Article
Mechanics
Wei Zhang, Zhenyu Huang, Jianqiao Ye, Youtam
Summary: This study conducts numerical analyses on a newly developed double-layer steel-lightweight high ductility cement composite (LHDCC)-steel sandwich panel and validates the accuracy of the model through parameter studies and the development of an analytical model.
COMPOSITE STRUCTURES
(2022)
Article
Mechanics
C. A. Yan, R. Vescovini, E. L. Jansen
Summary: This paper develops a fast semi-analytical framework to study the nonlinear vibration response of plates with Variable Stiffness configuration. Spatial dependence is handled using a Ritz-like approach, while various techniques are compared for temporal dependence. The proposed framework shows effectiveness in capturing nonlinear responses and has potential to assist in the design of Variable Stiffness plates.
COMPOSITE STRUCTURES
(2021)
Article
Mechanics
Jiahai Zhang, Zhenyu Han, Yuhua Liu, Shouzheng Sun
Summary: A variable stiffness structure for grid panels of solar wing sandwich plates on satellite was designed and optimized to improve vibration resistance. By establishing a novel modal analysis model and equivalent model for sandwich plates, the modal fundamental frequencies of the VS plate were enhanced, and a method for trajectory planning was proposed. The accuracy of the manufacturing method and simulations was verified through the realization of a variable stiffness grid panel made by robotic fiber placement.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Aerospace
Yewei Zhang, Zhi Li, Kefan Xu, Jian Zang
Summary: A novel pyramid lattice sandwich structure with active variable stiffness (AVS) is proposed, which has excellent self-adjusting and active vibration reduction effect. Through analysis and comparison of the impact of different parameters, it is proven that the structure can achieve ideal vibration reduction effect.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Civil
Z. Q. Wang, S. W. Yang, Y. X. Hao, W. Zhang, W. S. Ma, X. D. Zhang
Summary: This paper presents the modeling and free vibration analysis of a variable stiffness system consisting of a truncated sandwich conical shell made of porous aluminum foam core with variable thickness and carbon fiber face sheets under simply supported boundary condition. Nonlinear dynamic equations are derived based on first-order shear deformation theory and Hamilton's principle, considering the effect of thermal environment, and the natural frequencies of the system are obtained using the Galerkin method. The influences of porosity distribution pattern, porosity coefficient, total number of layers, temperature increment, semi-vertex angle, exponent of thickness function, minimum radius-thickness, and length-thickness ratio of the core layer on the natural frequencies, modal and mode shapes are comprehensively studied through comparison and validation with existing literature results.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Mechanics
Pedram Khaneh Masjedi, Paul M. Weaver
Summary: An analytical solution is derived for the 3D static deflection of variable stiffness composite beams subject to non-uniformly distributed loads, showing high accuracy. By introducing differential equations with variable coefficients, the study efficiently captures the complex 3D static deflection of composite beams subject to non-uniformly distributed loads.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Civil
Ankita Gupta, S. Pradyumna
Summary: In this study, the nonlinear free and forced vibration analyses of variable stiffness composite laminated (VSCL) and sandwich shell panels with curvilinear fibers were conducted using a higher-order theory. The structural model considered a third-order shear deformation theory, and geometric nonlinearity was included through von Karman nonlinear strain-displacement relations. The results were compared with existing exact and analytical solutions to validate the model.
THIN-WALLED STRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
S. W. Yang, Z. Q. Wang, Y. X. Hao, W. Zhang, L. T. Liu, W. S. Ma, G. Kai
Summary: This paper examines the static bending and buckling behavior of the simply supported truncated sandwich conical shell with variable thickness core, considering various styles of porosity distribution schemes for the porous foam core.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Engineering, Aerospace
A. ChaoCorreas, H. Ghasemnejad
Summary: The study aims to provide analytical modeling techniques for describing the dynamic response of sandwich laminated structures under low velocity impact. Through analysis and experimental validation, precise analytical formulas have been developed to accurately capture the energy absorption mechanisms under different loading conditions.
AEROSPACE SCIENCE AND TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
M. Hachemi
Summary: This paper investigates the vibration analysis of variable stiffness composite laminated (VSCL) sandwich plates, utilizing layer-wise plate theory and p-version of finite element method to establish a problem formulation and new layer-wise solutions. The obtained results are compared with existing solutions, offering benchmarks for future comparisons.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2022)
Article
Materials Science, Composites
Jiakang Gan, Fenglei Li, Keqiang Li, Eric Li, Bing Li
Summary: In this work, negative-stiffness meta-sandwich structures (NSMSs) are developed based on the concept of mechanical metamaterial, and their dynamic responses under repeated high strain-rate impacts are systematically investigated using the 3D printing technique of selective laser sintering. The double curved-beam topology and remarkable impact resistance of NSMSs are analyzed theoretically, numerically, and experimentally. An analytical model is presented to predict the mechanical behavior of NSMSs, and evaluation indicators are developed to quantitatively describe the energy absorption performance. Compared with conventional honeycomb structures, NSMSs demonstrate a unique layer-by-layer failure mode and significant improvement in multiple-impact resistance capacity.
