracy of the constitutive formulation. The performance of the two SMPs was investigated under a time-And temperature-dependent transient conditions to capture the programming (permanent deformation), fixation (temporary shape retention), and recovery phases. The results indicate a direct correlation between material stiffness and induced peak stresses during programming. Under identical displacement-Temperature loading conditions, the PP-POE blend exhibited approximately three times lower peak stress compared to PLA-POE, while achieving higher shape recovery (85.2% versus 77.1%). This work establishes a computational foundation for the design and optimization of shape memory polymers and provides insight into material selection strategies for additive manufacturing applications, particularly in the emerging 4D printing meta-structures. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

키워드