Search Results (150)

This study systematically investigates the piezoelectric performance of cement-based composite materials integrated with triply periodic minimal surface (TPMS) piezoelectric ceramic architectures, including Schwarz P and Neovius structures, in comparison with conventional 0–3 and 1–3 connectivity models. Under mechanical loading conditions, finite element analysis was employed to evaluate the average piezoelectric coefficients, voltage coefficients, and potential outputs of composites with varying piezoelectric ceramic volume fractions. Key findings reveal that the Neovius structure exhibits superior performance: at a 20% ceramic volume fraction, its average piezoelectric coefficient reaches 116 pC/N under 15 kN loading, surpassing the 0–3 type by approximately 12-fold. Both Schwarz P and Neovius structures demonstrate approximately 12× higher average piezoelectric coefficients than the 0–3 model, attributed to their continuous charge transfer pathways and efficient stress distribution enabled by TPMS geometry. Additionally, the piezoelectric voltage coefficients of TPMS-based composites significantly exceed those of traditional 1–3 and 0–3 structures. The potential generation capacity of Neovius composites peaks at 6.7 V under high loading, highlighting their superiority in charge accumulation. The results underscore the critical role of piezoelectric ceramic architecture: the bicontinuous TPMS configurations mitigate phase discontinuity issues, enhancing both mechanical–electrical coupling and energy conversion efficiency. This study provides a novel framework for optimizing cement-based piezoelectric composites toward applications in structural health monitoring, energy harvesting, and smart infrastructure. Full article

With the expansion of offshore oil and gas resources to deepwater areas, the problem of the vortex-induced vibration of marine risers, as a key structure connecting offshore platforms and subsea wellheads, has become increasingly prominent. At present, there are few reviews on the vortex-induced vibration of flexible risers. This review provides a detailed discussion of vortex-induced vibration in marine risers. This review begins with the engineering background. It then systematically analyzes the key factors that influence VIV response. These factors include the riser’s structural parameters, such as aspect ratio and mass ratio. They also include the external fluid environment. Next, this review evaluates current VIV suppression strategies by analyzing specific experimental results. It compares the effectiveness and trade-offs of passive techniques. It also examines the potential and limitations of active methods, which often use smart materials, like piezoelectrics. This study highlights the major challenges in VIV research today. These challenges relate to prediction accuracy and suppression efficiency. Key problems include model uncertainty at high Reynolds numbers and the practical implementation of suppression devices in engineering systems. Finally, this paper presents an outlook on the future directions. It concludes that an intelligent, full-lifecycle integrity management system is the best path forward. Full article

The increasing demand for light and comfort smart wearable devices has promoted the cross-integration of textile technology with nanomaterials and nanotechnology. As a potential candidate with excellent piezoelectricity, PVDF has been processed into different forms used for flexible sensors but shows limited practicality due to their discomfort and stiffness from non-yarn level. In this study, PVDF/BN nanofiber yarns (NFYs) were successfully fabricated via conjugated electrospinning. The effects of BN concentration, stretching temperature, and stretching ratio on the structural morphology and mechanical performance of the NFYs were systematically investigated. The results show that under the stretching temperature of 140 °C and stretching ratios of 3.5, smooth 1% PVDF/BN NFYs with highly oriented inner nanofibers can be successfully fabricated, and the breaking strength and elongation of composite NFYs reached 129.5 ± 8.1 MPa and 22.4 ± 3.8%, respectively, 667% higher than the breaking strength of pure PVDF nanoyarns. Hence, with the selection of appropriate nanofiller amounts and optimized post-treatment process, the structure and mechanical property of PVDF NFYs can be significantly improved, and this study provides an effective strategy to fabricate high-performance nanoyarns, which is favorable to potential applications in wearable electronic devices and flexible piezoelectric sensors. Full article

Bridges play a key and controlling role in transportation systems. Steel bridges are favored for their high strength, good seismic performance, and convenient construction. As important node connectors of steel bridges, high-strength bolts are extremely susceptible to damage such as corrosion and loosening. Therefore, accurate identification of bolt loosening is crucial. First, a new type of adhesive piezoelectric sensor is designed and prepared using PMN-PT piezoelectric single-crystal materials. The PMN-PT sensor and polyvinylidene fluoride (PVDF) sensor are subjected to steel plate fixed frequency load and swept frequency load tests to test the performance of the two sensors. Then, a steel plate component connected by high-strength bolts is designed. By applying exciter square wave load to the structure, the vibration response characteristics of the structure are analyzed to identify the loosening of the bolts. In addition, a piezoelectric smart washer sensor is designed to make up for the shortcomings of the adhesive piezoelectric sensor, and the effectiveness of the piezoelectric smart washer sensor is verified. Finally, a bolt loosening index is proposed to quantitatively evaluate the looseness of the bolt. The results show that the sensitivity of the PMN-PT sensor is 21 times that of the PVDF sensor. Compared with the peak stress change, the natural frequency change is used to identify the bolt loosening more effectively. Piezoelectric smart washer sensor and bolt loosening indicator can be used for bolt loosening identification. Full article

