Elastic Region Research Articles

Strain-dependent elastography of cancer cells reveals heterogeneity and stiffening due to attachment

Because cells vary in thickness and in biomechanical properties, the use of a constant force trigger during atomic force microscopy (AFM) stiffness mapping produces a varied nominal strain that can obfuscate the comparison of local material properties. In this study, we measured the biomechanical spatial heterogeneity of ovarian and breast cancer cells by using an indentation-dependent pointwise Hertzian method. Force curves and surface topography were used together to determine cell stiffness as a function of nominal strain. By recording stiffness at a particular strain, it may be possible to improve comparison of the material properties of cells and produce higher contrast representations of cell mechanical properties. Defining a linear region of elasticity that corresponds to a modest nominal strain, we were able to clearly distinguish the mechanics of the perinuclear region of cells. We observed that, relative to the lamelopodial stiffness, the perinuclear region was softer for metastatic cancer cells than their nonmetastatic counterparts. Moreover, contrast in the strain-dependent elastography in comparison to conventional force mapping with Hertzian model analysis revealed a significant stiffening phenomenon in the thin lamellipodial region in which the modulus scales inversely and exponentially with cell thickness. The observed exponential stiffening is not affected by relaxation of cytoskeletal tension, but finite element modeling indicates it is affected by substrate adhesion. The novel cell mapping technique explores cancer cell mechanical nonlinearity that results from regional heterogeneity, which could help explain how metastatic cancer cells can show soft phenotypes while simultaneously increasing force generation and invasiveness.

The substantiation of the composition of a soft medicine for the therapy of inflammatory diseases of the musculoskeletal system

Aim. To substantiate the optimal composition of the base of the semisolid dosage form with the thick extract of feverfew (Tanacetum parthebased on structural-mechanical, textural, adhesive and microscopic studies. Materials and methods. The study objects were samples of a semisolid dosage form with the thick extract of feverfew with various gelling agents and the reference drug “Irikar”. In the course of the research, a complex of structural-mechanical methods and the microscopic analysis of the samples were used. Results and discussion. The studies of structural-mechanical properties have determined the regularities in the rheological characteristics of the experimental samples made using different gelling agents. It has been found that the rheogram of the emulgel sample has a smooth transition from the elastic deformation region to the elastic-plastic one, which may indicate a more homogeneous distribution of the sample components. It has been also determined that the sample corresponds in the textural properties to the refenium) rence drug – “Irikar” cream. The structural-mechanical studies have substantiated the rational content of the gelling agent in the emulgel composition – 3 %. The results of rheological studies have been confirmed by the data of the microscopic studies. Conclusions. The data obtained are the basis for further pharmaceutical development of a drug with the thick extract of Tanacetum parthenium for the treatment of diseases of the musculoskeletal system.

Effect of high-pressure hydrogen environment in elastic and plastic deformation regions on slow strain rate tensile tests for iron-based superalloy A286

To investigate the effects of a high-pressure hydrogen environment in the elastic and plastic deformation regions, we performed slow strain-rate tensile tests of iron-based superalloy A286 at 150 °C by switching the atmosphere from 70 MPa hydrogen to air during the tests. The relationship between the nominal strain exposed to a hydrogen environment and the relative reduction in area (RRA) revealed that in the plastic deformation region, the RRA value decreased gradually depending on the nominal strain exposed to hydrogen, but in the elastic deformation region, the RRA value decreased rapidly. The RRA value further decreased when the stress cycle was applid in the elastic region. The fracture surface exhibited an intragranular slip plane fracture similar to that of the hydrogen-charged specimen. These phenomena suggest that the lattice decohesion theory is dominant in the elastic region, where hydrogen embrittlement occurs owing to an increase in the content of dissolved hydrogen.

