Article
Materials Science, Composites
Bowen Gong, Huan Wang, Martinson Nartey, Wenting Ouyang, Jing Ye, Shaoxing Qu, Hua-Xin Peng
Summary: An experimental investigation was conducted on unpinned and Z-pinned quasi-isotropic carbon fibre/epoxy laminates to understand the damage evolution and failure mechanisms under fatigue loading. The Z-pinned laminates exhibited poor fatigue behavior at low cycles but had higher stiffness. The failure modes evolved from delamination to on-axial fiber failure.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
Article
Mechanics
Andre Knopp, Elisabeth Funck, Andreas Holtz, Gerhard Scharr
Summary: The investigations conducted in this study demonstrate that the properties of z-pin reinforced laminates can be positively influenced by using circumferentially notches as a defined z-pin surface micro-structuring. The fracture mechanical properties under Mode-I crack opening loading can be significantly improved and the resulting delamination areas that occur during an impact can be effectively reduced. The residual strength properties of pinned laminates are also more favorable and can be further enhanced with the use of circumferentially notched z-pins.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Civil
Chenxi Yao, Zhenchao Qi, Wenliang Chen
Summary: In this study, a thermoplastic composite joint was formed using a thermoplastic composite fastener (TPCF), and a physics-guided neural network was developed to predict its fatigue life. Experimental results showed that TPCF was only 19.0% of the weight of a titanium rivet. Proper pressure and an 'S-shape' interlayer improved fatigue resistance. A lower cooling rate during hot-press joining increased fatigue life to 105.8 cycles. The experimental results were used as physics constraints to guide the neural network, which successfully predicted the mean and deviation of fatigue life.
THIN-WALLED STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
L. Francesconi, G. Loi, F. Aymerich
Summary: Impact and compression-after-impact (CAI) tests were conducted to evaluate the effect of z-pinning on delamination resistance and damage tolerance properties of carbon/epoxy laminate. The results showed that z-pins reduced the extent of damage for high-energy impacts and improved CAI strength. However, they degraded the residual compressive strength for lower impact energies.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Engineering, Civil
Xuebei Teng, Yingjie Xu, Weihong Zhang, Weiwei Liu, Mingxin Yin
Summary: In this study, the resistance of delamination in curved carbon fiber/epoxy composite laminates reinforced by z-pins was experimentally investigated. A cost-effective pre-hole z-pinning technique was applied to mitigate initial in-plane damage, and the effect of z-pin volume fraction and diameter on interlaminar fracture toughness and bridging behavior was evaluated through double cantilever beam testing. The mode-mixity of z-pin was determined, and the fracture toughness of curved specimens was calculated based on Timoshenko curved beam theory. The results showed that the mode-mixity varied depending on the location of z-pins, and z-pins experienced a combination of crack opening and crack sliding loads during the tests. The primary failure mode of z-pins was pull-out, with a minor portion experiencing fracture. The fracture toughness of specimens with 0.8 vol% z-pins was significantly higher compared to unpinned specimens, indicating the delamination resistance capacity of z-pins was influenced by the mixed-mode ratio.
THIN-WALLED STRUCTURES
(2023)
Article
Engineering, Manufacturing
S. Abbasi, R. B. Ladani, C. H. Wang, A. P. Mouritz
Summary: The study investigates the mechanisms and effectiveness of metallic and composite z-filaments in improving the interlaminar fatigue resistance of fibre-polymer laminates. Results show that steel z-filaments are more effective than copper filaments in resisting fatigue crack initiation and growth under interlaminar cyclic loads. Differences in crack bridging efficiency under interlaminar fatigue loading contribute to the varying extents of improvement provided by the three filaments.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2021)
Article
Engineering, Multidisciplinary
Yinhuan Yang, Manfeng Gong, Xiaoqun Xia, Yuling Tang
Summary: By conducting tensile failure experiments and numerical simulations, it was found that the joint exhibited mixed failure, with Z-pins ultimately pulling out from the adherend.
CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES
(2021)
Article
Engineering, Civil
K. Chu, K. M. A. Hossain, M. Lachemi
Summary: This study investigates the use of Engineered Cementitious Composite (ECC) as a material for Sliding Approach Slabs (SAS) to eliminate bridge end joints. The results show that ECC SAS exhibits crack control under tension and maintains good performance under long-term cyclic loading. The study also reveals the impact of the approach slab on the deflection and strain of the bridge, as well as the effect of approach settlement on the structural capacity and failure mode.
ENGINEERING STRUCTURES
(2022)
Article
Engineering, Mechanical
Prabhat Ranjan, Ashok Kumar Pandey
Summary: The study proposes an improved Winkler elastic foundation based model referred as edge effect model to obtain the pinning force. The model considers stress concentration at edges during pinning and has shown satisfactory results in both conforming and non-conforming contact cases.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Polymer Science
Chow-Shing Shin, Liang-Wei Chen
Summary: This study investigates the use of FBG sensors and CNT-doped conductive joints to monitor damage development in adhesive joints. The extent of damage is revealed by a fluorescent penetrant and correlated with the monitoring signals. The refined techniques aim to shed light on the relative merits and limitations of the two techniques.
