Article
Mechanics
Xiaodong Chen, Guojun Nie
Summary: This article investigates the nonlinear thermal flutter characteristics of an infinitely long VAT composite curved panel in supersonic airflow, utilizing qualitative tools to study the dynamic behaviors and validating the proposed Galerkin procedure. Effects of various parameters on the nonlinear flutter responses of VAT composite curved panels in thermal environments are also discussed.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Civil
Tanish Dey, Eelco Jansen, Rajesh Kumar, Raimund Rolfes
Summary: This article explores the instability characteristics of variable stiffness laminated composite shell panels subjected to non-uniform periodic excitations. The results show that the fiber angle orientations, non-uniform distribution of in-plane loadings, and damping have a significant influence on the dynamic instability of VSLC shell panels.
THIN-WALLED STRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
Alireza Amiri Esfarjani, Mohammad Bagher Nazari, Seyed Hadi Bayat
Summary: In this paper, a study on the dynamic fracture assessment of Variable Angle Tow (VAT) composite laminates is presented. An interaction integral is developed to extract the mixed-mode Stress Intensity Factors (SIFs) for a dynamically propagating crack, and comprehensive tip enrichment functions are implemented in the framework of XFEM. Results show that the crack follows the fiber path in quasi-stationary loading, but may change in dynamic loading conditions.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Mechanics
Kunpeng Zhang, Dachuan Liu, Qun Wang, Peng Hao, Yuhui Duan, Hao Tang, Bo Wang
Summary: This study proposes an image-driven intelligent optimization method for the design of fiber variable angle-tow (VAT) laminates. By accurately describing the VAT fiber angle vector field and mapping it into gray images, as well as training convolutional neural networks (CNNs) for deep learning models, the design of VAT laminates is effectively optimized.
COMPOSITE STRUCTURES
(2023)
Article
Computer Science, Interdisciplinary Applications
S. Valvano, A. Alaimo, C. Orlando
Summary: In this paper, the damped free-vibration and frequency response analysis of variable-angle-tow composite plates embedding viscoelastic layers with frequency-dependent properties are performed. The governing equations are derived and a nine-node finite plate element is employed for solving. The plate formulation presented in this paper is more efficient and accurate than existing methods thanks to the use of the mixed interpolation of tensorial components technique. Different multilayered structures laminated with unidirectional cross-ply layers or curvilinear fibers path ones are considered. Numerical solutions are presented for variable-angle-tow composites with different boundary conditions and lamination schemes.
COMPUTERS & STRUCTURES
(2023)
Article
Computer Science, Interdisciplinary Applications
Zhao Jing, Siqi Wang, Lei Duan, Biao Li, Xueling Fan
Summary: A novel variable stiffness optimization algorithm is proposed for variable angle tow (VAT) plates. By sampling in the design space of lamination parameters, a good initial point is identified for the stacking sequence design. The stiffness of VAT plates is enhanced through point-by-point optimization of fiber paths. Ritz-type buckling solutions are presented for VAT composite plates, and the buckling resistance capacity of optimized VAT plates can be improved approximately twice over constant-stiffness laminates.
COMPUTERS & STRUCTURES
(2023)
Article
Engineering, Multidisciplinary
Francesco Tornabene, Matteo Viscoti, Rossana Dimitri
Summary: This study investigates the dynamic behavior of laminated anisotropic doubly-curved shells with a generalized distribution of the material orientation angle using higher order theories. The equivalent single layer methodology is used to develop the structural problem and establish a unified approach for evaluating displacement field variables with higher order theories. A generalized three-dimensional distribution of the material orientation angle is associated with each layer of the stacking sequence, accounting for in-plane bivariate power distribution and out-of-plane symmetric and unsymmetric profiles described with polynomial and non-polynomial analytical expressions. The fundamental equations are derived using the Hamiltonian Principle and numerically solved using the Generalized Differential Quadrature method.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2023)
Article
Computer Science, Interdisciplinary Applications
Bjorn Andersson, Shaobo Jin, Maoxin Zhang
Summary: A computationally efficient method for marginal maximum likelihood estimation of multiple group generalized linear latent variable models for categorical data is introduced. The method utilizes second-order Laplace approximations and considers symmetries to improve computational efficiency. Simulation and empirical examples show that it performs similarly to adaptive Gauss-Hermite quadrature while being more efficient.