The Role of Coupling Agents in the Mechanical and Thermal Properties of Polypropylene/Wood Flour Composites

This work is a collaborative effort between academia and industry to promote the development of new sustainable and profitable materials for manufacturing products. Incorporating wood flour particles (WF) in polypropylene (PP) grants environmental advantages in developing products that use renewable resources to manufacture PP/WF composites using the melt intercalation process. However, the interaction between a hydrophilic strengthening phase (wood flour) with a nonpolar polymer matrix (PP) is poor, resulting in deficient mechanical performance. This investigation details the use of graft and masterbatch coupling agents to evaluate their effects on mechanical parameters. The low compatibility between the constituents favors increasing the composites’ thermal properties because the reinforcing phase acts as a nucleating agent. PP showed typical mechanical behavior, with a marked necking and a wide deformation capacity of approximately 180%. The mechanical behavior of the PP/WF composites revealed an elastic region followed by a termination after their yield point, shortening the stress–strain curves and reducing their ductility at strain values of approximately 2–4%. Graft coupling agents have better intermolecular performance with PP than masterbatch coupling agents. The modulus of elasticity of the composites increased to around 82% relative to PP. Processing methods influenced the thermal properties of the composites. The melt-blending process promoted molecular orientation, while injection molding erased the thermomechanical history of the extruded pellets. The melting temperature was similar in the composites, so there was no evidence of thermal degradation. The results showed that the coupling agents favor the crystallinity of the PP over tensile strength. SEM observations showed insufficient adhesion between the WF and PP, which promotes a reduction in stress transfer during tensile testing. The WF particles act as fillers that increase the stiffness and reduce the ductility of composites.

Effect of Shear Strain on the Supercooled Itraconazole

This article investigated the effect of shear strain on the nematic itraconazole (ITR) from both elastic and plastic deformation regions. The rheo-dielectric technique was used for this purpose. It has been demonstrated that shear strain can change the sample color, liquid crystal alignment as well as its dielectric and thermal properties. The observed modifications depend on the shear strain value. One can distinguish four regions regarding the slope of ITR stress–strain dependence and caused changes. Proper alignment changes (obtained after the shearing procedure) can additionally affect the further recrystallization of ITR to other than the initial, i.e., second polymorphic form.

Finite element analysis on yield surface evolution of cellular materials

The yield surface is the boundary of elastic region in the theory of plasticity, therefore the area and the shape of the yield surface can represent the capability of cellular materials in the stress space. The yield point and the yield surface of one kind of 2D cellular materials, hexagonal honeycombs, is investigated in this study via the finite element analysis with a representative block approach. All components of requisites to computationally investigate yield surface evolution of 2D cellular materials are prepared. A proper determination of yield point for the honeycombs is proposed for the detection of initial and subsequent yield surfaces in the axial-shear stress space and the yield point determination is validated by the comparison between experimental result and finite element analysis. Taking into account a wide range of relative density for honeycombs, the mesh size as well as the pattern and the size of the representative block in finite element is investigated and selected based on the analysis of the mesh convergence analysis, the boundary effect, and the size effect. After probing paths and preloading paths are designed, the initial and subsequent yield surfaces of the honeycombs with different relative density are detected and the influence of relative density on the yield surface evolution is investigated. The investigation shows a shear preloading path followed by an axial preloading path strengthens the capability of honeycombs and the honeycomb with lower relative density may exhibit different behavior of yield surface evolution than those with higher relative density. Further, phenomena of cellular materials including the Bauschinger effect and the hardening behavior (isotropic, kinematic, rotation, distortional) are observed from the yield surface evolution of honeycombs.

Short-term vancomycin and buffer soaking does not change rabbit achilles tendon tensile material properties

BackgroundAllograft tendons are commonly used during orthopedic surgery to reconstruct tissue that is severely damaged. Soaking the tendon in an antibiotic solution, specifically vancomycin, has been shown to lower the risk of post-operative infections. While some material properties of tendon and ligament after antibiotic soaking have previously been characterized, extensive sub-failure allograft tendon material properties after soaking in antibiotic solutions have not. MethodsForty tendons were dissected from rabbits and soaked in either a phosphate buffered saline (PBS) only solution or vancomycin and PBS solution for five or 30 min. Immediately after soaking, quasi-static tensile experiments were performed in a materials testing system. FindingsTissue nominal stress, Lagrange strain, toe-region properties and elastic modulus were characterized. For all forty tendons, the average elastic modulus was found to be 455 ± 37 MPa, the average transition strain (from toe-region to linear elastic region) was 0.0487 ± 0.0035, and the average transition stress was 9.71 ± 0.79 MPa. No statistically significant differences in any of these material properties were found across soaking medium or soaking time. InterpretationFrom these results, we conclude that soaking an allograft tendon in antibiotic solution for up to 30 min prior to implantation does not change the tensile material properties of tendons, supporting current clinical practice.

