Article
Forestry
Dongxia Yang, Changsheng Fan
Summary: This paper studies the mechanical properties of wood-based sandwich structures and finds that the apparent density of the structures is lower but the overall flat compressive strength is higher. The design of the core layer plays a significant role in the mechanical properties and failure modes of the structures.
Review
Construction & Building Technology
Ahmad Beng Hong Kueh, Saddam H. Abo Sabah, Diyar N. Qader, Siti Hasyyati Drahman, Mugahed Amran
Summary: Sandwich structures are increasingly utilized in engineering due to their high stiffness and low mass. This article reviews recent research advancements in the response of sandwich structures to low-velocity impact, examining both single and repetitive loading cases. The article discusses the failure modes of sandwich structures, the factors that influence their response, and provides recommendations for investigating sandwich structures using finite element analysis. The article also presents an overview of the observed impact resistance and potential future directions for sandwich structure development.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2023)
Article
Engineering, Mechanical
Arash Farshidi, Christian Berggreen
Summary: This study investigates the disbond damage growth in honeycomb cored sandwich structures under static and fatigue mixed mode loading through numerical and experimental methods. A two-dimensional finite element model and the Crack Surface Displacement Extrapolation mode separation method were used to predict face/core interface fatigue crack propagation based on a fracture mechanics analysis sub-routine. The Cycle Jump technique was employed to accelerate the fatigue analysis. Mixed mode fatigue characterization testing was performed, which generated a relationship between crack propagation rates and energy release rate amplitudes as a modified Paris Law. The numerical model was validated against experimental measurements, showing good agreement.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2023)
Article
Engineering, Civil
Zhi-jia Zhang, Xin Wei, Ke Wu, Yong-jing Wang, Zhen Jia, Qian-cheng Zhang, Feng Jin
Summary: This study investigates the bending stiffness, failure load, failure modes, and minimum mass design of square honeycomb-corrugation hybrid core sandwich structures under bending. Results show that honeycomb fillers not only change the failure mode but also enhance bending resistance significantly. The study successfully achieves minimum weight design and quantifies the effects of key factors, while comparing mechanical performances with other competing structures.
THIN-WALLED STRUCTURES
(2022)
Article
Engineering, Civil
M. V. V. S. Murthy, S. Gopalakrishnan, D. Poomani
Summary: A new two-node spectral finite element is proposed to study face sheet-core disbond in a sandwich panel. The numerical results obtained using this element are validated by comparing with commercially available finite element software simulations. The study on wave propagation characteristics and the effect of core damping on waves propagating in the panel are discussed.
THIN-WALLED STRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
Jian Deng, Xin Gong, Pu Xue, Qiaozhi Yin, Xinwei Wang
Summary: This article investigates the damage behavior of composite honeycomb sandwich panels subjected to localized low-velocity impact. A computational framework is proposed to predict failure patterns and energy absorption. Experimental validation and parametric study are conducted to explore the effects of structural parameters on the sandwich structure performance.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Chemistry, Physical
Eduardo Fischer Kerche, Agne Kairyte, Sylwia Czlonka, Amanda Albertin Xavier da Silva, Maikson Luiz Passaia Tonatto, Francisco Luiz Bresolin, Rafael de Avila Delucis, Sandro Campos Amico
Summary: Sandwich panels reinforced with Z-pins were manufactured using an optimized design strategy, which showed an increase in flexural stiffness compared to non-optimized designs. Numerical and experimental approaches were used to investigate the influence of optimal pin position and angle. The results demonstrated the significant contribution of optimal pin position and angle to the maximum load and flexural stiffness of the composites.
Article
Mechanics
Xinyu Li, Haiyang Yang, Hao Zhang, Lianhua Yin, Zhong Zhang, Hongshuai Lei, Daining Fang
Summary: Analytical models were proposed to investigate the failure mechanisms of fluted-core sandwich composite panels, and failure mode maps were constructed. Experimental and simulation results verified the accuracy of the models, and the effects of geometric variables on load-bearing capacity and failure modes were explored. The findings are significant for lightweight and load-carrying applications.
COMPOSITE STRUCTURES
(2023)
Article
Mechanics
A. R. Damanpack, M. Bodaghi
Summary: This paper introduces a new sandwich beam element for analyzing structures with a flexible core and partially delaminated regions. The element uses high-order sandwich panel theory to consider core flexibility and nonlinearities of delaminated regions, ensuring continuity conditions for displacements and rotations at the interfaces. Results show good agreement with both sandwich and 2D FE models in predicting large deformation behaviors.