COMPUTATIONAL STATISTICS & DATA ANALYSIS
(2023)
Article
Engineering, Aerospace
Minghui Yi, Fei Liu, Wuxiang Zhang, Xilun Ding
Summary: Variable angle tow steering technology improves the forming efficiency and mechanical properties of composite structures by manufacturing complex aviation parts with intricate curvature. Theoretical and simulation models are used to optimize process parameters and effectively suppress forming defects.
Article
Mechanics
Zexi Wang, Zhiqiang Wan, Rainer M. J. Groh, Xiaozhe Wang
Summary: By utilizing a global-local approach, the study optimized a full-scale wing-box structure using VAT fibre and CTS designs under realistic aeroelastic loading conditions, achieving mass reduction and structural performance optimization.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Civil
H. Li, Y. X. Hao, W. Zhang, S. W. Yang, Y. T. Cao
Summary: This paper investigates the natural vibration characteristics of a porous metal cylindrical curved panel with spring supported boundary conditions. The cylindrical curved panel is made of porous metal and three types of porosity distribution in the thickness direction are considered. The theoretical formulations for the free vibration of the cylindrical curved panel are established using the first-order shear deformation theory (FSDT) and Hamilton's principle, and a novel dynamics system for the porous cylindrical curved panel in physical space is presented. The governing equations of natural vibration and boundary conditions are discretized using the differential quadrature method (DQM), resulting in an algebraic representation. The study also examines the influence of geometric dimensions, spring stiffness, porosity, and distribution types on the natural vibration of the cylindrical curved panel.
THIN-WALLED STRUCTURES
(2023)
Article
Engineering, Aerospace
Nasim Fallahi
Summary: In this research, variable angle tow composites were utilized to enhance the buckling and vibration behavior of structures. The approach involved employing a 1D CUF and GA optimization method, with the effectiveness of the GA approach confirmed through the use of the RS method. The results demonstrated a cost reduction in optimized VAT performance through GA optimization, and the applicability of LHS sampling for future research stages was also confirmed.
Article
Engineering, Mechanical
Kun Nie, Yi Liu
Summary: This paper presents three-dimensional solutions for the buckling of variable angle tow composite laminated plates using the 3Dp-FEM method. The accuracy of the method is confirmed by comparing the numerical results with those in the literature, indicating that these 3D results may serve as a benchmark for future studies.
INTERNATIONAL JOURNAL OF MECHANICS AND MATERIALS IN DESIGN
(2021)
Article
Mathematics, Applied
Luisa Fermo, Maria Grazia Russo, Giada Serafini
Summary: This paper considers the generalized Love integral equation and proposes a Nystrom method based on a mixed quadrature rule for its approximation. The stability and convergence of the numerical procedure are discussed in suitable weighted spaces, with the efficiency of the method shown through numerical tests.
NUMERICAL ALGORITHMS
(2021)
Article
Materials Science, Multidisciplinary
Zhongliang Cao, Guojun Lin, Qinghe Shi, Qinglin Cao
Summary: This study focuses on the optimization design of variable stiffness laminates with a hole based on cubic NURBS curve. By utilizing variable angle fiber placement and radial basis function, an optimization model is established and the optimal results are obtained through comparative analysis.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Mechanics
R. Manikantan, T. Ghosh Mondal, S. Suriya Prakash, C. P. Vyasarayani
Summary: This article introduces the use of the homotopy technique to identify unknown parameters in the hysteresis model of structural members. Through a comparison with global optimization methods, the superiority of the homotopy method in terms of computational effort and convergence efficiency is confirmed.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2022)
Article
Engineering, Civil
M. M. S. Vilar, P. Khaneh Masjed, D. A. Hadjiloizi, Paul M. Weaver
Summary: An efficient analytical plane-stress recovery methodology is introduced in this study to accurately predict the stress field in non-prismatic beams under surface forces and non-uniform loads applied to a part of the cross-sectional area. The results show that the developed formulation has high accuracy and the error increases with the taper angle.