Evolution of degradation mechanism and fixation strength of biodegradable Zn–Cu wire as sternum closure suture: An in vitro study

This work reports the first in vitro study on the in-situ biodegradation behaviour and the evolution of fixation strength of Zn–Cu alloy wires in a simulated sternum closure environment. Zn–Cu wires were used to reapproximate the partial bisected sternum models, and their fixation effect was compared with traditional surgical grade 316 L stainless steel (SS) wires in terms of fixation rigidity, critical load, first/ultimate failure characteristics. The metal sutures were then immersed in Hank's balanced salt solution for 12 weeks immersion period, and their corrosion behaviours assessed.Zn–Cu wires showed similar fixation rigidity at 70.89 ± 6.97 N/mm as SS, but the critical load, first failure and ultimate failure characteristics were inferior to SS. The key challenges that limited the fixation effect of the Zn–Cu wires were poor mechanical strength, short elastic region, and strain softening behaviours, which resulted in poor load-bearing capabilities and reduced the knot security of the sutures. The in-situ biodegradation of the Zn–Cu suture was accompanied by the early onset of localised corrosion within the twisted knot and the section located next to the incision line. Crevice corrosion and strain-induced corrosion were the dominant mechanisms in the observed localised corrosion. The localised corrosion on the Zn–Cu sutures did not lead to a significant shift in fixation rigidity, critical load and the first failure characteristics. The findings suggest that the Zn-based biodegradable metallic wires could be a promising sternum closure suture material once the limitations in mechanical characteristics are addressed.

Effect of Overburden Depth and Stress Anisotropy on a Ground Reaction Caused by Advancing Excavation of a Circular Tunnel

The assumption of the Convergence–Confinement Method (CCM) is the analysis of the interaction behavior of the support and ground of a deep circular tunnel under an isotropic stress field. Aiming to improve this method, this paper proposes a discussion on the influence of the overburden depth and stress anisotropy. To consider the influence of the overburden effect, the ground reaction in different depths due to tunnel advancing excavation is investigated. Under anisotropic stress conditions, the analytical solutions of the stress/displacement in the plastic and elastic regions of this ground reaction can also be suitable for theoretical analysis in a consistent manner. The key factor in this study is the use of confinement loss, which can not only describe the simulation of tunnel advancing effects but also become a superimposed value of the incremental procedure. In addition, the calculation spreadsheets can be used to estimate and implement the theoretical analytical solutions into executable computational solutions. To check the validity of the analytical solution, finite element analysis is used to examine the distribution of stress/displacement around the tunnel, especially the distribution along the overburden pressure line in the circular tunnel cross-section. Comparing the analytical solution calculated by the incremental procedure with the result of the numerical analysis shows a consistent trend.

The application of standard nonlinear solid material models in modelling the tensile behaviour of the supraspinatus tendon

Tendons transmit forces from muscles to bones through joints. Typically, tendons and muscles work together to innovate a motion. In addition, tendons are often subjected to much higher stresses than the muscles that they serve in any given action. As a result, tendons are susceptible to injuries that may lead to a permanent dysfunction in joint mobility due to the fact that the scar tissue that forms after healing often does not have the same mechanical properties of the original tissue. It is therefore very important to understand the mechanical response of tendons. In this paper the performances are examined of two viscoelastic standard nonlinear models in modelling the elastic and plastic behaviour of the tendon in the light of a well-known hyperelastic Yeoh model. The use of the Yeoh model is more for validating the performances of the viscoelastic models within the elastic region than for comparison purposes. The Yeoh model was selected based on its superior performance in modelling the elastic phase of soft tissue, as reported in previous studies, combined with its simplicity. The results show that the two standard nonlinear solid models perform extremely well both in fitting accuracies and in correlating stress results. The most promising result is the fact that the two standard nonlinear models can model tendon behaviour in the nonlinear plastic region. It is also noted that the two standard nonlinear models are physically insightful since their optimisation parameters can easily be interpreted in terms of tendon elasticity and viscoelastic parameters.

