Zhao Wang¹, Jun Liu¹, Xiaoying Qi², Chadur Venkatesan², Sharon Nai², David W. Rosen^1,2,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.31, No.4, pp. 1-2, 2024, DOI:10.32604/icces.2024.011890

Abstract Shape memory polymers (SMP) have many applications as actuators in soft robotics. However, predicting their shape change behavior is challenging, which makes designing suitable actuators difficult. For thermally stimulated shape memory polymers, constitutive models of shape change behavior show promise in enabling predictable shape changes, which is necessary for actuator design. These models are usually classified as either rheological or phase transition, with the former being more general, although non-physical in nature, and the latter being more physically significant [1]. Of interest in this work is 2-state shape change transitions for single-material actuators; that is,… More >

MANIKANDAN.N^1,*, RAJESH.P.K¹

Journal of Polymer Materials, Vol.38, No.3-4, pp. 327-336, 2021, DOI:10.32381/JPM.2021.38.3-4.12

Abstract In this research, a new method to fabricate multi-material, multi-shape changing polymer composites is proposed. The method aims to reduce the number of thermomechanical programming steps involved in achieving shape change in a shape memory polymer (SMP) composite structure by including the programming steps directly into the printing process. After a single step of mechanical deformation and thermal loading, the SMP fibers can be activated sequentially to control the shape change. Composite strip samples were fabricated using a Stratasys Objet 260 multimaterial printer. Two polymer inks VeroPureWhite and Agilus30 were used as primary materials. The… More >

KRISHAN KUMAR PATEL, RAJESH PUROHIT

Journal of Polymer Materials, Vol.36, No.1, pp. 23-37, 2019, DOI:10.32381/JPM.2019.36.01.3

Abstract Microwave (MV)-induced thermo-responsive shape memory thermoplastic polyurethane (SMTPU)/ MWCNT composites were prepared in micro-compounder. Composites containing different amount of multiwall Carbon nanotube (MWCNT) varying from 0 to 1.5 phr in SMTPU matrix were prepared. Maximum stretching strength, recovery force and tensile strength for 1.5 CNTPU (1.5 phr MWCNT in SMTPU matrix) was increased by 120%, 100% and 24% respectively as compared to SMTPU. MV-induced shape memory is a novel approach for fast, clean and remote heating during operation. MWCNT is strong absorber of microwave irradiation so that SMTPU/ MWCNTs nanocomposites successfully triggered by microwave. More >

Guanghui Shi¹, Qingsheng Yang^1,2, Xiaoqiao He^3,4, Kim Meow Liew³

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.5, pp. 339-358, 2013, DOI:10.3970/cmes.2013.090.339

Abstract In order to describe the thermomechanical deformation and shape memory effect of shape memory polymers (SMPs), a three-dimensional thermomechanical constitutive model that considers elastic, viscoelastic strain and thermal expansion is proposed for isotropic SMPs. A three-dimensional finite element procedure is developed by implementing the proposed constitutive model into the user material subroutine (UMAT) in ABAQUS program. Numerical examples are used to compare it with existing experimental data in a one dimensional case and to demonstrate the thermomechanical behavior of SMPs with 3D deformation. It is shown that the present constitutive theory and the finite element More >

Z.D. Wang¹, D.F Li¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.4, pp. 245-254, 2008, DOI:10.3970/icces.2008.005.245

Abstract The thermo-mechanical constitution of shape memory polymers (SMPs) is critical for predicting their deformation and recovery characteristics under different constraints. In this study, a new, physical-based, temperature and time-dependent constitutive model is proposed for simulating the thermomechanical response of SMPs. The deformation mechanisms of shape fix and shape recovery are analyzed. Different models are compared to compare strain and stress recovery responses with the experimental results. More >