ENGINEERING STRUCTURES
(2022)
Article
Engineering, Aerospace
Shahrzad Daghighi, Giovanni Zucco, Paul M. Weaver
Summary: Pressure vessels are widely used in various industries, including hydrogen storage and aircraft fuselages. Designing pressure vessels involves considering factors such as failure performance, weight, and packing efficiency. This study develops an initial design methodology for bend-free super ellipsoids of revolution to withstand both uniform internal pressure and thermal loads.
Article
Mechanics
Daniel Peeters, David Jones, Ronan O'Higgins, Paul M. Weaver
Summary: Interest in thermoplastic composites in aircraft has been increasing over the past 25 years. Combining winding and laser-assisted tape placement is a promising method to manufacture thermoplastic structures. In this study, a variable stiffness, unitized, integrated-stiffener thermoplastic wingbox was manufactured and tested. The corner regions were found to be critical and testing showed that decreasing the radius increases the corner strength, with an optimum radius existing to withstand maximum unfolding force/moment. The slowest deposition rate with least acceleration during manufacturing resulted in the highest corner strength for the same radius.
COMPOSITE STRUCTURES
(2022)
Article
Mechanics
Sumit Mehta, Gangadharan Raju, S. Kumar, Prashant Saxena
Summary: This paper studies the large deformation and subsequent instability of a thick-walled and compressible hyperelastic cylinder under internal pressure and external constraints. Perturbation theory is used to derive the partial differential equations that govern the bifurcation behaviour, and numerical solutions are obtained to evaluate the critical pressure. The results show that the critical pressure is affected by the wall-thickness and compressibility of the material, and for isotropic materials, the axial direction has lower critical pressure.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2022)
Article
Materials Science, Multidisciplinary
Ciarn McHale, Paul M. Weaver
Summary: This study aims to develop a method to increase the bending stiffness of lattice structures while minimizing the increase in mass and stowed volume. This is achieved by using additional composite strips mounted adjacent and concentric to pre-existing strips. The new lattice configuration has a lighter weight and smaller stowed height compared to conventional configurations, but may have reduced stiffness. By increasing the deployed bending stiffness, this work enhances the feasibility of the morphing cylindrical lattice for deployable space structures.
MATERIALS & DESIGN
(2022)
Article
Chemistry, Applied
Angeliki Chanteli, Marcus O. Conaire, Ruairi Brannigan, Andreas Heise, Paul M. Weaver, Ioannis Manolakis
Summary: This work demonstrates the use of azomethine-bearing diamines as hardeners for epoxy compounds, resulting in cleavable and thermoformable covalent adaptable networks that have comparable properties to conventional epoxy networks.
REACTIVE & FUNCTIONAL POLYMERS
(2022)
Article
Engineering, Aerospace
Reece L. Lincoln, Paul M. Weaver, Alberto Pirrera, Rainer M. J. Groh, Evangelos Zympeloudis
Summary: Variable-angle tow (VAT) manufacturing methods, such as rapid tow shearing (RTS), greatly enhance the design possibilities for composite structures by smoothly changing fiber angle and ply thickness. RTS offers numerous advantages over conventional bending-driven steering processes, including improved tessellation, elimination of overlaps or gaps between tows, and prevention of fiber wrinkling or bridging. This study aims to validate previous predictions on the imperfection sensitivity reduction and increased load-carrying capacity of cylindrical shells through the manufacturing and testing of RTS cylinders. The experimental results are compared with high-fidelity finite element models, taking into consideration the geometric and loading imperfections.
