Zhongliang Cao , Yang Zhang , Xianfeng Wang , Chen Liu
{"title":"Optimisation of large-Scale composite blade layup using coupled finite element method and machine learning","authors":"Zhongliang Cao , Yang Zhang , Xianfeng Wang , Chen Liu","doi":"10.1016/j.compstruct.2025.119150","DOIUrl":"10.1016/j.compstruct.2025.119150","url":null,"abstract":"<div><div>This study focuses on the layup design of composite blades to enhance the mechanical properties of blades by adjusting the layup angle. The objective is to apply a generalised regression neural network (GRNN) to construct a surrogate model for multi-objective optimisation of composite blades. Four objectives are considered: the maximum displacement of the blade tip (to be minimised) and three metrics measuring the difference between the intrinsic frequency and the excitation frequency, called ‘resonance margin’ (to be maximised). Most of the lay-up angles of the composite blade are fixed and only two directions are considered as variables. Subsequently, the study incorporates the Non-dominated Sequential Genetic Algorithm II (NSGA-II) for multi-objective optimisation. The optimisation scheme achieves a dual enhancement of blade stiffness and resonance margin. After optimisation, the maximum displacement of the blade tip is reduced by about 32% compared with the pre-optimisation. The first three resonance margins are improved, especially the second order resonance margin is increased from 8.15% to 35.18%. The R<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> value of the GRNN model of the blade is greater than 0.95. The high-precision surrogate model achieves accurate prediction of the mechanical properties of the blade. The trade-off of various properties of composite blades was achieved by NSGA-II algorithm.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"364 ","pages":"Article 119150"},"PeriodicalIF":6.3,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783625","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":"Equilibrium-based 3D stress recovery of laminated anisotropic composite plates via isogeometric analysis","authors":"Sajad Jangravi , Pedram Khaneh Masjedi , Alessandro Reali","doi":"10.1016/j.compstruct.2025.119144","DOIUrl":"10.1016/j.compstruct.2025.119144","url":null,"abstract":"<div><div>Composite materials have wide-ranging applications in various engineering fields due to their unique mechanical properties and superior performance. However, the out-of-plane, through-the-thickness stresses may result in delamination failure, and most existing composite plate models are typically unable to capture them with a good accuracy-to-cost ratio. In this paper, we propose a stress recovery method based on Isogeometric Analysis (IGA) to overcome this challenge. The proposed method involves two steps: first, a displacement solution is obtained by applying the classical composite plate theory based on a Galerkin isogeometric formulation. This is followed by the computation of the in-plane stress derivatives required to accurately recover the out-of-plane stresses, directly enforcing strong-form equilibrium across the plate thickness. The governing equations employ Kirchhoff plate theory, while the equilibrium equations and numerical integration, using the composite trapezoidal rule, discretize the plate thickness into layers to extend stress recovery to three dimensions. This method requires high-order continuity; therefore, isogeometric analysis, known for its high accuracy and continuity properties, becomes a desirable option. Our efficient method shows remarkable accuracy, matching Pagano’s solution for cross-ply laminates and 3D FEM for angle-ply, symmetric, and unsymmetric across various test scenarios.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"365 ","pages":"Article 119144"},"PeriodicalIF":6.3,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834417","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}
M. Nasseer A. Mohammed , Riccardo Augello , Munise Didem Demirbas , Erasmo Carrera
{"title":"Delamination analysis of Functionally Graded Materials using Carrera Unified Formulation and Cohesive Zone Model","authors":"M. Nasseer A. Mohammed , Riccardo Augello , Munise Didem Demirbas , Erasmo Carrera","doi":"10.1016/j.compstruct.2025.119147","DOIUrl":"10.1016/j.compstruct.2025.119147","url":null,"abstract":"<div><div>This paper investigates the delamination behavior of Functionally Graded Materials (FGMs) using Carrera Unified Formulation (CUF) and Cohesive Zone Model (CZM). Characterized by spatially varying material properties, FGMs are increasingly used in advanced engineering applications but are prone to delamination. The numerical model is developed by using a combination of CUF and CZM. In this study, a cantilever FGM beam was subjected to opposing forces from its free end and analyzed for delamination. Here, the delamination process is correctly addressed, and using the fracture mechanics of CZM, the crack initiation, propagation, and branching along the cohesive elements governed by the tension-separation law were also calculated. Finally, different compositional gradient exponents are accounted.