Development Of Smart Structures Research Articles

Building information modeling (BIM) driven performance-based construction for the optimization of sustainable and smart structures development

Given the escalating apprehensions regarding climate change and environmental risks, the construction industry is confronted with the crucial task of guaranteeing the enduring structural robustness of buildings. Building Information Modeling (BIM) has emerged as an innovative tool to tackle these challenges effectively and enhance the performance of building structures processes by developing intelligent and sustainable structures. A comprehensive methodology was utilized to assess the relationships between the BIM factors and their impacts on smart and sustainable structure development by conducting a literature overview, quantitative analysis, exploratory factorial analysis (EFA), structural equation modeling (SEM), and predictive relevance findings. The findings show positive correlations between the implementation of BIM and the elements integral to smart and sustainable structure development. This study investigates the effects of BIM-driven environmental risk assessment, BIM-enabled energy efficiency, environmental performance, climate change adaptation strategies with BIM, and real-time monitoring and maintenance on the effectiveness of smart and sustainable structures development. The BIM-driven environmental risk assessment significantly impacts the sustainable and smart structures development with B = 0.360, followed by the real-time monitoring and maintenance with BIM with 0.316. This study provides the contemporary knowledge base by providing insights into BIM's transformative abilities in shifting sustainable and smart construction practices. The outcomes offer widespread insights to enterprise specialists interested in enhancing task effects and organizing sustainable and environmentally aware built surroundings. The growing popularity of BIM has implications for the future growth of the construction industry in phrases of ecologically smart and sustainable structure development.

Development of Fiber-Bragg-Grating-Integrated Artificial Embedded Tendon for Multifunctional Assessment of Temperature, Strain, and Curvature.

This paper presents the development and application of an optical fiber-embedded tendon based on biomimetic multifunctional structures. The tendon was fabricated using a thermocure resin (polyurethane) and the three optical fibers with one fiber Bragg grating (FBG) inscribed in each fiber. The first step in the FBG-integrated artificial tendon analysis is the mechanical properties assessment through stress-strain curves, which indicated the customization of the proposed device, since it is possible to tailor the Young's modulus and strain limit of the tendon as a function of the integrated optical fibers, where the coated and uncoated fibers lead to differences in both parameters, i.e., strain limits and Young's modulus. Then, the artificial tendon integrated with FBG sensors undergoes three types of characterization, which assesses the influence of temperature, single-axis strain, and curvature. Results show similarities in the temperature responses in all analyzed FBGs, where the variations are related to the heterogeneity on the polyurethane matrix distribution. In contrast, the FBGs embedded in the tendon presented a reduction in the strain sensitivity when compared with the bare FBGs (i.e., without the integration in the artificial tendon). Such results demonstrated a reduction in the sensitivity as high as 77% when compared with the bare FBGs, which is related to strain field distributions in the FBGs when embedded in the tendon. In addition, the curvature tests indicated variations in both optical power and wavelength shift, where both parameters are used on the angle estimation using the proposed multifunctional artificial tendon. To that extent, root mean squared error of around 3.25° is obtained when both spectral features are considered. Therefore, the proposed approach indicates a suitable method for the development of smart structures in which the multifunctional capability of the device leads to the possibility of using not only as a structural element in tendon-driven actuators and devices, but also as a sensor element for the different structures.

Recent Research Developments of 4D Printing Technology for Magnetically Controlled Smart Materials: A Review

Traditional printed products have to some extent affected the development of smart structures and their application in multiple fields, especially in harsh environments, due to their complex mechanisms and control principles. The 4D printing technology based on magnetically controlled smart materials exploits the advantages of magnetically controlled smart materials with good operability and security, and its printed smart structures can be obtained under magnetic field drive for unfettered remote manipulation and wireless motion control, which expands the application of printed products in complex environments, such as sealed and narrow, and has broad development prospects. At present, magnetically controlled smart material 4D printing technology is still in its infancy, and its theory and application need further in–depth study. To this end, this paper introduces the current status of research on magnetically controlled smart material 4D printing, discusses the printing process, and provides an outlook on its application prospects.

