Composite Structures最新文献

{"title":"Temperature-dependent stiffness of a composite wind turbine blade: experimental investigation at material and structural scales","authors":"Przemysław Kalitowski,&nbsp;Arkadiusz Jenta,&nbsp;Agnieszka Tomaszewska,&nbsp;Marcin Krajewski,&nbsp;Michał Wójcik,&nbsp;Beata Zima","doi":"10.1016/j.compstruct.2026.120682","DOIUrl":"10.1016/j.compstruct.2026.120682","url":null,"abstract":"<div><div>Operation of wind turbines in cold climates involves substantial temperature variations that may affect the mechanical behaviour of composite blades and thereby interfere with structural health monitoring and digital twin applications if not properly accounted for. This study investigates the influence of sub-zero temperature on both material-level properties and global structural stiffness of a composite wind turbine blade. Material characterization was performed using tensile tests on specimens extracted directly from a 12.6 m research blade and tested at four temperature levels between +20 °C and −20 °C. Young’s modulus and Poisson’s ratio were identified to quantify temperature-dependent elastic behaviour. In parallel, static tests were conducted on the full blade inside a large-scale climate chamber under controlled thermal conditions. Quasi-static flap-wise loading was applied incrementally, while the response was measured using strain gauges, displacement sensors, load measurements, and internal temperature monitoring. The coupon-level results revealed substantial specimen-to-specimen scatter, which limited the statistical clarity of the identified temperature trends, although an overall increase in stiffness with decreasing temperature was observed. In contrast, the blade-level tests showed a clear, repeatable, and nearly linear increase in effective stiffness as temperature decreased. The mean structural stiffness change over the investigated temperature range was 2.7%, with good repeatability across measurement channels. Comparison of the two scales highlights that coupon-level trends cannot be directly translated into structural behaviour without accounting for blade architecture and load transfer mechanisms. The findings demonstrate that temperature-induced stiffness variations should be explicitly considered in the interpretation of monitoring data and in the development of reliable digital twins for wind turbines operating in cold climates.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120682"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148651587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Free vibration analysis of orthotropic L-shaped stepped plates based on the symplectic superposition method","authors":"Zhenzhen Tong,&nbsp;Jiacheng Han,&nbsp;Zhuoqi Yuan,&nbsp;Bingxin Liu,&nbsp;Wei Wang,&nbsp;Zhen Zhao","doi":"10.1016/j.compstruct.2026.120676","DOIUrl":"10.1016/j.compstruct.2026.120676","url":null,"abstract":"<div><div>Orthogonally anisotropic L-shaped stepped plate is a thin plate that exhibits different mechanical properties along orthogonal directions. This characteristic makes it widely applicable in the engineering field. Currently, the primary methods for solving the free vibration problem of such plates are numerical methods and the finite element method (FEM). However, in practical applications, analytical solutions can yield results with higher accuracy. Therefore, this paper focuses on orthogonally anisotropic L-shaped stepped plate and employs the symplectic superposition method to solve the free vibration problem of such plates. First, starting from the free vibration equations for thin plates, the orthogonally anisotropic thin plate is incorporated into the Hamilton system, and the original problem is decomposed into three subproblems. Then, the free vibration problem of the thin plate with boundary conditions is superimposed to obtain a basic solution set. Based on this, the three subproblems of the orthotropic L-shaped stepped plate are superimposed to determine the free vibration frequencies and modes. Next, the analytical solutions for frequencies and mode shapes are derived through ensuring the equivalence between the initial problem and the combination of sub-problems. Finally, the finite element method is used to validate and present a comprehensive analysis of the natural frequencies and mode shapes obtained from this method. This method possesses the benefits of rapid convergence and accurate precision, rendering it well suited for the analytic modeling of a broader range of plate-related problems.