Article
Mechanics
Aileen G. Bowen, Giovanni Zucco, Paul M. Weaver
Summary: The design of composite flexible hinges using Brazier phenomena can avoid added weight and complexity. This study aims to verify similarities between Brazier phenomena for circular and aerofoil cross-sections through finite element analyses.
COMPOSITE STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Venkatesh Sundararaman, Matthew P. O'Donnell, Isaac Chenchiah, Gearoid Clancy, Paul M. Weaver
Summary: Structures with adaptive stiffness characteristics can achieve greater efficiency by reconfiguring their topology. In this study, the potential of using changes in the topology of planar lattice structures is explored to achieve desired adaptivity. The lattice structures can undergo elastic buckling or bending of cell walls, leading to a change in the structure's topology and enhancement of compressive and shear stiffness. Experimental observations correlate well with finite element analysis and analytical stiffness predictions. This topology morphing lattice structure offers a new route to tailor elastic characteristics.
MATERIALS & DESIGN
(2023)
Article
Materials Science, Multidisciplinary
A. L. Kalamkarov, D. A. Hadjiloizi, P. M. Weaver, A. Georgiades
Summary: A micromechanical model has been developed for the analysis of structurally periodic flexoelectric plates with periodically varying thickness based on asymptotic homogenization, which can be applied to a variety of thin plate structures.
MATHEMATICS AND MECHANICS OF SOLIDS
(2022)
Review
Materials Science, Characterization & Testing
Sasidhar Potukuchi, Viswanath Chinthapenta, Gangadharan Raju
Summary: The rapid advancements in biosensors, soft robotics, and tissue engineering have increased the demand for hydrogels and their composites. However, evaluating the physical, chemical, mechanical, and thermal properties of gels using traditional mechanical tests is difficult due to their low stiffness and slippery nature. Therefore, non-destructive evaluation (NDE) methods have become important. This article reviews various NDE techniques for mechanical evaluation of gels, discussing their advantages, disadvantages, and applications. The article also highlights future directions such as combining techniques, integrating machine learning, and real-time monitoring.
NONDESTRUCTIVE TESTING AND EVALUATION
(2023)
Article
Engineering, Multidisciplinary
Hasan M. Khalid, Saheed O. Ojo, Paul M. Weaver
Summary: The analysis of free vibration behavior is crucial for the design of laminated plate structures. This study presents a novel numerical solution technique to study the dynamic behavior of shear deformable laminated plates. The results demonstrate the effectiveness of the proposed method in different boundary conditions and geometric configurations.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Multidisciplinary Sciences
R. L. Lincoln, P. M. Weaver, A. Pirrera, R. M. J. Groh
Summary: This study explores the capabilities of the rapid tow shearing (RTS) process for reducing the imperfection sensitivity of axially compressed cylindrical shells. RTS enables the in situ manufacturing of embedded rings and stringers by depositing curvilinear carbon fibre tapes. By smoothly blending the material's elastic modulus and wall thickness across the cylindrical surface, the load paths can be redistributed favorably to minimize imperfection sensitivity. The use of a genetic algorithm that incorporates manufacturing imperfections and axial stiffness penalty helps maximize the reliability load of SF and RTS cylinders.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Review
Energy & Fuels
Kyungil Kong, Kirsten Dyer, Christopher Payne, Ian Hamerton, Paul M. Weaver
Summary: In recent decades, offshore wind energy has experienced significant growth due to the deployment of longer and larger wind turbine composite blades. However, these composite blades are susceptible to damage and defects, requiring thorough condition monitoring and maintenance to ensure structural integrity. Delamination, debonding, and cracks are common types of damage in wind turbine composite blades, influenced by various factors. Regular condition monitoring is necessary to assess performance degradation and reduce maintenance costs. Data-driven inspection with digital twin technology and advanced functional materials show promise in improving monitoring frameworks.