Application of Scanning Acoustic Microscopy for Detection of Dental Caries Lesion

Introduction: A scanning acoustic microscope (SAM) is an apparatus for imaging acoustic properties. This apparatus can non-invasively and rapidly evaluate the hardness of materials in the elastic region. This device shows great potential for the diagnosis of dental caries in the clinical setting. However, since the tissue elastic modulus measured using a SAM is a property of the elastic region and the Knoop hardness is a property of the plastic region, the hardness properties differ completely. Therefore, we investigated whether the acoustic impedance measured using a SAM is related to the Knoop hardness, which is used as the standard for removal of carious dentin. Method: Polished sections were prepared from 20 extracted carious wisdom teeth. The acoustic impedance and Knoop hardness were measured for each section. In addition to comparing carious and healthy dentin in SAM images, we evaluated the difference between the carious and healthy dentin in terms of the acoustic impedance and Knoop hardness. We also evaluated the correlation between the Knoop hardness and acoustic impedance. Results: The SAM images were visualized as two-dimensional color images based on the acoustic impedance values. The mean acoustic impedance of carious dentin was significantly lower than that of healthy dentin, showing a similar trend as Knoop hardness. A strong correlation was observed between the two. Discussion: The acoustic impedance values obtained through acoustic microscopy differed significantly between carious and sound dentin. Both types of dentins were visualized using two-dimensional color images. A strong correlation was observed between the acoustic impedance value, which indicates the hardness of the elastic region, and the Knoop hardness, which indicates the hardness of the plastic region. The results of the present study indicate that acoustic impedance accurately reflects the hardness of dentin.

마그네슘 합금 판재(AZ31B)의 인장 변형에서 AE 신호 발생 특성 분석

In this study, acoustic emission (AE) signals associated with the behavior of materials in the magnesium alloy (Mg AZ31B) tensile test were analyzed. The AE sensor was attached with the material to measure the AE signals. During the tensile experiment, the AE sensor measured the elastic waves generated inside the specimen. The AE parameters, such as, the signal energy, duration, and frequency centroid, were studied. We also analyzed the effect of the materials size and tensile speed on the AE signals. As a result, the lowest frequency centroid value occurred at the yield and fracture points. As the width and length of the specimen increased, the number of hit counts increased and the peak frequency occurred. Other AE parameters, such as, the duration and frequency centroid, were not affected. As the tensile speed increased, the hit decreased and the frequency centroid decreased in the elastic region. It was found that in the detection of the yield and fracture deformation, the number of counts, and frequency centroid were appropriate.

Solidification Microstructure and Mechanical Properties of B1-type TiC in Fe-Ti-C Ternary Alloys

The microstructure of the B1-type TiC formed during solidification and its mechanical properties were investigated using arc-melted Fe-Ti-C ternary alloys. The TiC formed at relatively high temperatures in the liquid as the primary phase exhibited a dendritic shape. With decreasing temperature and/or decreasing Ti and C content in the liquid, its morphology changed to a cubic shape with the {001}TiC habit plane, a plate shape with the {011}TiC habit plane, and a needle shape with the <001>TiC preferential growth direction. The morphology of the TiC was characterized by the anisotropy of its surface energy and its growth rate. The cubic shape with the {001}TiC habit plane was formed as a result of the minimum surface energy of the {001}TiC. However, the plate shape with the {011}TiC habit plane and the needle shape with the <001>TiC preferential growth direction should be formed due to the slowest growth rate of <011>TiC and the fastest growth rate of <001>TiC, respectively. At room temperature, alloy with the dendritic TiC was fractured in the elastic deformation region because the TiC exhibited no plastic deformation. On the other hand, at 800ºC, it was suggested that the TiC has plastic deformability and alloy with the dendritic TiC was also plastically deformed.

Similar Biomechanics Between the Double-Cortical Button and Docking Techniques for Ulnar Collateral Ligament Reconstruction: A Cadaveric Evaluation.