COMPOSITES SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Yinggang Li, Wen Xiao, Xiong Wu, Ling Zhu
Summary: This paper investigates the dynamic responses of sandwich plates with foam core under wedge impact. An analytical model of fully clamped foam-core sandwich plate is developed based on approximate yield criteria and rigid-perfectly plastic theory. Experimental and numerical simulations of PVC foam-core sandwich plates are conducted to verify the accuracy of the analytical prediction model. The results show that the analytical prediction results are consistent with the experimental and numerical results, and the impact force, deformation distribution, and permanent deformations can be accurately predicted. The theoretical study on the geometrical parameters indicates that the deformation reaches its maximum at an aspect ratio of 1, and the permanent deformation decreases with an increase in wedge width and foam core thickness.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Zhao Jing, Lei Duan, Biao Li
Summary: A novel variable stiffness optimization algorithm is proposed for vibration optimization of variable-stiffness composite plates. The algorithm employs a linear variation fiber path function and incorporates a 2D-sampling optimization method to generate a good initial point. By dividing the fiber angles into two groups, the VSO algorithm designs the laminate sequentially and iteratively, improving the stiffness of the VSC plate part by part. The algorithm demonstrtes higher efficiency and similar robustness compared to conventional optimization methods, and it can improve the maximum fundamental frequency of VSC plates by about 10%.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Engineering, Civil
S. A. M. Ghannadpour, F. Rashidi
Summary: This article investigates the nonlinear and post-buckling behaviors of variable-stiffness plates with and without square and rectangular cutouts, under different boundary conditions. It examines the effects of the presence, size, shape, and location of the cutout on the nonlinear behavior of the plates subjected to uniaxial compressive loads. The study models the plate with cutout by dividing it into sub-plates and connecting them using a plate assembly technique. The results are validated through finite element analysis.
THIN-WALLED STRUCTURES
(2022)
Article
Robotics
Dickson Chun Fung Li, Zerui Wang, Jianshu Zhou, Yun-Hui Liu
Summary: Jamming technologies are a promising approach for variable stiffness mechanisms, but face limitations such as restricted stiffening capacity and position. This article introduces a variable stiffness mechanism that achieves rapid transition from flexible to rigid states with biocompatibility and enhanced stiffening capacity, utilizing a novel strategy called variable stiffness reconfiguration. This approach provides a new solution for controlling stiffness and adjusting stiffening regions in soft robotics, enabling complex manipulator postures and customized grippers.
Article
Mechanics
Rawan Aqel, Patrick Severson, Rani Elhajjar
Summary: A novel core splice joint configuration for composite sandwich structures is studied and proposed to improve the strength and toughness. Experimental and numerical efforts show that this configuration can significantly increase the ultimate strength by 13% to 51% and the toughness by 2% to 35%.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Xianheng Wang, Cong Chen, Jinsong Zhang, Xinming Qiu
Summary: In this paper, a new form-finding method based on spatial elastica model (FMSE) is proposed for elastic gridshells. The method integrates the deformations of elastic rods into the overall deformation of the gridshell, and solves a set of transcendental equations using the quasi-Newton method to ensure the deformation satisfies the given boundary conditions. The method is validated through experiments and expected to have potential applications in the investigations of elastic gridshells.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Hao Huang, Zitong Guo, Zhongde Shan, Zheng Sun, Jianhua Liu, Dong Wang, Wang Wang, Jiale Liu, Chenchen Tan
Summary: The conventional evaluation of 3D braided composites' mechanical properties through numerical and experimental methodologies hinders material application due to the expenses, time constraints, and laborious efforts involved. This study establishes a multi-scale finite element model and a surrogate model for predicting the elastic properties of 3D4D rotary braided composites with voids. By optimizing a neural network model, the results are validated and provide valuable insights into the microstructure and properties of these composites.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Xinyu Li, Hao Zhang, Haiyang Yang, Junrong Luo, Zhongmin Xiao, Hongshuai Lei
Summary: Due to their excellent mechanical properties and design flexibility, fluted-core composite sandwich structures have gained significant attention in aerospace and rail transit applications. This study investigated the free-vibration characteristics and optimized design of composite fluted-core sandwich cylinders through theoretical models and experimental tests.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Chao Li, Chunzheng Duan, Xiaodong Tian, Chao Wang
Summary: A mechanistic model considering the bottom edge cutting effect and the anisotropic characteristics of the material is proposed in this paper to accurately predict cutting forces. The model was validated through a series of milling experiments and can be used to predict the cutting force of various parts of the cutter and any feed direction.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Camila Sanches Schimidt, Leopoldo Pisanelli Rodrigues de Oliveira, Carlos De Marqui Jr