Initial proposal of a smart cement-based material to enhance the service-life of reinforcement concrete structures

The sustainable development of societies can be pursued by simultaneously avoiding the depletion of materials and resources and reducing the greenhouse gases emissions, with related climatic change effects. In order to get this, the extension of structures service-life plays a significant role in saving natural resources, decreasing the overall anthropogenic carbon-footprint, and reducing building and demolition wastes. In order to achieve such prolongation of structures service-life, one of the most promising approaches is the development of Smart Structures. These are defined as structures that are able to self-sense some external stimuli such as stress or temperature variations, and internal conditions such as chloride penetration, concrete carbonatation, etc. Consequently, ongoing damage phenomena can be detected promptly, thus allowing to implement suitable countermeasures in the most efficient way. Smart Structures can also process the information and respond autonomously in real time by using smart materials technologies such as self-healing technology. In this study we propose a preliminary version of a smart material system with self-healing and sensing properties, to demonstrate its effectiveness at a proof of concept level. The effectiveness of an active, capsule-based self-healing system in blocking chloride penetration through the crack and the effectiveness of voltametric Ag sensors in detecting the presence of chlorides were investigated experimentally. High-performance cement mortar was chosen as the material to be studied, in order to ensure that optimal behaviour could be observed in non-cracked conditions.

Effect of Adhesive Layer Thickness and Slant Angle on Piezoelectric Bonded Joints

Piezoelectric materials have found their parts in numerous manufacturing applications such as transducers and sensors. Piezoelectric material shows anisotropy; in addition, its elastic field and electric field are integrated. The analysis of piezoelectric materials has obtained great interest among researchers with the development of smart structures. It is significant to explain the distribution of stress and electric displacement fields along the bonded edge. It has never been obvious how stress singularity and electric displacement fields are distributed at the vertex of piezoelectric dissimilar material joints. Stress and electric displacement distribution near the vertex along the interface of piezoelectric boned joints are investigated in this present research. Numerical analysis of piezoelectric dissimilar material joints is carried out by using Abaqus FEA software. From the numerical analysis, it is observed that stress, displacement, electric potential, electric displacement field evolvement along the interface edge rises with the increment of adhesive layer thickness and slant angle. So, a thin adhesive layer thickness and small slant angle are more reliable for operation.

Flexural Models for Vacuum-Packed Particles as a Variable-Stiffness Mechanism in Smart Structures

Vacuum-packed particle (VPP) systems have been recently used in the development of smart structures due to their ability to actively change material stiffness through the mechanism of granular jamming. By altering the strength of the vacuum pressure applied to the particles, the material can be proportionally and reversibly transitioned from a liquidlike low-stiffness state to a stiff state. The ability to control material stiffness in this way opens up different possibilities for the design of morphing and smart structures by allowing them to soften during deformation to reduce actuation energy requirements and to then stiffen once the desired shape has been achieved to provide a zero-energy holding mechanism. The following research describes two useful models that predict the mechanical response of VPP beams under flexural loading. Firstly, four-point bending tests with digital image correlation strain mapping are performed in order to measure the axial and transverse strains in a bending beam made from vacuum-packed particles. The test results show a nonlinear mechanical response, including a change in beam thickness with deformation, that motivated an analytical model of the structure incorporating a nonlinear material stress model based on the Mohr-Coulomb failure envelope. In addition, finite-element simulations are implemented using a Johnson-Cook model extension to predict the response under loading of three-dimensional beam elements at different vacuum pressure levels. Lastly, the models are compared to the experimental results, indicating good agreement. Both methods are shown to be useful for predicting the variation of stiffness of vacuum-packed particle beams.

A Review Of Utilizing Shape Memory Alloy In Structural Safety

Abstract- The advancement of material technology has paved the way for smart materials to emerge in the civil engineering sector. These smart materials possess the potential to encounter structural deterioration. Therefore, proper attention should be provided to smart materials regarding both research and application. Shape memory alloy (SMA) is a unique smart material that demonstrates growing applicability in numerous sectors. Recently, a lot of emphasis is being given to SMA research with a view to utilizing SMA in civil engineering structures. SMAs have some special properties such as high damping capacity, self-centering mechanism, two-way memory, self-adaptability etc. for which they can be used to make various types of structural control devices. An integrated assessment of the fundamental properties of SMAs, based on the existing data is presented by this paper in a concise and graphical manner. This paper also discusses the possibility of implementing SMAs in a wide range of civil engineering application, therefore motivating the large scale development of smart structures.