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"365 ","pages":"Article 119147"},"PeriodicalIF":6.3,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143821468","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":"A regional integral iFEM for deformation sensing of the large-scale composite panel under complex service conditions","authors":"Jian Chen, Wenpeng Duan, Shenfang Yuan, Ao Zhang","doi":"10.1016/j.compstruct.2025.119149","DOIUrl":"10.1016/j.compstruct.2025.119149","url":null,"abstract":"<div><div>Accurate and robust deformation sensing is of great significance for large-scale composite panels that are widely used in aerospace. The inverse finite element method (iFEM) has been deemed as one of the promising techniques due to its full-field reconstruction capability. However, engineering large-scale composite panels usually suffer from complex service conditions such as non-uniform distributed loads and internal displacement constraints. Under such conditions, strain in inverse elements may distribute irregularly so that measured strain at the element’s center can no longer reflect the strain distribution over the entire element, leading to a reduction of deformation sensing accuracy. This paper proposes a regional integral iFEM to improve the deformation sensing accuracy under complex service conditions. The method incorporates a service dimension constrains-based element partition strategy to generate inverse elements so that strain in the local element region is as uniform as possible. Besides, a regional integral error function (RIEF) is developed for deformation reconstruction, using strain over the element for deformation sensing instead of the strain at the element’s center. This method is validated through simulation and experiment of a large-scale multilayer-heterogeneity composite panel, and the maximum error decreased by 44% for all laboratory test cases.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"365 ","pages":"Article 119149"},"PeriodicalIF":6.3,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143826058","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}
Jaeho Yun , Seungjun Ryu , Jinsol Kim , Yongha Kim , Do-Won Kim
{"title":"Equivalent modeling for the prediction of mechanical behaviors of composite sandwich structures with thick cell walls","authors":"Jaeho Yun , Seungjun Ryu , Jinsol Kim , Yongha Kim , Do-Won Kim","doi":"10.1016/j.compstruct.2025.119162","DOIUrl":"10.1016/j.compstruct.2025.119162","url":null,"abstract":"<div><div>An equivalent model is proposed for the prediction of the mechanical behaviors of a honeycomb core with thick cell walls, including the calculation of failure strength. The method was derived from the homogeneous method used to investigate the mechanical behaviors of composite sandwich structures. We validated the method’s utility through the finite element method and experimentally. A parametric analysis was performed to examine the mechanical properties of a composite sandwich structure with thick cell walls using the proposed method. These results were used to compile information about the mechanical characteristics of the structure for aerospace applications. In conclusion, the method is demonstrated to be well suited for its intended applications due to its relative simplicity and computational efficiency.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"364 ","pages":"Article 119162"},"PeriodicalIF":6.3,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792320","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":"Hybrid neural network for the prediction of damage patterns in open-hole composites","authors":"Karthik Venkatesan, Boyang Chen","doi":"10.1016/j.compstruct.2025.119121","DOIUrl":"10.1016/j.compstruct.2025.119121","url":null,"abstract":"<div><div>Damage pattern predictions of open-hole laminates under different loading conditions are ubiquitous in the finite element modelling of composite structures. This work investigated the applicability of artificial neural networks for the fast and accurate generation of damage patterns for a composite plate with a cut-out under a variety of loading conditions. The purpose is to explore the neural networks as surrogate models capable of returning damage pattern predictions on par with a finite element model, but requiring less computational effort at run time. Data for training and evaluating these neural networks was generated through nonlinear finite element models. Different neural networks, such as a standard Feedforward Neural Network and a Hybrid Neural Network that combines a Feedforward Neural Network with a convolutional decoder, have been tested for this task. To quantify the resemblance between the predicted and actual outputs in terms of colours and contours, different performance metrics have been explored. The use of the Structural Similarity Index (SSIM), in addition to the standard Mean Square Error (MSE), was explored to improve the visual quality of outputs from the neural network. With an average test MSE of 0.0014, SSIM of 0.9814, and computational speedup factor of 34, the Hybrid Neural Network has been shown to accurately and efficiently predict the damage patterns of the open-hole laminate, thereby constituting a promising candidate for a surrogate model of open-hole composite panels.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"364 ","pages":"Article 119121"},"PeriodicalIF":6.3,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783626","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":"An explicit finite element discrete crack analysis of open hole compression failure in composites","authors":"K. Tian , J. Zhi , V.B.C. Tan , T.E. Tay","doi":"10.1016/j.compstruct.2025.119167","DOIUrl":"10.1016/j.compstruct.2025.119167","url":null,"abstract":"<div><div>This paper presents a comparative study of implicit and explicit finite element methods in simulating open hole compression (OHC) failure in composite laminates, employing the Discrete Crack Method (DCM) with the Floating Node Method (FNM) for enhanced accuracy in matrix crack modeling. The finite element models are built upon experimental OHC tests of carbon fiber/epoxy laminates with both ply-level and sub-laminate scaling. The models are validated through a series of simulations studying the effects of hole sizes on ultimate strength and damage modes. The FNM allows for accurate tracking of crack initiation and propagation. Additionally, parametric analysis further evaluates the impact of factors such as damping, mass scaling, and matrix cracks spacing on the simulation outcomes. The explicit method shows significant savings in computational times. The study demonstrates the effectiveness of the FNM within the explicit FEM framework for predicting OHC failure in composite laminates with precision and efficiency.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"364 ","pages":"Article 119167"},"PeriodicalIF":6.3,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792319","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}