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120676"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148645855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability and vibration analysis of GOri metamaterial sandwich cylindrical panel supported by elastic foundation","authors":"E.Mohammad-Rezaei Bidgoli,&nbsp;O. Civalek","doi":"10.1016/j.compstruct.2026.120671","DOIUrl":"10.1016/j.compstruct.2026.120671","url":null,"abstract":"<div><div>In the current work, the aerodynamic behavior and free vibration characteristics of a circular cylindrical sandwich panel are investigated. The panel features a core reinforced with graphene origami (GOri) particles, while the face sheets are reinforced with carbon nanotube (CNT) inclusions. The structure lies on a Pasternak elastic foundation and is subjected to thermal loading as well as a three–dimensional electric field, with all material properties considered temperature–dependent. In addition, the face sheets exhibit piezoelectric properties. The panel is exposed to a supersonic airflow, representing the aerodynamic loading condition assumed in this study. To model the distribution of GOri particles through the core thickness, four distinct patterns are adopted. Likewise, three forms of CNT alignment throughout the face sheets’ thickness are utilized to accurately simulate the piezoelectric layers. Using the higher–order sinusoidal shear deformation theory (HSSDT) in conjunction with Hamilton’s principle, a unified formulation is developed to capture the coupled aerodynamic, thermal, and electromechanical behavior of the GOri–core/CNT–reinforced cylindrical sandwich panel. Under simply supported boundary conditions, the formulated equations are solved through the Galerkin method to examine both aeroelastic and free vibration behaviors of the structure. The accuracy of the results and the reliability of the developed code are verified by comparing them with previously published studies. The effects of several key parameters including ambient temperature, various distributions of GOri and CNT particles, geometric characteristics of the cylindrical panel, the folding degree of GOri–reinforced structures, and the applied electric voltage are thoroughly examined. The obtained results reveal that increasing temperature causes a simultaneous reduction in both the nondimensional critical aerodynamic pressure and the nondimensional natural frequencies. For the considered temperature variations of ΔT = 0, 50, and 80  K, the corresponding nondimensional critical aerodynamic pressures are 4.34, 3.98, and 3.45, respectively. The results provide new insights into how nano–reinforcement architecture and thermal environments interact to influence aeroelastic stability boundaries and vibration characteristics of multifunctional sandwich structures, which is particularly relevant for next–generation aerospace panels operating under coupled thermo–aerodynamic conditions.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120671"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148645858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlocal strain gradient analysis of electro-magneto-thermoelastic curved functionally graded nanobeams- free vibrational study by sinus beam model accounting for normal deformation","authors":"N. Spoorthi,&nbsp;O. Polit,&nbsp;M. D’Ottavio,&nbsp;S. Kavya,&nbsp;G. Manickam","doi":"10.1016/j.compstruct.2026.120691","DOIUrl":"10.1016/j.compstruct.2026.120691","url":null,"abstract":"<div><div>The present work focuses on the size-dependent effects on the free vibration behavior of Electro-Magnetic-Thermo-Elastic (EMTE) Functionally Graded (FG) curved nanobeams. This study is conducted using a nonlocal strain-gradient theory and a sinusoidal shear beam theory, including the transverse normal deformation effect. The beam with functionally graded materials, comprising metal and ceramic, is considered to obtain variation in elastic, thermal, electrical, and magnetic properties. The initial strain due to the temperature rise across the beam thickness, evaluated from the heat-conduction formulation, is included. The equilibrium equations derived using Hamilton’s principle are solved for the simply supported beam case, employing Navier’s approach. The natural frequencies obtained from this model are first compared with the available results of the EMTE-FG flat beam. A systematic parametric investigation is made on the dynamic characteristics of the curved EMTE-FG nanobeam by varying nonlocal stress and material length-scale parameters, and considering other physical variables such as beam included angle, the slenderness ratio, material power-law index, and the electrical/magnetic field potential.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120691"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148645860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Explicit design equation for flange local buckling of pultruded FRP beams and columns with I- and box-sections","authors":"TianQiao Liu,&nbsp;Tianye Li,&nbsp;Kent A. Harries,&nbsp;Daniel Cardoso,&nbsp;Weichen Xue,&nbsp;Xiuli Du","doi":"10.1016/j.compstruct.2026.120700","DOIUrl":"10.1016/j.compstruct.2026.120700","url":null,"abstract":"<div><div>Flange local buckling (FLB) is a critical limit state for pultruded FRP (PFRP) beams and columns due to material orthotropy, low elastic moduli, and brittle failure characteristics. Existing mechanics-based models achieve accuracy at the cost of complexity, requiring iterative solutions or rotational restraint coefficients that are difficult to reliably characterize. Design standards – often using inconsistent formulations across member types – are shown to provide predicted capacities that are often excessively conservative or provide inconsistent reliability in design. This study addresses this gap by presenting a simple, unified, explicit design equation for FLB strength of PFRP beams and columns with I- and box-sections. The proposed equation adopts a form analogous to conventional plate buckling solutions, with a single empirical coefficient<!