Higher-order resistivity-strain relations for self-sensing nanocomposites subject to general deformations

Nanocomposites have received enormous attention for the development of smart structures and materials with intrinsic self-sensing capabilities via the piezoresistive effect. Consequently, much work has been done to model the resistivity-strain relationship in these materials. To date, the prevailing approach to modeling nanocomposite piezoresistivity has been to track the interaction of individual nanofillers via computational micromechanics-based models or analytical homogenizations thereof. Even though such models have generated great insight into the piezoresistive effect, they are not without limitations. For example, they are computationally expensive, require extensive calibration and/or training data, and are often limited to simple deformations and microscale analyses. In light of the preceding, this work presents a novel higher-order tensor-based resistivity-strain relation that is amenable to general strains and macroscale analyses. Herein, it is shown that higher-order resistivity-strain relations can be described by three piezoresistive constants which can be determined by fitting the model to experimental data. The proposed resistivity-strain relation is applied to three different weight fractions of carbon nanofiber (CNF)-modified epoxy and validated against experimental discrete resistance changes and spatially distributed resistivity changes imaged via electrical impedance tomography (EIT) for complex strain states with good agreement. This work could be of significant impact to a wide range of engineers working with polymer, cementitious, and ceramic-based smart materials who wish to utilize the piezoresistive effect without resorting to in-depth microscale modeling.

Damage Identification in Structural Health Monitoring: A Brief Review from its Implementation to the Use of Data-Driven Applications.

The damage identification process provides relevant information about the current state of a structure under inspection, and it can be approached from two different points of view. The first approach uses data-driven algorithms, which are usually associated with the collection of data using sensors. Data are subsequently processed and analyzed. The second approach uses models to analyze information about the structure. In the latter case, the overall performance of the approach is associated with the accuracy of the model and the information that is used to define it. Although both approaches are widely used, data-driven algorithms are preferred in most cases because they afford the ability to analyze data acquired from sensors and to provide a real-time solution for decision making; however, these approaches involve high-performance processors due to the high computational cost. As a contribution to the researchers working with data-driven algorithms and applications, this work presents a brief review of data-driven algorithms for damage identification in structural health-monitoring applications. This review covers damage detection, localization, classification, extension, and prognosis, as well as the development of smart structures. The literature is systematically reviewed according to the natural steps of a structural health-monitoring system. This review also includes information on the types of sensors used as well as on the development of data-driven algorithms for damage identification.

Shape Memory Alloys and their Thermal Characteristics

The smart structures are sometimes called “intelligent” or “adaptive” structures, being a class of advanced structures having highly distributed actuators and sensors combined with structural functionality, distributed control functions and even computing architectures. The structures are able to vary their geometric configurations as well as their physical characteristics subject to control laws. These include piezoelectric, electrostrictives, magnetostrictives, ionic polymers, Shape Memory Alloys (SMA), and magnetic shape memory alloys (MSMAs). Development of smart structures involves the integration of active and passive material systems, often including the coupling of relevant mechanical, electrical, magnetic, thermal, or other physical properties. This can subject the active materials to large stress levels, cyclic loads, thermal loads, or environmental loads that result in non-linear responses and large variations in material properties. Smart materials are not only singular materials; rather, they are also hybrid composites or integrated systems of materials. Shape memory alloys (SMAs) are one of the major elements of smart hybrid composites because of their unique properties, such as shape memory effect, pseudo elasticity and high damping capacity. These properties in smart hybrid composites provide tremendous potential for creating new paradigms for material – structural interactions and demonstrate various successes in many engineering applications, such as vibration control, actuators in MEMS, and a variety of others.

An efficient method for solving the MAS stiff system of nonlinearly coupled equations: Application to the pseudoelastic response of shape memory alloys (SMA)

A Shape memory alloy (SMA) actuators have great potential in advanced technology applications where space, weight and cost are crucial design factors. They are known for the shape memory effect which is the ability to recover an initial configuration by simple heating after deformation. SMAs also exhibit a behavior called "pseudoelasticity" also known as "superelasticity" which is the shape recovery associated with mechanical loading and unloading at temperatures above specific values. The key characteristic of SMAs is the martensitic phase transformation, brought about by temperature change and/or by application of stress. Martensitic transformation is usually accompanied by significant changes in mechanical, electrical and thermal properties that render them as prime candidates for the development of smart structures and devices. This work is a contribution to the study of the influence of parameters such as operating temperature and the mode of heat transfer (natural or forced convection) on the pseudoelastic response of SMA used as actuators. Based on the mathematical formalism of the Müller, Achenbach and Seelecke model known as the "MAS model", we develop through a new mathematical formalism a new iterative resolution methodology of the coupled equations. The new approach provides very significant results and allows a significant gain in computation time.