This study proposes a piezoelectric device for vibration damping in satellite solar panels. The design features a structural arrangement with piezoelectric stacks configured in a V-shape and hinged to the main yoke structure. The satellite structure is modeled using an Euler–Bernoulli beam finite element framework, incorporating the electro-mechanical coupling of active elements through equivalent nodal piezoelectric loads. Various shunt circuits are designed to mitigate vibrations, with a parametric study conducted to optimize the key circuit parameters. Additionally, a filtered PID active suppression system is developed and tuned using a meta-heuristic algorithm to determine optimal controller gains. Numerical simulations are performed to evaluate and compare the effectiveness of the proposed vibration suppression systems, demonstrating the efficiency of the smart structure configuration and providing performance analysis. Full article

The continuous evolution of aerospace technology has intensified the demand for innovative materials that enhance structural performance, fuel efficiency, and operational safety. This study conducts systematic bibliometric analysis using data from Scopus and the Web of Science, covering publications from the last decade. Smart composites have emerged as a transformative class of materials, integrating structural health monitoring (SHM), electromagnetic interference (EMI) shielding, and multifunctional capabilities such as self-sensing, self-healing, responsiveness to external stimuli, and adaptability to environmental conditions. Recent developments focus on nanotechnology, the additive manufacturing of smart materials, piezoelectric materials and sensors, as well as aerogels and ultralight structures. By analyzing the evolution of scientific contributions and identifying knowledge gaps, this review provides a valuable resource for guiding future advancements in smart composite materials for aerospace engineering. Full article

The design of piezoelectric roads is one of the future directions of smart roads. In order to ensure the environmentally friendly and long-lasting use of piezoelectric road materials, lead-free piezoelectric ceramics (barium titanate), polymer piezoelectric materials (polyvinylidene fluoride), and conductive particles (conductive carbon black and graphene) were used to prepare composite piezoelectric materials. The electrical performance was studied by the conductivity, dielectric properties, and piezoelectric properties of the composite materials. Then, the mechanical properties of the composite material were investigated by load compression tests. Finally, the microstructure of the composite materials was studied. The results showed that as the amount of conductive particles increased, the electrical performance was improved. However, further addition of conductive particles led to a decline in the electrical performance. The addition of conductive particles had a minimal effect on the mechanical properties of composite materials. The composite material met road use requirements. The overall structure of the composite materials was compact, with a clear wrapping effect of the polymer, and good interface compatibility. The addition of conductive carbon black and graphene had no significant impact on the structure of the composite materials. Full article

This review explores the integration of polymer materials into piezoelectric composite structures, focusing on their application in sensor technologies, and wearable electronics. Piezoelectric composites combining ceramic phases like BaTiO₃, KNN, or PZT with polymers such as PVDF exhibit significant potential due to their enhanced flexibility, processability, and electrical performance. The synergy between the high piezoelectric sensitivity of ceramics and the mechanical flexibility of polymers enables the development of advanced materials for biomedical devices, energy conversion, and smart infrastructure applications. This review discusses the evolution of lead-free ceramics, the challenges in improving polymer–ceramic interfaces, and innovations like 3D printing and surface functionalization, which enhance charge transfer and material durability. It also covers the effects of radiation on these materials, particularly in nuclear applications, and strategies to enhance radiation resistance. The review concludes that polymer materials play a critical role in advancing piezoelectric composite technologies by addressing environmental and functional challenges, paving the way for future innovations. Full article

In recent years, civil engineering has increasingly embraced communication tools for automation, with sensors playing a pivotal role, especially in structural health monitoring (SHM). These sensors enable precise data acquisition, measuring parameters like force, displacement, and temperature and transmit data for timely interventions to prevent failures. This approach reduces reliance on manual inspections, offering more accurate outcomes. This review explores various sensor technologies in SHM, such as piezoelectric, fibre optic, force, MEMS devices, GPS, LVDT, electromechanical impedance techniques, Doppler effect, and piezoceramic sensors, focusing on advancements from 2019 to 2024. A bibliometric analysis of 1468 research articles from WOS and Scopus databases shows a significant increase in publications, from 15 in 2019 to 359 in 2023 and 52 in 2024 (and still counting). This analysis identifies emerging trends and applications in smart sensor integration in civil and structural health monitoring, enhancing safety and efficiency in infrastructure management. Full article