COMPOSITE STRUCTURES
(2021)
Article
Mechanics
Honglei Xie, Wanjin Li, Hai Fang, Shijiang Zhang, Zhixin Yang, Yuan Fang, Feng Yu
Summary: This study fabricated curved sandwich beams (CSBs) and conducted experiments to investigate their flexural behaviors. It was found that the usage of PET foam in CSBs can prevent core shearing failure and decrease load-displacement response. The results also showed that decreasing curvature led to a decrease in the ultimate load-bearing capacity and stiffness of the CSBs.
COMPOSITE STRUCTURES
(2024)
Article
Mechanics
Liang Meng, Xinqiang Lan, Jian Zhao, Hao Li, Zemin Wang, Liang Gao
Summary: The study investigated the failure mechanisms and processes of bio-inspired corrugated sandwich structures (BCSS) manufactured by laser powder bed fusion (LPBF) under three-point bending using theoretical derivation, experimental, and finite element method (FEM). The results showed that panel buckling is the dominant failure mode, while panel yielding or core buckling is the fatal failure mode for structures whose initial failure mode is panel buckling. Furthermore, the experimental and FEM results were in good agreement with analytical predictions.
COMPOSITE STRUCTURES
(2021)
Article
Construction & Building Technology
Simmi Guptaa, H. D. Chalak
Summary: In this study, bending and free vibration analyses are conducted on sandwich FGM beams using the recently proposed HOZT. Different material gradation laws and stress distributions across the thickness are examined, revealing the distinct behavior of unsymmetric beams compared to symmetric ones. The findings provide valuable insights for future studies in this field.
STEEL AND COMPOSITE STRUCTURES
(2022)
Article
Engineering, Civil
A. Garg, H. D. Chalak, M-O Belarbi, A. M. Zenkour
Summary: This study investigates the free vibration and bending behavior of sandwich beams containing open-cell metal foam core using zigzag theory. The governing equations for free vibration and bending behavior are determined using Hamilton's principle and the principle of minimum potential energy, respectively. Three types of pore distribution are examined in this study. The influence of pore distribution, end condition, core thickness, and foam coefficients on beam behavior is studied in detail. The face sheets are assumed to be made of the same material as the foam. It is observed that the nature of pore distribution and end conditions greatly affect the behavior of the beam.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2022)
Article
Materials Science, Textiles
Yan Li, Fusheng Wang, Senqing Jia, Xiangteng Ma, Yuxue Zhang
Summary: This study aims to characterize and assess the failure modes and effects of structural parameters of honeycomb sandwich structure through experiments and numerical simulations. The research discusses the relationships between the overall stiffness and strength of honeycomb structure with parameters such as cell size and stacking sequence, identifying laminate fracture, delamination, core buckling, and wrinkling as the main failure modes. These findings have significant implications for designing high-performance sandwich structures.
FIBERS AND POLYMERS
(2021)
Article
Mechanics
Pham Van Vinh, Mohamed-Ouejdi Belarbi, Mehmet Avcar, Omer Civalek
Summary: The paper develops a novel, enhanced first-order mixed plate element (IMQ4) for static bending and free vibration analysis of functionally graded (FG) sandwich plates. The transverse shear stresses are enhanced by assuming a parabolic distribution shear stress. The proposed element, IMQ4, is free of shear-locking phenomenon and can be useful for analysis, design, and testing of FG structures. Detailed parametric analyses on factors such as layup scheme, power-law index, and side-to-thickness ratio are conducted to illustrate their impacts on the bending and free vibration of FG sandwich plates.
ARCHIVE OF APPLIED MECHANICS
(2023)
Article
Engineering, Mechanical
Arash Farshidi, Christian Berggreen, Leif A. Carlsson
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2020)
Article
Engineering, Mechanical
Vishnu Saseendran, Christian Berggreen
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2020)
Article
Engineering, Mechanical
Mohsen Rezaei, Vasileios Karatzas, Christian Berggreen, Leif A. Carlsson
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2020)
Article
Mechanics
Pietro Sabbadin, R. Massabo, C. Berggreen
ENGINEERING FRACTURE MECHANICS
(2020)
Article
Engineering, Mechanical
J. P. Waldbjoern, A. Quinlan, H. Stang, C. Berggreen
Summary: The study utilized real-time digital image point tracking feedback to control a servo-hydraulic load system during the loading of a GFRP cantilever beam, achieving higher accuracy and control. Different control configurations, as well as a combination of linear transfer function and feedback control, successfully reduced the error between theoretical displacement and actual displacement, leading to improved performance.
EXPERIMENTAL TECHNIQUES
(2022)
Article
Materials Science, Multidisciplinary
A. Moncy, J. P. Waldbjorn, C. Berggreen
Summary: This study introduced active and passive control methods for fatigue testing of composite materials, with active control showing better accuracy but lower fidelity when the real-time tracking system lost markers.