Smart behaviour of layered plates through the use of auxetic materials

The development of smart structures, aimed at optimizing the response of engineering systems, is a modern and very promising field. Such advanced structural element can be obtained, in some cases, by using the so-called auxetic materials, i.e. materials exhibiting negative Poisson׳s ratio. In the present paper a brief introduction on auxetic materials and on their use and potentiality is presented. In particular their application to obtain smart layered plates is discussed; it is shown as these materials allow, in certain conditions, to get a desired stiffness and a nearly linear behaviour (even under large displacement conditions) of bended plates, without changing the plate׳s geometry and materials. Such potentialities are presented and discussed based on numerical analyses, and a mechanical interpretation of the observed structural behaviour is proposed.

Optimal feedback design for nonlinear stochastic systems using the pseudospectral method

The development of smart structures involves the use of various types of controllable damping devices by integrating them into structural systems for energy dissipation. An optimal feedback control law that can consider the nonlinearity embedded in the systems and the random characteristics of the external inputs is desirable to control such dissipation mechanism. This paper proposes an innovative numerical technique to obtain the optimal feedback control strategy of nonlinear stochastic systems. The systems under investigation are modeled as mechanical oscillators and a damping device. The numerical approach proposed to obtain the optimal control strategy involves solving a nonlinear partial differential equation—the Hamilton–Jacobi–Bellman equation. Because civil engineering structural systems may exhibit nonlinear hysteretic behavior under extreme loading conditions, the application of the obtained control strategy could provide an optimal feedback control law to reduce the system response under random excitations (such as earthquakes, wind load and sea waves). Several numerical examples are presented to verify optimality and demonstrate the efficacy of the proposed optimal control solution. First, a linear oscillator is used to verify that the obtained solution is indeed the optimal solution by comparing it to the closed-form optimal solution. Then the proposed method is applied to several nonlinear systems. In each nonlinear example, control optimality is demonstrated by comparing the system responses and control costs obtained using the proposed optimal controls with those obtained using corresponding linearized optimal controls.

Response surface methodologies for coupling factor exploration: an application example for noise reduction by means of smart structures

The development of smart structures requires methods to explore the behavior of electromechanical systems. Engineers must take into account various interactions between particular system parameters and the system’s responses. A variety of mathematical models is used to describe the system behavior depending on defined design variables. Based on the mathematical models, system analyses and optimization procedures can be performed. All suitable methods can be summarized as design exploration. This paper describes four mathematical models, their application in design exploration and the resulting differences. The mathematical models are linear interpolation, full second-order polynomials, Kriging interpolation and genetic programming. As an application example a smart thin curved plate is presented. The importance of the electromechanical coupling factor, which is used as the system response considered in this paper, for noise reduction by means of smart structures is pointed out.

Strain Analysis of Surface Bonded Optical Fiber Sensors

Optical fiber sensors with light weight, small size and immunity to electromagnetic interference have been found to be a promising device for use in the development of smart structures. It is well known that the strain transfer from the host structure to the optical fiber sensor is dependent on the bonding characteristics such as adhesive layer and bonded length. In this investigation, the optical fiber sensor is surface bonded on the host structure. A theoretical model consisting of the optical fiber, adhesive layer and host material, is proposed to determine the strain in the optical fiber sensor induced by the host structure. The theoretical predictions were validated with the numerical analysis using the finite element method.

A fully‐coupled nonlinear thermoelectromechanical model for piezolaminated smart structures

AbstractIn present engineering applications piezoelectric materials gain increasing importance in the development of smart structures; e.g., for shape and vibration control problems. Such structures exhibit a three‐way coupling effect between the mechanical, electrical and thermal quantities. In the majority of papers available in literature this coupling is taken into account only in the constitutive equations. It is however well known that truly coupled analysis should also be based on the interaction of the mechanical, thermal and electrostatic quantities in the field equations. Only in this way many physical effects can be taken into account; e.g., the strain rate dependant change of temperature due to mechanical loading. Furthermore most of the analyses conducted in this area are performed in the linear range of deformations assuming small strains, rotations and temperature changes. However smart technology is generally applied to thin walled structures and in many cases reported in literature the deflections are much larger than the thickness, which results into geometrically nonlinear behaviour, like e.g. the occurrence of stress stiffening which greatly affects the prediction of sensor voltage outputs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Transient Thermal Fracture Analysis of Transversely Isotropic Magneto-Electro-Elastic Materials