--> <!-->calibrated separately for I-beams, I-columns, box-beams, and box-columns against an extensive experimental database comprising 119 tests reported in the literature. Calibration targets a mean <em>experimental-to-predicted</em> ratio of 1.00 for each member type. The unified algebraic form of proposed equation requires only basic geometric dimensions (<em>b</em> and <em>t_f</em>) and readily obtained material properties (<em>E_L</em>, <em>E_T</em>, and <em>v_LT</em>). The proposed equation offers a balance between accuracy and simplicity, providing a robust tool for routine engineering design of PFRP structures.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120700"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148645864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-material dynamic topology optimization for customized wide-bandwidth flexoelectric composite structures","authors":"Xing Chen,&nbsp;Julien Yvonnet,&nbsp;Song Yao","doi":"10.1016/j.compstruct.2026.120690","DOIUrl":"10.1016/j.compstruct.2026.120690","url":null,"abstract":"<div><div>To fully exploit the distinct performance advantages of multiple materials and further enhance the customized wide-bandwidth electromechanical coupling factor (ECF) of flexoelectric composite structures, we propose a novel multi-material dynamic topology optimization framework for flexoelectric energy harvesting. The governing fourth-order partial differential equations of flexoelectricity are solved by isogeometric analysis, while the multi-material properties are interpolated through the Discrete Material Optimization scheme. A wide-bandwidth max–min formulation is developed by discretizing the prescribed frequency range into multiple frequency points and aggregating the corresponding ECF responses via the KS function, which provides a smooth approximation of the minimum ECF over the target band. Static compliance constraint is further incorporated to ensure sufficient structural stiffness, suppress disconnected layouts, and, to some extent, stabilize the convergence process induced by the highly nonlinear KS function for the ECFs. Numerical investigations on both single-frequency and wide-bandwidth cases demonstrate that the proposed framework is effective and adaptable for different structural types, material combinations, and frequency-band design strategies. Furthermore, the single mass constraint is shown to be more effective than the multiple volume constraints in identifying favorable material layouts. The proposed framework is capable of achieving both narrow-band high-performance and wide-band stable electromechanical conversion, and thus provides a promising design methodology for flexoelectric composite energy harvesters.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120690"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148645866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The switching behavior and tunability of piezoresistance in fluid-filled bi-material composite cylinders","authors":"Ettore Barbieri,&nbsp;Taiyo Kobayashi","doi":"10.1016/j.compstruct.2026.120680","DOIUrl":"10.1016/j.compstruct.2026.120680","url":null,"abstract":"<div><div>Hydrostatic pressure typically increases the electrical resistance of fluid-filled cylinders due to geometric contraction, posing calibration challenges for precision sensors. We demonstrate that this electromechanical response can be tuned or reversed in bi-material composite cylinders by engineering their geometric, material, and interfacial stiffness properties. Using sequential multiphysics finite-element simulations and a closed-form analytical model, we map the design space for various composite configurations. Our results reveal a critical switching behavior in which the piezoresistance pressure coefficient transitions from positive to negative, governed by the interplay among layer stiffness contrast, thickness ratio and interfacial shear compliance. Ultimately, we identify the specific conditions required to achieve a ‘zero-sensitivity’ state, rendering the structure electromagnetically invariant to pressure.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120680"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148645867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physics-guided machine learning for the failure prediction of a novel Z-beam composite wing structural concept","authors":"Runze Li,&nbsp;Mário Miranda,&nbsp;Lucian Iorga,&nbsp;Silvestre T. Pinho","doi":"10.1016/j.compstruct.2026.120662","DOIUrl":"10.1016/j.compstruct.2026.120662","url":null,"abstract":"<div><div>To enhance the structural and aerodynamic performance of next-generation civil aircraft, novel composite wing concepts are being explored for aeroelastic tailoring and weight reduction. However, conventional analytical and empirical tools struggle to evaluate these complex configurations at early design stages, limiting the exploration of their full