Heraldo S. Da Costa Mattos, João Laredo dos Reis, Bernardo Santiago Areias, Sérgio Luiz de Souza Junior, Maria Laura Martins-Costa
{"title":"Influence of the application time on the failure pressure of bonded metal/composite layers in presurized blister tests","authors":"Heraldo S. Da Costa Mattos, João Laredo dos Reis, Bernardo Santiago Areias, Sérgio Luiz de Souza Junior, Maria Laura Martins-Costa","doi":"10.1016/j.compstruct.2025.119161","DOIUrl":"10.1016/j.compstruct.2025.119161","url":null,"abstract":"<div><div>An alternative method to repair through-wall corrosion defects in pipelines is to use a composite sleeve over the damaged region. Between the metallic surface and the composite surface, it is usually applied an adhesive primer layer. The adhesive is a mixture of a resin (which may not be the same used in the composite) and a curing agent. The bonding efficiency can be significantly impacted by the time it takes to join the adherends with the adhesive after mixing the resin with the hardener. This study investigates the influence of this time interval to join a particular class of composite and metal adherends (which will be called the <em>Initial Time for Application t<sub>i</sub></em>) on the failure pressures obtained in hydrostatic blister tests. Blister tests were carried out to verify the failure pressure considering different time intervals <em>t<sub>i</sub></em>. It is observed that the failure pressure may increase significantly after a given time interval. An analytical model is proposed to predict the failure pressure as a function of <em>t<sub>i</sub></em>. Finally, it is suggested how to adapt these experimental observations to the testing and design of real corroded pipeline repairs with composites using concepts from Linear Elastic Fracture Mechanics.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"364 ","pages":"Article 119161"},"PeriodicalIF":6.3,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143785324","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":"Compressive behaviour and mechanisms of supersulfated cement enhanced by biochar","authors":"Ziye Kang , Ning Li , Yilun Yang , Tianchang Li","doi":"10.1016/j.compstruct.2025.119127","DOIUrl":"10.1016/j.compstruct.2025.119127","url":null,"abstract":"<div><div>The incorporation of biochar (BC) into supersulfated cement (SSC) offers a promising approach to enhance its low-carbon performance. This study explores the compressive behavior and mechanisms of BC-modified SSC through compressive strength, acoustic emission, digital image correlation, and scanning electron microscopy tests. The results reveal that 2 % BC optimally increases compressive strength by 11.0 %, and a strength prediction model is proposed. Apparent crack analysis demonstrates that BC-modified SSC exhibits diverse cracking patterns. The transverse strain of SSC containing 2 % BC is 1.2 times greater than unmodified SSC. Microcrack monitoring indicates that the AE signal amplitude of SSC modified with 2 % BC extends beyond the original range of 35–60 dB observed in pure SSC paste, reaching 60–80 dB due to the fracture of BC. Furthermore, the inclusion of 2 % BC increases the proportion of shear cracks in SSC composites to 44.1 %, primarily attributed to the dislocation effect induced by BC interlocking. Microstructure observations show that BC tends to induce cracking in interfacial transition zone. At the optimal dosage, BC densifies the matrix and significantly enhances energy dissipation through longitudinal splitting and transverse fracture. Thus, the appropriate incorporation of BC can markedly improve the compressive cracking resistance of SSC composites.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"365 ","pages":"Article 119127"},"PeriodicalIF":6.3,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816256","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}
Yi Zhang , Wei Zhong Jiang , Xiang Yu Zhang , Jun Wen Shi , Yi Chao Qu , Jun Dong , Xin Ren
{"title":"Re-entrant thermal-responsive metamaterials with widely tunable thermal expansion","authors":"Yi Zhang , Wei Zhong Jiang , Xiang Yu Zhang , Jun Wen Shi , Yi Chao Qu , Jun Dong , Xin Ren","doi":"10.1016/j.compstruct.2025.119166","DOIUrl":"10.1016/j.compstruct.2025.119166","url":null,"abstract":"<div><div>Auxetic metamaterials have been widely used in sensing, flexible medical devices, and energy absorption, due to their extraordinary physical properties. However, the active tunability of their deformation shapes and mechanical performances remains a significant challenge, which limits the functional applications. Here, we fabricate several auxetic re-entrant honeycombs integrated with thermostat metal strips to achieve arbitrary thermal shape morphing at a wide temperature range. The findings indicate that the maximum positive and negative thermal strains achieved are 45 % and 37 %, respectively. In addition, we introduce a customizable thermal deformation strategy by tessellating the unit cells with different thermo-responsive characteristics, including isotropic or anisotropic thermal expansions. An Ashby plot of thermal strain vs. temperature span among current thermo-responsive metamaterials is concluded to quantitatively compare the capacities that actively tune their thermal morphing configurations. The uniaxial thermal strain range in finite elements is substantially expanded to –47 % to 94 % at a wide working temperature range. Various potential functionalities and applications are illustrated including the tunable bandgap for vibration isolation, multisignal conversion in sensing devices, and thermal actuators.</div></div>","PeriodicalId":281,"journal":{"name":"Composite Structures","volume":"364 ","pages":"Article 119166"},"PeriodicalIF":6.3,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777593","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}