Modern materials such as magneto-electro-elastic materials are used in the development of smart structures. The magneto-electro-elastic materials possess the dual features that the application of electric field induces magnetization and magnetic field induces electric polarization. The theory of linear magneto-electro-elasticity is applied to solve transient thermal fracture in magneto-electro-elastic cylinder under sudden heating on its outer surface. The equilibrium equations are obtained from the constitutive equations. The governing partial differential equations are deduced by using equilibrium equations of elastic, electric and magnetic fields. The heat conduction equation is solved by separation of variable technique. Hankel transform is applied to solve elastic displacements, electric potential and magnetic potential. The problem is reduced into integral equation involving Bessel functions which is treated exactly using Abel's integral equation. Transient distributions of temperature, stress, displacement and magnetic inductions are derived for magneto-electro-elastic cylinder. Thermal stress, electric displacement and magnetic induction-intensity factors are obtained. The solutions are valid for both impermeable and permeable crack models. The studies are valuable for such material analysis and design.

Optimal design in vibration control of adaptive structures using a simulated annealing algorithm

Advanced reinforced composite structures incorporating piezoelectric sensors and actuators are increasingly becoming important due to the development of smart structures. These structures offer potential benefits in a wide range of engineering applications such as vibration and noise suppression, shape control and precision positioning. This paper presents a finite element formulation based on the classical laminated plate theory for laminated structures with integrated piezoelectric layers or patches, acting as sensors and actuators. The finite element model is a single layer triangular nonconforming plate/shell element with 18 degrees of freedom for the generalized displacements, and one additional electrical potential degree of freedom for each surface bonded piezoelectric element layer or patch. The control is initialized through a previous optimization of the core of the laminated structure, in order to minimize the vibration amplitude and maximize the first natural frequency. Also the optimization of the patches position is performed to maximize the piezoelectric actuators efficiency. The simulated annealing algorithm is used for these purposes. To achieve a mechanism of active control of the structure dynamic response, a feedback control algorithm is used, coupling the sensor and active piezoelectric layers or patches, and to calculate the dynamic response of the laminated structures the Newmark method is considered. The model is applied in the optimization of an illustrative adaptive laminated plate case. The influence of the position and number of piezoelectric patches, as well as the control gain, are investigated and the results are presented and discussed.

1703 銅メッキ電極を用いた電気抵抗変化法によるCFRP厚板のはく離検知(J08-1 材料モニタリング,損傷検知・抑制,J08 知的材料・構造システム)

Detection of damages for composites is a difficult task for visual inspections. The difficulty of detections causes the importance of development of smart structures for monitoring damages of graphite/epoxy laminated composites. In our previous study, the applicability of the damage identification using an electrical resistance change method for laminates has been confirmed. Making procedure of electrode is important in adopting the electrical resistance change method for practical structures. Silver paste electrode used in the previous study had, however, low adhesion strength and complex making procedure. In the present study, we focused on the electrical copper plating. Twelve electrodes made by electrical copper plating are mounted on the quasi-isotropic CFRP thick plates surface, and the electrical resistance changes are measured using a conventional strain gage amplifier. Furthermore, adhesion strength of electrode was measured. As a result, efficiency of electrical copper plating electrode was confirmed experimentally.

Real-time nondestructive evaluation of fiber composite laminates using low-frequency Lamb waves.

Amid the nondestructive evaluation techniques available for the inspection of composite materials, only a few are suitable for implementation while the component is in service. The investigation examines the application of Lamb waves at low-frequency-thickness products for the detection of delaminations in thick composite laminates. Surface-mounted piezoelectric devices were excited with a tone burst to generate elastic waves in the structure. Experiments were carried out on composite beam specimens where wave propagation distances over 2 m were achieved and artificially induced delaminations as small as 1 cm2 were successfully identified. The feasibility of employing piezoelectric devices for the development of smart structures, where a small and lightweight transducer system design is required, has been demonstrated. The resonance spectrum method, which is based on the study of spectra obtained by forced mechanical resonance of samples using sine-sweep excitation, has been proposed as a technique for measuring the A0 Lamb mode phase velocity. The finite-element method was also used to investigate qualitatively the dynamic response of laminates to wave propagation. Several locations and spatial distribution of the actuators were examined showing the advantages of using transducers arrays for the inspection of large structures.