RENEWABLE ENERGY FOCUS
(2023)
Article
Engineering, Civil
Jian Xue, Weiwei Zhang, Jing Wu, Chao Wang, Hongwei Ma
Summary: This study integrates a plate-type local resonator with varying free boundaries within a plate to convert the initial low-order global vibration modes into localized vibration modes. A novel semi-analytical method is proposed to analyze the free vibration of the plate with thickness and displacement discontinuities. The results show that by applying free boundary conditions, the low-order localized vibration frequencies can be significantly reduced without affecting the low-order global frequencies.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Merve Tunay
Summary: In recent years, there has been an increasing number of studies on the mechanical properties of sandwich structures manufactured with the Fused Deposition Modeling (FDM) method. However, there is still a lack of experimental data on the mechanical characteristics of FDM-manufactured sandwich structures under different thermal aging durations. In this experiment, the energy absorption capabilities of sandwich structures with different core geometries were investigated under various thermal aging durations. The results showed that the core topology significantly influenced the energy absorption abilities of the sandwich structures.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Zi-qin Jiang, Zi-yao Niu, Ai-Lin Zhang, Xue-chun Liu
Summary: This paper proposes a crosssection corrugated plate steel special-shaped column (CCSC) that improves the bearing capacity and overall stability of structural columns by using smaller material input. Through theoretical analysis and numerical simulation, the overall stability of the CCSC under axial compression is analyzed. The design method and suggestions for the stability of CCSC are put forward. Compared with conventional square steel tube columns, the CCSC has obvious advantages in overall stability and steel consumption.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Yong Zhang, Yangang Chen, Jixiang Li, Jiacheng Wu, Liang Qian, Yuanqiang Tan, Kunyuan Li, Guoyao Zeng
Summary: A hybrid TPMS method was proposed to develop a new TPMS structure, and the mechanical properties of different TPMS structures were studied experimentally and numerically. Results showed that the hybrid TPMS structure had higher energy absorption and lower load-carrying capacity fluctuation. Further investigations revealed that the topological shape and material distribution had significant influence on mechanical properties, and the hybrid additive TPMS structure exhibited significant crashworthiness advantage in in-plane crushing condition.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Tongfei Sun, Ye Liu, Kaoshan Dai, Alfredo Camara, Yujie Lu, Lijie Wang
Summary: This paper presents a series of experimental and numerical studies on the performance of a novel double-stage coupling damper (DSCD). The effects of damper configuration, friction-yield ratio (Rfy), and loading protocol on the hysteresis performance of the DSCD are investigated. The test results demonstrate that the arrangement of ribs in the DSCD increases its energy dissipation capacity. Numerical analysis reveals that the length of the friction mechanism and the clearance between the yield segment and the restraining system affect the energy dissipation and stability of the damper.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Jeonghwa Lee, Young Jong Kang
Summary: This study investigates the local buckling behavior and strength of I-shape structural sections by considering flange-web interactions through three-dimensional finite element analysis. The study provides a more reasonable estimation of local buckling strength by considering the ratio of flange-web slenderness and height-to-width ratio, and presents design equations for flange local and web-bend buckling coefficients.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Yizhe Chen, Wenfeng Xiang, Qingsong Zhang, Hui Wang, Lin Hua
Summary: This study investigates the surface modification of a nickel plate to improve the bonding strength with carbon fiber-reinforced plastics (CFRP). The results show that different surface modification methods, including sandblasting, coupling agent treatment, and compound coupling agent treatment, significantly enhance the bonding strength of CFRP/Ni joints. The research provides insights into improving the connection between nickel and CFRP, as well as other heterogeneous materials.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Agha Intizar Mehdi, Fengping Zhang, Moon-Young Kim