The docking technique is widely used to perform ulnar collateral ligament (UCL) reconstructions because of its high failure torque and reliable clinical outcomes. A double-cortical button technique was recently described, with advantages including the ability to tension the graft at the ulnar and humeral attachments and the creation of single bone tunnels. To compare the biomechanics between the docking and double-button UCL reconstruction techniques using cadaveric specimens. We hypothesized that there would be no difference in postoperative stiffness or maximum strength between the techniques. Controlled laboratory study. Eight matched pairs of cadaveric elbow joints underwent controlled humeral valgus torsion cycles in a test frame. Toe region stiffness, elastic region stiffness, and maximum torque were measured during a 4-step protocol: intact, injured, reconstructed (10 and 1000 cycles), and ramp to failure. Graft strains were calculated using 3-dimensional motion capture. After 10 cycles, intact ligaments from the docking and double-button groupsexhibited mean ± SD elastic torsional stiffness of 1.60 ± 0.49 and 1.64 ± 0.35 N·m/deg (P = .827), while docking (1.10 ± 0.39 N·m/deg) and double-button (1.05 ± 0.29 N·m/deg) reconstructions were lower (P = .754). There were no significant differences in maximum torque between the docking (3.45 ± 1.35 N·m) and double-button (3.25 ± 1.31 N·m) groups (P = .777). Similarly, differences in maximum graft strains were not significant between the docking (8.1% ± 7.2%) and double-button (5.5% ± 3.1%) groups (P = .645). The groups demonstrated similar decreases in these measures after cyclic loading. Ramp-to-failure testing showed no significant differences in ultimate torque between the docking (8.93 ± 3.9 N·m) and double-button (9.56 ± 3.5 N·m) groups (P = .739). The biomechanical behavior of the double-button technique was not significantly different from that of the docking technique. Both reconstruction techniques restored joint stability, but neither fully recapitulated preinjury joint stiffness. With its procedural advantages, results preliminarily support the use of the double-button reconstruction technique for UCL reconstruction as a reliable single-tunnel technique for primary or revision cases.

Experiment and atomistic simulation of uniaxial compression of Ni–W single-crystal alloy

The present work investigates the deformation behavior and identify the deformation relief patterns in Ni-28 W (28 wt. %W) single crystal under uniaxial compression using experimental and atomistic simulations. EAM (Embedded Atomic Method) potential is used for modelling the atomic interaction between Ni and W atoms. The compression test is carried at a constant temperature of 300 K and at a strain rate of 10-3 s−1 in experiment and 108 s−1 in atomistic simulation. Both experimental and simulation stress–strain curves show linear elastic region followed by strain hardening region till 20% strain and are in qualitative agreement. The observed slip lines can be seen inclined at an angle of 45° to the loading direction formed as a result of plastic deformation by slip on multiple slip systems in both experimental and simulated Ni–W single crystal alloy.

Flexible, Light-Interacting, B-Shaped Structures for Computations.

Integrating mechanical computing functions into robotic materials, microelectromechanical systems, or soft robotics can improve their intelligence in stimulation-response processes. Current mechanical computing systems exhibit limitations, including incomplete functions, unchangeable computing rules, difficulties in realizing random logic, and lack of reusability. To overcome these limitations, we propose a straightforward method of designing mechanical computing systems-based on the logic expressions-for complex computations. We designed soft, B-shaped mechanical metamaterial units, and compressed them to render stress inputs; the outputs are represented by the light-shielding effects caused by the unit deformations. We realized logic gates and corresponding combinations (including half/full binary adder/subtractor and addition/subtraction of 2 numbers with multiple bits) and provided a versatile solution for making a mechanical analog-to-digital converter to generate both ordered and disordered numbers. We performed all of the computations within the elastic regions of the B-shaped units; thus, after one computation, the systems can return to the initial states for reuse. The proposed mechanical computers will potentially enable robotic materials, microelectromechanical systems, or soft robotics to perform complex tasks. Furthermore, one can extend this concept to systems that are based on other mechanisms or materials.

REVIEW OF DYNAMIC PROPERTIES OF WOOD

This review considers the state of the art in the field of theoretical and experimental studies of dynamic deformation and destruction of wood materials. The orthogonal properties of wood, features of early and late wood are considered, the dynamic properties of wood are analyzed, as well as the influence of the strain rate during dynamic compression. It is noted that wood of different species is mainly used as one of the materials that dampen dynamic loads as a result of impacts or explosions. For example, it can mitigate the effects of high-velocity impacts on the contents of containers during the transport of hazardous materials by air, road and rail. It has been established that the cause of the effects of internal friction in wood are the areas of lignin, in which bundles of cellulose molecules (microfibrils) with a diameter of 25-30 nm are immersed, which are crystalline in their structure, which leads to viscoelastic behavior - internal damping. To improve the damping properties, it is recommended to choose wood with a low microfibril angle. It is noted that the stress-strain curve under dynamic compression of wood consists of three separate parts: the initial elastic region, the yield region and the compaction region. The main characteristics of compression, that is, the components of the stress-strain curve and the destruction of the fibers, do not depend on temperature. Young's modulus is much larger in the longitudinal direction than in the radial and tangential directions. The rate of deformation, temperature and humidity have a great influence on the strength properties of wood. The features of the mechanical behavior of the zones of early and late wood in the massif of a tree trunk are considered. Late wood is more rigid than early wood. As a result, differences in the mechanical properties of the wood fibers during compression may cause the early wood fibers to be destroyed while the late wood fibers remain intact. Due to the complexity of the wood structure, its reliable description by a numerical model requires complex models that take into account not only the influence of temperature, strain rate, and the type of stress-strain state, but also the angle between the direction of loading and the direction of wood fibers. Two main groups of wood material models are considered: micromechanical models simulating the details of the wood structure, and continuum models simulating the behavior of wood as a whole.

