- Shape-memory polymer chemistry and design for active materials and morphing structures
- Covers shape memory in polymers, alloys and composites, including models and testing
- Essential equations for analysis of the structure, behavior and properties of SMPs
- Many graphs and figures in full color
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.
DEStech – :
In this book specialists at the forefront of shape memory polymers (SMPs) have been brought together to discuss the progress, current status and remaining challenges constricting SMPs’ successful application in an industry. It can be perceived that the book consists of five sections. The first section, ie Chapters 1 to 5, deals with the introduction to shape memory effect (SME) in SMPs realised by the glass transition and phase evolution and gradually proceeds to the narration of characterisation of shape memory response.
The second section, ie Chapters 6 to 8, covers the SMP modeling and simulation. Much effort has been given to review the constitutive models based on internal electronic structure changes and glass transition or viscoelasticity where 1D standard linear solid model is applied to capture the mechanism of SMEs in SMP. Another unique characteristic of SMP known as the multi-SME is captured by 1D multibranch model. The model description further extends to a review on finite deformation and thin-walled cylinder finite element simulations. Other modeling approach includes internal variable based phase transition models for thermally actuated SMPs. The internal variable approach illustrates the way to phenomenologically represent the molecular mechanism that is responsible for the SME.
The third section, ie Chapters 9 to 11, covers the shape recovery characteristic of SMP composites produced by a combination of shape memory alloy (SMA) wire and SMP matrix, SMA tube and SMP matrix, and two types of SMA tapes exhibiting SME and superelasticity that are sandwiched by the SMP tapes. The actuation capability of SMP composites is evaluated through the deployable hinge designed for the aerospace applications. In optimising the capability, the key factors included bending of curvature, design angle and shape of end fixture, layer thickness of the hinges, deployment stiffness and the manufacture technology. The heating method is also highlighted as a key factor to the deployment process of the hinge.
The fourth section, ie Chapters 12 to 13, investigates the incorporation of reinforcing fillers, with an aim to improve the mechanical properties and to diversify the applications of SMPs. Experimental investigations revealed that it would be possible to develop SMP resin and composite with a high Tg, good shape fixity and near complete recovery. Nanostructure tailoring of the SMP is presented at length – nanosized reinforcements considered are carbon nanotubes, carbon nanofiber, clay, polyhedral oligomeric silsesquioxane and hybrid filler. While carbon black-reinforced composites show limited shape recovery, carbon nanotube reinforced composites showed nearly full shape recovery. The SMP composites with graphene oxide (GO), with increasing percentage of GO showed improvements on toughness, tensile strength, elongation at break and scratch hardness. The fifth and final section, ie Chapters 14 to 18, effectively puts together the broad range of topics on SMPs and SMP composites used for the aerospace applications and the like. The topics extend from morphing aerostructures, unimorph composite actuators and thermal energy activated deployment of a packaged unmanned aerial vehicle to shape memory metal rubber morphing skins and printed active origami.
In summary, owing much to the broad coverage of the topics, the emphasis is clearly on the book’s subtitle: ‘Novel Synthesis, Modeling, Characterisation and Design’. Backed by the numerous examples with figures, tables and references, the book is an excellent resource for shape memory practitioners with applications in mind and recommended as an essential read for both novices and experienced engineers who are endeavoring to pin down the shape recovery characteristics of SMPs and SMP composites under various programmable and stimulus conditions.
—Dr Kiyohide Wada CEng, MIMechE, College of Engineering, Swansea University