Summary: A spatial stability theory of mono-symmetric thin-walled steel beams pre-stressed by spatially inclined cables is derived and its validity is demonstrated through numerical examples. The effects of initial tension, deviator numbers, inclined cable profiles, and bonded/un-bonded conditions on lateral-torsional buckling of the pre-stressed beams are investigated, with a specific emphasis on the effects of increasing initial tension.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Teng Ma, Jinxiang Wang, Liangtao Liu, Heng Li, Kui Tang, Yangchen Gu, Yifan Zhang
Summary: The structural response of water-back plate under the combined action of shock wave and bubble loads at water depths of 1-300 m was numerically investigated using an arbitrary Lagrange-Euler method. The accuracy of the numerical model was validated by comparing with experimental and theoretical results. The influences of water depth and length-to-diameter ratio of the charge on the combined damage effect were analyzed. The results show that as water depth increases, the plastic deformation energy of the water-back plate decreases, and the permanent deformation mode changes from convex to concave. When the charge has a large length-to-diameter ratio, the plastic deformation energy of the radial plate is higher than that of the axial plate, and the difference decreases with increasing water depth. Increasing the length-to-diameter ratio enhances the combined damage effect in the radial direction in deep-water environments.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Qiu-Yun Li, Ben Young
Summary: This paper investigates the flexural performance of CFS zed section members bent about the neutral axis parallel to the flanges through experimental and numerical analysis. The results show that the current direct strength method generally provides conservative predictions for the flexural strength of unstiffened zed section members, but slightly unconservative design for edge-stiffened zed section beams. The nominal flexural strengths of zed section members with edge stiffeners were found to be underestimated by 17% to 21% on average. Modified DSM formulae are recommended for the design of CFS zed section beams.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Weinan Gao, Bo Song, Xueyan Chen, Guochang Lin, Huifeng Tan
Summary: This paper presents a precise method for predicting deformation in large-scale inflatable structures, utilizing finite element modeling and laser scanning technique. The study shows a good agreement between the predictive model and non-contact measurement results.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Fei Gao, Zongyi Wang, Rui Zhu, Zhenming Chen, Quanxi Ye, Yaqi Duan, Yunlong Jia, Qin Zhang
Summary: This research investigates the mechanical properties of high-strength ring groove rivet assemblies and the load resistances of riveted T-stubs. Experimental tests reveal that Grade 10.9 rivets have higher yield strength and strain, and lower ultimate strain, making them suitable for high-strength ring groove rivet connections. Increasing the rivet diameter benefits the T-stubs, while increasing the flange thickness is not always advantageous. The Eurocode 3 method is not suitable for T-stubs connected through ring groove rivets, while the Demonceau method is conservative.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Shangchun Jiang, Liangfeng Sun, Haifei Zhan, Zhuoqun Zheng, Xijian Peng, Chaofeng Lue
Summary: This study investigates the bending behavior of two-dimensional nanomaterials, diamane and its analogous structure TBGIB, through atomistic simulations. It reveals that diamane experiences structural failure under bending, while TBGIB bends elastically before undergoing structural failure. The study provides valuable insights for the application of these materials in flexible electronics.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Qiang Zhang, Jianian Wen, Qiang Han, Hanqing Zhuge, Yulong Zhou
Summary: In this study, the mechanical properties of Q690 steel H-section columns under bi-directional cyclic loads are investigated, considering the time-varying characteristics of corrosion. A refined finite element (FE) model is built to analyze the degradation of mechanical property and failure mechanisms of steel columns with different design parameters during the whole life-cycle. The study proposes a quantitative calculation method for the ultimate resistance and damage index of steel columns, taking into account the ageing effects. The findings emphasize the importance of considering the ageing effects of steel columns in seismic design.
THIN-WALLED STRUCTURES
(2024)
Article
Engineering, Civil
Yuda Hu, Qi Zhou, Tao Yang
Summary: The magneto-thermo-elastic coupled free vibration of functionally graded materials cylindrical shell is investigated in this study. The vibration equation in multi-physical field is established and solved using the Hamilton principle and the multi-scale method. The numerical results show that the natural frequency is influenced by various factors such as volume fraction index, initial amplitude, temperature, and magnetic induction intensity.
THIN-WALLED STRUCTURES
(2024)