EXPERIMENTAL MECHANICS
(2021)
Review
Materials Science, Composites
Pietro Sabbadin, Christian Berggreen, Brian Nyvang Legarth, Lujin Lin
Summary: This study presents a novel test fixture for analyzing the fracture characteristics of delaminations in monolithic laminates and face-core debonds in foam core composite sandwich specimens. The results show stable crack growth in monolithic laminate specimens and highly non-linear response in sandwich specimens before crack propagation, prompting further analysis and inspection to identify the source of this behavior.
JOURNAL OF COMPOSITE MATERIALS
(2021)
Article
Mechanics
A. Moncy, O. Castro, C. Berggreen, H. Stang
Summary: This study investigates the impact of anisotropy in composite materials on the uniformity of multi-axial stress states in cruciform specimens, showing how various geometries and loading conditions can be used to design specimens with uniform stress states while considering anisotropy.
COMPOSITE STRUCTURES
(2021)
Article
Materials Science, Composites
A. Moncy, B. F. Sorensen, O. Castro, C. Berggreen, J. Glud
Summary: This paper analyzes the propagation of tunnelling cracks in composite laminates under uniaxial force-controlled and strain-controlled cyclic loading conditions. The study considers both interacting and non-interacting cracking scenarios. It is found that strain-controlled tests are suitable for studying the relationship between crack front growth rate (CGR) and energy release rate (ERR) for non-interacting cracks, while force-controlled tests are more suitable for characterizing the variation of CGR at a certain ERR value. The study also investigates the effect of crack interaction on CGR, and finds that the CGR decreases when volume averaged stresses are reduced ahead of the crack front due to shielding effect at high crack densities.
JOURNAL OF COMPOSITE MATERIALS
(2022)
Article
Engineering, Mechanical
Arash Farshidi, Christian Berggreen
Summary: This study investigates the disbond damage growth in honeycomb cored sandwich structures under static and fatigue mixed mode loading through numerical and experimental methods. A two-dimensional finite element model and the Crack Surface Displacement Extrapolation mode separation method were used to predict face/core interface fatigue crack propagation based on a fracture mechanics analysis sub-routine. The Cycle Jump technique was employed to accelerate the fatigue analysis. Mixed mode fatigue characterization testing was performed, which generated a relationship between crack propagation rates and energy release rate amplitudes as a modified Paris Law. The numerical model was validated against experimental measurements, showing good agreement.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2023)
Article
Engineering, Mechanical
Ilaria Monetto, Luca Barbieri, Christian Berggreen, Roberta Massabo
Summary: This study extends the semi-analytical expressions for analyzing fracture of layered composites to materials characterized by Dundurs' parameters describing large elastic mismatch. The results show that estimations of fracture parameters are limited when beta is not equal to zero.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Civil
Alex Quinlan, Oscar Castro, Jacob Waldbjorn, Christian Berggreen, Henrik Stang
Summary: This paper presents the design of a thin-walled composite beam for studying intra-laminar tunneling cracks at a sub-structural length-scale. The beam uses a variable thickness reinforcement in the longitudinal direction to create a gauge zone with near-uniform strains when loaded in a cantilever beam configuration. The experimental results, including strain measurements and observations of tunneling cracks, agree with numerical predictions.
THIN-WALLED STRUCTURES
(2023)
Article
Engineering, Mechanical
Lujin Lin, Christian Berggreen, Brian Nyvang Legarth
Summary: This work presents a constrained version of the Shear-Torsion-Bending (STB) test fixture, which is specially developed for testing the mode-III face/core fracture toughness of sandwich specimens. The constrained STB test fixture restrains the twisting deformation of the specimen by constraining the free end between two support rollers, leading to stable crack growth without kinking into the core. Experimental results show the occurrence of tension cracks in the core below the face/core interface before interface crack opening, impacting the mode-III fracture toughness calculation.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2023)
Article
Mechanics
A. Moncy, O. Castro, J. Glud, C. Berggreen, O. T. Thomsen, J. M. Dulieu-Barton
Summary: A multi-scale stochastic crack density evolution model is proposed for tunnelling cracks under multi-directional cyclic loading. The model accurately predicts the crack growth and saturation level, as validated by experimental data and finite element analyses.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Energy & Fuels
Jacob P. Waldbjorn, Andrei Buliga, Christian Berggreen, Find Moelholt Jensen
Summary: It has been found through research that transverse cracks in the double curved trailing edge panels of wind turbine blades are mainly caused by out-of-plane deformation of the pressure side panels. A parametrical study revealed that loading the free end of the root section with both edgewise loading and torsional moment can result in the highest peak-to-peak out-of-plane deformation of 15.9 mm.