potential. This study develops physics-guided machine learning models for the prediction of mechanical response and failure behaviour of innovative Z-beam-based composite wing structures. The Z-beam concept provides increased geometric freedom, enabling tailored bending–torsion coupling. A dataset of representative Z-beam elements is generated using finite element simulations with periodic boundary conditions. Local stress concentrations are analysed using refined sub-models with LaRC05 failure criteria to compute detailed failure indices. A physics-guided learning framework is proposed to predict failure indices, dominant failure modes, and critical locations within the wing box. The framework embeds the linearity of elastic response and the monotonic relation between strain and failure indices to enhance data efficiency and prediction robustness. A second model is trained to estimate bending, torsional, and coupling stiffness properties. Results show that the proposed models deliver high predictive accuracy, providing an effective tool for early-stage design exploration and optimisation of composite wing structures.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120662"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148651589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Single-sensor impact force reconstruction in composite structures via a physics-guided multi-source data fusion network","authors":"Mingxuan Huang,&nbsp;Chunxing Hu,&nbsp;Zhonghai Xu,&nbsp;Chaocan Cai,&nbsp;Weilong Yin,&nbsp;Qingyu Peng","doi":"10.1016/j.compstruct.2026.120706","DOIUrl":"10.1016/j.compstruct.2026.120706","url":null,"abstract":"<div><div>With the continuous advancement of structural health monitoring (SHM) systems for composite structures, accurately reconstructing time-varying impact forces from complex, noise-contaminated acceleration signals presents a critical computational challenge. To address the inherent limitations of conventional multi-impact inversion methods while maintaining real-time performance, we propose the Force Reconstruction with Transmissibility Enhanced Network (FRTE-Net). By integrating multimodal time–frequency domain physical information with attention mechanisms, FRTE-Net effectively aligns its computational workflow with the generalized transmissibility computational process. Experimental validation conducted on a composite flat plate and a foam-core blade using a single sensor demonstrates FRTE-Net’s substantial performance advantages. Specifically, the proposed method achieves a peak force prediction accuracy exceeding 88.91 %, outperforming CNN, DCNN, and DCSCNet by 19.96 %, 4.84 %, and 12.80 %, respectively, with peak position errors ranging from 0.61 to 29.81 ms. Given the richer input information used by FRTE-Net, these improvements should be interpreted as the overall benefit of the proposed multi-source physics-guided framework. The average Pearson’s correlation coefficients of 0.9059 and 0.8847 for the two test structures further affirm FRTE-Net’s efficacy in capturing the temporal profiles of repeated impacts at identical locations with high fidelity. Finally, comprehensive evaluation across varied sensor placements and artificially induced damage stages reveals the structural center as the optimal sensor location, maintaining peak accuracy above 88.48 % even under severe damage conditions. Collectively, these findings indicate that FRTE-Net provides a practical and computationally efficient approach for single-sensor impact force reconstruction in the tested composite structures.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120706"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148651591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topology optimization of isotropic viscoelastic microstructures based on periodic homogenization","authors":"Hiroaki Deguchi,&nbsp;Kei Matsushima,&nbsp;Takayuki Yamada","doi":"10.1016/j.compstruct.2026.120670","DOIUrl":"10.1016/j.compstruct.2026.120670","url":null,"abstract":"<div><div>Mitigating low-frequency noise is particularly challenging due to its limited natural attenuation. This study aims to design viscoelastic composite microstructures that achieve both low acoustic reflection and high internal damping by simultaneously enhancing their effective acoustic impedance and attenuation characteristics. Using complex-valued periodic homogenization theory and density-based topology optimization, viscoelastic and impedance-matching materials are designed within a highly symmetric unit cell to manipulate these isotropic properties. Numerical results show that the optimized isotropic design robustly outperforms its constituent materials and simple anisotropic laminate structures, exhibiting performance that is stable across a wide frequency band, independent of orientation, and stable across various structural scales. This demonstrates the potential of microstructural engineering for effective low-frequency noise mitigation.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"394 ","pages":"Article 120670"},"PeriodicalIF":7.8,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148645851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}