Modelling of the two-dimensional stresses in a three-layered adhesively bonded tungsten disulfide/poly(methyl methacrylate) nanocomposite structure under axial load

For the first time a two-dimensional stress-function method describing the stress transfer in a three-layered adhesively bonded tungsten disulfide/poly(methyl methacrylate) nanocomposite structure, subjected to axial load has been developed and applied. The governing fourth-order ordinary differential equation of with constant coefficients for the axial stress in the first layer has been obtained minimizing the strain energy in the whole structure and solved analytically. Depending of the sign of the discriminant of the respective characteristic equation of the 4th order differential equation for the considered nanocomposite structure, two different analytical solutions have been obtained for axial stress in the first layer. The type of solutions depends strongly from the geometry (length and thickness of the layers), material properties and magnitude of applied load. The two-dimensional stresses (axial, shear and peel) in the structure's layers are expressed and calculated as functions of this axial one and its derivatives and illustrated with three-dimensional graphics, for both solutions. The model results for axial stress in tungsten disulfide (WS2) were compared with shear–lag results and show good agreement in elastic region of applied tension load.

Finite Element Modeling of Cold-Formed Steel Bolted Moment Connection

This paper describes the finite element procedure for modeling cold-formed steel bolted moment connection to simulate hysteretic moment-rotation behavior and failure mode. The connection element consists of CFS curved flange beams, double-lipped channel columns, and trough plates. Abaqus software is used in this paper. The modeling procedure includes material properties, bolt modeling, boundary conditions, mesh, loading, and geometrical imperfections. The results of the finite element modeling were compared with the experimental test results in the form of a back-bone of the moment-rotation curve and a comparison of failure deformation. It was found that the finite element results had fairly good accuracy in predicting the hysteretic moment–rotation behavior. In the elastic region, the result shows that the finite element model successfully simulates the initial stiffness of the referenced beam-column connection. Meanwhile, the peak moment of the finite element model occurs at the same rotation as the experimental test but the magnitude of the peak moment is lower than the experimental result, which indicates that the finite element model produces a more conservative design. The comparison of failure deformation between finite element model and experimental test shows a very good agreement. The numerical model can simulate well the rotational behavior of the beam-column connection and can predict the general shape and location of local/distortional buckling at the beam-column connection.

Flexural behaviour of 3D-printed carbon fibre composites: Experimental and virtual tests - application to composite adaptive structure

Flexural properties of 3D-printed carbon fibre (CF) composites are investigated, experimentally and numerically. A series of 3-point bending experimental tests are conducted on CF composite specimens, and a series of 3-point bending virtual tests are simulated in LS-DYNA using a composite modelling approach, which is user defined integration points through the composite thickness. The flexural stress-strain results are compared, and they show good agreement within the elastic region. In the plastic region, the experimental flexural modulus reduces significantly, which remains constant for a certain range of flexural strain, before structural failure. A new hypothesis on the flexural properties of the 3D-printed CF composite is suggested, which is the specimen behaves as two stacks of individual beams, after yielding/delamination. The hypothesis is supported by another series of FE simulations on the composite, modelled as two stacked composite beams, and subjected to 3-point bending load. Then the capability of the composite 3D-printing to manufacture a structure with complex geometries and to manufacture several parts as a single structure, are exploited to fabricate a CF composite corrugated structure with a trailing edge section. The structure which represents an internal structure of a morphing aerofoil is actuated by a NiTi shape memory alloy (SMA) wire with a 1.6% recoverable strain. A trailing edge deflection of 6.0 mm is obtained, which is measured using an IMETRUM optical system. It is reasonably close to the predicted deflection of 7.3 mm shown in the FE simulation, using a newly developed UMAT for SMA-actuation, in an explicit LS-DYNA.