Article
Mechanics
Xiaolong Liu, Kelian Luo, Pengcheng Gao, Tao Cong, Xi Wang, Wenjing Wang
Summary: This paper investigates the formation mechanisms of the zig-zag crack region on the shattered rim of railway wheels. The zig-zag crack region, identified as a typical region for crack propagation in rolling contact fatigue behavior, was observed using scanning electron microscopy and transmission electron microscopy. The formation of the zig-zag morphology is attributed to the periodic deflection of the propagation path relative to the initial propagation plane, caused by the limited plastic deformation zone at the crack tip. Grain refinement and secondary cracks in the zig-zag crack region are a result of the large compressive and shear stresses induced by rolling contact loading.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Anastasia Iziumova, Aleksei Vshivkov, Ivan Panteleev, Virginia Mubassarova, Oleg Plekhov, Denis Davydov
Summary: The aim of this study was to investigate the correlation between structural, acoustic emission, and thermal characteristics of fatigue crack growth in titanium alloys. Cluster analysis of the acoustic emission signals revealed two different types of signals observed during the fatigue crack development. It was experimentally demonstrated that the stored energy tends to reach an asymptotic value at the final stage of fatigue crack growth and this is correlated with the twinning process intensification in titanium alloy Ti Grade 2. A correlation was assumed between the stages of change in heat flux, the cumulative energy of the first cluster of acoustic emission signals, and the crack length.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
M. Vieira de Carvalho, I. A. Rodrigues Lopes, F. M. Andrade Pires
Summary: This study investigates the numerical challenges of fracture mechanics models within implicit quasi-static frameworks and proposes an instability criterion. The ratio of cohesive to internal power is identified as a crucial factor. Two strategies for handling fracture problems with instabilities are discussed and a comparative assessment is performed. The study also examines more complex material responses, including transformation-induced plasticity effects.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Thomas Duminy, Aurelien Doitrand, Sylvain Meille
Summary: This study conducted in situ wedge splitting tests on millimeter-size PMMA samples and proposed a method to determine the material tensile strength and critical energy release rate using digital image correlation and a full finite element implementation of the coupled criterion.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Xin Chang, Xingyi Wang, Chunhe Yang, Yintong Guo, Yanghui Wan
Summary: The influence of cyclic thermal shock and high-temperature acid etching on the Mode I fracture of shale was investigated in this study. It was found that cyclic thermal shock severely degrades the strength and fracture toughness of shale, while high-temperature acid etching treatment improves the fracture toughness. These findings are valuable for optimizing process parameters to reduce initiation pressure in deep shale formations.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Liaojun Yao, Mingyue Chuai, Zhangming Lyu, Xiangming Chen, Licheng Guo, R. C. Alderliesten
Summary: Methods based on fracture mechanics have been widely used in fatigue delamination growth (FDG) characterization of composite laminates. This study proposes appropriate similitude parameters to represent FDG behavior with different R-ratios.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Zesheng Zang, Zhonghui Li, Yue Niu, Shan Yin
Summary: This study conducted experiments and recorded signals to investigate the fracture behavior and damage evolution characteristics of coal samples. The results showed that as loading proceeds, the stress, electric potential (EP), and acoustic emission (AE) values increase, and EP and AE signals are excited when stress drops. The fracture behavior of coal samples is altered by flaw inclination, and the destruction mode becomes increasingly complicated. The damage evolution characteristics of coal samples can be evaluated and analyzed by defining the coefficient of variation (CV value) of EP and the b value of AE.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Clotilde Berdin, Nathalie Prud'homme
Summary: In this study, zirconia layers with different fractions of tetragonal phase and thicknesses were tested for multi-cracking behavior. Cracks perpendicular to the tensile direction were observed, showing a blunting effect into the substrate. The ratio of crack spacing at saturation to layer thickness decreased as the layer thickness increased. Unit cell modeling was used to establish a relationship between crack spacing and layer strength, which fell within the bounds of Hu and Evans model and was found to be insensitive to the tetragonal zirconia fraction.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Huadong Zhang, Weichen Kong, Y. H. Liu, Yuh J. Chao
Summary: Williams' series expansion crack tip solution in linear elasticity is modified to include a uniform crack face pressure. Practical methods to calculate T-stress from near crack tip stresses are outlined. The analytical results are consistent with numerical results.
ENGINEERING FRACTURE MECHANICS
(2024)
Article
Mechanics
Jiahao Kong, Haoyue Han, Tao Wang, Guangyan Huang, Zhuo Zhuang
Summary: This paper introduces a phase-field model for polymer foam materials by combining the phase-field method with the crushable foam model. The model is calibrated using experimental data and successfully simulates the fracture processes of polyurethane under different loading conditions. The study is important for the engineering applications of polymer foam materials.
ENGINEERING FRACTURE MECHANICS
(2024)