Two identically sized RC beams were fabricated to investigate the effects of explosive loads on the flexural behaviour of Reinforced Concrete (RC) beams. One of the beams was subjected to an explosive load to induce post-explosion damage, and subsequently, both beams underwent flexural capacity testing. Integrating piezoelectric smart aggregates (SAas) within the beams facilitated continuous observation of the damage conditions, allowing for the assessment of internal concrete deterioration from explosive impacts to bending failures. The internal crack development index R was established using the Wavelet Packet Energy Analysis method. Combined with the structure’s residual capacity-based damage assessment criterion, the relationship between R and component damage was found. This allowed us to identify the change in the bending capacity of RC beams after explosion damage and the quantitative damage assessment of the beam to be realised, providing valuable insights for structural engineers and researchers. Comparing the flexural test results between the explosively pre-damaged beam and the undamaged test beam, it was observed that the neutral axis of the damaged beam was significantly elevated, accompanied by a notable reduction in flexural capacity. By examining the variation curve of the internal crack development index R, it was noted that during the initial stage of the bending flexural test, due to bending deformation, cracks in the core region of the pre-damaged beam gradually healed, leading to a pseudo-decrease in the damage index. After reaching a minimum point, the damage progressed faster until failure occurred. Full article

Ultrasonic pulse velocity (UPV) has shown effectiveness in determining the depth of surface-open cracks in concrete structures. The type of transducer and the algorithm for extracting the arrival time of the ultrasonic signal significantly impact the accuracy of crack depth detection. To reduce the energy loss in piezoceramic-based sensors, a high-performance piezoceramic-enabled smart aggregate (SA) was employed as the ultrasonic transducer. For the extraction of ultrasonic signal arrival time in concrete, a novel characteristic equation was proposed, utilizing the slope of the signal within a shifting window. This equation was subsequently applied to modify Maeda’s function, with the arrival time of ultrasonic waves defined as the moment corresponding to the minimum Akaike information criterion (AIC) value. Six plain concrete specimens with artificial cracks were prepared and one reinforced concrete beam with a load-induced crack was used for validation. The average deviation of the testing of 492 points on 12 human-made cracks was around 5%. The detection results of 11 measurement points of a crack in a reinforced concrete beam show that three measurement points have a deviation of about 17%. The experimental results demonstrated that the novel piezoelectric transducer and improved AIC algorithm exhibit high accuracy in detecting the depth of concrete cracks. Full article

Vibration is a major problem that can cause structures to wear out prematurely and even fail. Smart structures are a promising solution to this problem because they can be equipped with actuators, sensors, and controllers to reduce or eliminate vibration. The primary objective of this paper is to explore and compare two deep learning-based approaches for vibration control in cantilever beams. The first approach involves the direct application of deep learning techniques, specifically multi-layer neural networks and RNNs, to control the beam’s dynamic behavior. The second approach integrates deep learning into the tuning process of a PID controller, optimizing its parameters for improved control performance. To activate the structure, two different input signals are used, an impulse signal at time zero and a random one. Through this comparative analysis, the paper aims to evaluate the effectiveness, strengths, and limitations of each method, offering insights into their potential applications in the field of smart structure control. Full article

Advancements in wearable technology and lab-on-chip devices necessitate improved integrated microflow pumps with lower driving voltages. This study examines a piezoelectric pump using a flexible β-phase copolymer poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) film. Six samples (S1–S6) were fabricated and subjected to a three-step annealing process to optimize their properties. Characterization was conducted via atomic force microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, impedance analysis, and polarization hysteresis loop measurements. The results show that annealing at approximately 135 degrees Celsius produces a β-phase structure with uniform “rice grain”-like crystallites. A microfluidic pump with a nozzle/diffuser structure, using S4 film as the drive layer, was designed and manufactured. Diaphragm deformation and pump performance were assessed, showing a maximum water flow rate of 25 µL/min at 60 Hz with a peak-to-peak voltage (V_pp) of 60 V. The flow rate could be precisely controlled within 0–25 µL/min by adjusting the V_pp and frequency. This study effectively reduced the driving voltage of the piezoelectric pump, showing that it has significant implications for smart wearable devices. Full article

In recent years, vibration control utilizing smart materials has garnered considerable attention. In this paper, we aim to achieve vibration suppression of a plate structure with a tail-fin shape by employing piezoelectric actuators—one of the smart materials. The plate structure is rigorously modeled based on the Kirchhoff–Love plate theory, while the piezoelectric actuators are formulated in accordance with the Prandtl–Ishlinskii model. This research proposed a control system that addresses the interference effects arising during vibration control by dividing multiple piezoelectric elements into two groups and implementing MIMO control. The efficacy of the proposed control method was validated through simulations and experiments. Full article

In this study, we introduce progress in intelligent control for reducing structural vibrations. The field of intelligent control for dampening structural vibrations is evolving rapidly, driven by advancements in materials science, AI, and actuator technology. These innovations have led to more efficient, reliable, and adaptable vibration-control systems with applications ranging from civil engineering to aerospace. The use of smart materials has opened new avenues for vibration control of piezoelectric materials. When mechanical stress is applied to these materials, an electric charge response is formed, allowing for precise control over the vibrations. Improved computational models and simulations play crucial roles in the design and testing of vibration-control systems. Finite element analysis helps in accurately predicting the behavior of structures under various loads, thereby aiding in the design of effective vibration-control systems. In our work, we use intelligent control theory to dampen structural vibrations in engineering structures. Full article