Summary: This work investigates the vibro-acoustic performance of graded piezoelectric metamaterial plates. The study shows that piezoelectric metamaterial plates with reconfigurable properties can provide enhanced vibration and sound power attenuation.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Jun Ke, Li-jie Liu, Zhen-yu Wu, Zhong-ping Le, Luo Bao, Dong-wei Luo
Summary: Compared with other green natural fibers, ramie has higher mechanical properties and lower cost. In this study, ramie and glass fiber are made into composite circular tubes. The results show that the hybrid circular tube with ramie and glass fiber has improved torsional mechanical properties and reduced weight and cost. The failure mechanisms are affected by the loading direction and the content of each fiber.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Natalia Pingaro, Gabriele Milani
Summary: This paper proposes an enhanced analytical model for predicting the behavior of FRCM samples tested under standard tensile tests. The model takes into account the interaction between fibers and matrix through the interface, and assumes different material properties at different phases. By solving a second order linear differential equation, an analytical solution can be obtained. The model is validated with experimental data and shows good predictability.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Jialiang Fan, Anastasios P. Vassilopoulos, Veronique Michaud
Summary: This article investigates the effects of voids, joint geometry, and test conditions on the fracture performance of thick adhesive Double Cantilever Beam (DCB) joints. It concludes that grooved DCB joints with low void content tested at low displacement rates showed stable crack propagation without significant crack path deviation.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Auwalu I. Mohammed, Kaarthikeyan Raghupathy, Osvaldo De Victoria Garcia Baltazar, Lawson Onokpasah, Roger Carvalho, Anders Mogensen, Farzaneh Hassani, James Njuguna
Summary: This study investigates the performance of composite pressure vessels under damaged and undamaged conditions, providing insights into their reliability and residual strength capabilities. The results demonstrate that the damage profile and its effect on compressive strength are similar between damaged and non-damaged cylinders. When subjected to quasi-static compression, the polyethylene liner absorbs enough elastic strain energy to recover without plastic deformation. Additionally, quasi-static compression has little to no influence on the axial strength of the cylinders. The damage characterization reveals fiber breakage, delamination, local buckling, and brooming failure. This study has direct implications for the safety design tolerances, manufacturing strategies, and operational failure conditions of composite overwrapped pressure vessels (COPVs).
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Muhammad Irfan Shirazi, Samir Khatir, Djilali Boutchicha, Magd Abdel Wahab
Summary: Structural health monitoring is important to ensure the safety of components and structures. This study proposes a method using finite element models and 1D-CNN network to extract and classify vibration responses for crack detection. The results show that the proposed approach is effective in real-time damage detection.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Maryam Mirsalehi, Kiarash Kianpour, Sharif Shahbeyk, Mohammad Bakhshi
Summary: This study comprehensively investigates the one-way response of 3D-woven sandwich panels (3DWSPs) and their interfering parameters, providing interpretation of elastic and failure results, failure maps, and reliable theoretical models for linear elastic response and observed failure mechanisms.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Yiming Zhao, Zhonggang Wang, Zhigang Yang, Bin Qin
Summary: The paper proposes a Ritz and statistical energy analysis (Ritz SEA) hybrid method for calculating rectangular plate acoustic vibration coupling in the mid-frequency range. This method combines the fast convergence and ability to handle arbitrary boundary conditions of the Ritz method with the power flow equation of the statistical energy analysis method. The results show that this approach effectively filters out random fluctuations in mid-frequency domains while demonstrating exceptional stability and precision.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Joao Henrique Fonseca, Woojung Jang, Dosuck Han, Naksoo Kim, Hyungyil Lee
Summary: This study addresses the enhancement of an injection-molded fiber-reinforced plastic / metal hybrid automotive structure and its plastic injection molding process through the integration of the finite element method, artificial intelligence, and evolutionary search methods. Experimental validation of finite element models, the generation of a database through orthogonal array and Latin hypercube methods, and the training of artificial neural networks are conducted. The genetic optimization algorithm is then applied to identify optimal process parameters. The results show significant reduction in product warpage and manufacturing time while maintaining structural strength, contributing to the advancement of composite automotive structures with superior quality.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Alessandro Vescovini, Carina Xiaochen Li, Javier Paz Mendez, Bo Cheng Jin, Andrea Manes, Chiara Bisagni
Summary: This paper presents a study on six single-stringer specimens manufactured using the card-sliding technique with non-crimp fabrics and adopting a Double-Double (DD) stacking sequence. The specimens were tested under compression loading conditions to investigate post-buckling and failure in aerospace structures. Experimental results and numerical simulations were compared to analyze the behavior and failure modes of the specimens. The study found promising evidence of a viable solution to optimize aeronautical structures and enhance resistance to skin-stringer separation, particularly with the use of tapered flanges.
COMPOSITE STRUCTURES
(2024)