Design and analysis of smart diaphragm based on shape memory polymer

Abstract

Currently, tank diaphragms are mostly applied in the field of aerospace but one of their limitations have to do with their inability to recycle. In the article, we discussed the modeling of a new kind of reversible diaphragm, so‐called shape memory polymer (SMP) diaphragm. A thermo‐mechanical modeling of SMP is implemented by the finite element method using a constitutive model. A single variable in this model is defined and used to simplify the model compared to other existing models. Evolution of the analysis is conducted by making use of the intermediate difference forms and Jacobian matrix, which is applied to all quantities within the model. The overturning and recovery behaviors of the SMP diaphragm are examined. And, the effect of several parameters, including thickness, height and radius of the diaphragm, as well as temperature on the overturning performance are investigated. This study led to the establishment of an optimized model with the objective function requiring minimum overturning pressure for completing deformation and design variables associated with thickness, height, radius, and temperature. An optimized SMP diaphragm is obtained under the critical pressure constraints. The results contribute to the design and application of novel SMP diaphragms. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46557.

Four-dimensional printed self-deploying circular structures with large folding ratio inspired by origami

“…In the process of temperature change, SMPs will undergo a transition between the glass state and the rubber state, and therefore, their material properties will also change significantly. In order to describe the thermo-mechanical behavior of SMPs, Tao et al (2018) established a relationship between material parameters and temperature. The function of the reversible strain in terms of the material parameters is where m h and m l represent the viscosity coefficient at high temperature and low temperature, respectively, and T hl is the temperature difference between low and high temperature at the glass transition temperature range.…”

“…In the process of temperature change, SMPs will undergo a transition between the glass state and the rubber state, and therefore, their material properties will also change significantly. In order to describe the thermo-mechanical behavior of SMPs, Tao et al (2018) established a relationship between material parameters and temperature. The function of the reversible strain in terms of the material parameters is…”

A highly-compressible, torsion-contraction coupling and self-transforming cylindrical bi-material metastructure

“…During the glass transition, the mechanical properties of SMPs change greatly. In order to describe the thermomechanical behavior of SMPs, Tao et al [39] established a relationship between material parameters and temperature. Firstly, a function that describes the reversible strain and the material parameters was constructed, specifically described as:…”

Finite element analysis of shape-memory polymer mast

“…According to the previous research [46], a function describing temperature and material parameters is introduced into the constitutive model to explain the changes of polymer material parameters and strain during the process of shape memory [31], which is expressed as:…”

“…They are capable of changing its size and shape when activated through a suitable stimuli like heat [22][23], light [24][25], electricity [26][27], solution [28], and so on [29][30][31]. SMPs are particularly promising in aerospace [20][21][22][23][24][25][26][27][28][29][30][31][32], biomedical [33][34], additive manufacturing [35][36], and other engineering fields [37][38][39] owing to their characteristic of high deformability, high shape recoverability and easy processing [40][41]. Thermal-responsive SMPs are the most prospective SMPs because of their simple stimulus form and fast response [42]; thus, they are investigated in the present work.…”