Article
Mechanics
Weiwei Wang, Han Wang, Haijin Wang, Huiyue Dong, Yinglin Ke
Summary: A new three-dimension RVE model is proposed in this paper to optimize the design of z-pinned reinforced composite material, involving the evolution of microstructures inside the laminate to enhance delamination resistance. The simulation results demonstrate that the model can effectively investigate the effects of z-pinned process parameters on the performance of laminates.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Civil
Xuebei Teng, Yingjie Xu, Weihong Zhang, Weiwei Liu
Summary: This paper investigates the effect of pre-hole z-pinning technique on carbon fiber reinforced plastic composites joints. The results show that z-pinning improves impact resistance and residual flexural properties.
THIN-WALLED STRUCTURES
(2022)
Article
Chemistry, Multidisciplinary
Lutz Baumgarten, Thomas Szyjka, Terence Mittmann, Andrei Gloskovskii, Christoph Schlueter, Thomas Mikolajick, Uwe Schroeder, Martina Mueller
Summary: The reliability of ferroelectric HfO2- and HZO-based memory devices is strongly influenced by the choice of electrode materials. Interface conditions, such as band alignment, defect formation, and doping, are recognized as decisive factors for device performance. Hard X-ray photoelectron spectroscopy reveals two opposite scenarios of band alignment in TiN/HZO/TiN and IrO2/HZO/IrO2, explaining the conditions for stable device performance and degradation. A key condition for the stability of ferroelectric devices is identified as the alignment of the charge neutrality level with the metallic Fermi level. Oxygen-deficient HfO2-based interfaces, where the Fermi level of the metal electrode is close to the conduction band of the ferroelectric insulator, can achieve stable device performance.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Mamta Dahiya, Rohit Kumar, Dheeraj Kumar, Dinesh Kumar, Neeraj Khare
Summary: The addition of NaNbO3 nanorods to YBCO superconductor composites can enhance critical current and pinning force, attributed to the creation of artificial pinning centers by NaNbO3 nanorods. The maximum enhancement in critical current and pinning force is achieved with the addition of 0.5wt% nanorods.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Mechanical
WangSub Shin, Kyong-Ho Chang, Shazia Muzaffer
Summary: The research analyzed the fatigue performance of cruciform fillet welded joints with full and incomplete penetration under load carrying and non-load carrying conditions. It was found that welding deformation, residual stresses, and stress magnitude affect the fatigue crack initiation and fatigue life of welded structures.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Mechanics
Woo-Jin An, Cheol-Hwan Kim, Jin-Ho Choi, Jin-Hwe Kweon
COMPOSITE STRUCTURES
(2019)
Article
Mechanics
Gyu-Seok Kang, Byeong-Su Kwak, Hyeon-Seok Choe, Jin-Hwe Kweon
COMPOSITE STRUCTURES
(2019)
Article
Materials Science, Composites
Choe Hyeon-Seok, Kwak Byeong-Su, Park Seong-Min, Truong Viet-Hoai, Nam Young-Woo, Kweon Jin-Hwe
ADVANCED COMPOSITE MATERIALS
(2020)
Article
Mechanics
Won-Ho Choi, Byeong-Su Kwak, Jin-Hwe Kweon, Young-Woo Nam
COMPOSITE STRUCTURES
(2020)
Article
Mechanics
Won-Ho Choi, Byeong-Su Kwak, Yeong-Hoon Noh, Jong-Gwan Yook, Jin-Hwe Kweon, Young-Woo Nam
COMPOSITE STRUCTURES
(2020)
Article
Mechanics
Won-Ho Choi, Byeong-Su Kwak, Jin-Hwe Kweon, Young-Woo Nam
COMPOSITE STRUCTURES
(2020)
Article
Engineering, Manufacturing
Seong-Min Park, Rene Roy, Jin-Hwe Kweon, Youngwoo Nam
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2020)
Article
Engineering, Multidisciplinary
Byeong-Su Kwak, Won-Ho Choi, Yeong-Hoon Noh, Gi-Won Jeong, Jong-Gwan Yook, Jin-Hwe Kweon, Young-Woo Nam
COMPOSITES PART B-ENGINEERING
(2020)
Review
Materials Science, Composites
Van-Tho Hoang, Bo-Seong Kwon, Jung-Won Sung, Hyeon-Seok Choe, Se-Woon Oh, Sang-Min Lee, Jin-Hwe Kweon, Young-Woo Nam
Summary: Promising CF/PEKK composites were fabricated using Automated Fiber Placement. Mechanical properties, void content, and crystallinity were evaluated for four different postprocessing methods, with hot press yielding the best quality.
JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS
(2023)
Article
Materials Science, Composites
Gi-Won Jeong, Yeong-Hoon Noh, Won-Ho Choi, Joon-Hyung Shin, Jin-Hwe Kweon, Jong-Gwan Yook, Young-Woo Nam
Summary: This study presents an electromagnetic-mechanical repair patch (EMRP) method to restore the mechanical and electromagnetic wave absorption performance of a radar-absorbing structure damaged by lightning strike. The method considers the need to maintain structural integrity and electrical continuity for high repair efficiency. Experimental results validate the feasibility of using the proposed EMRP method in repairing radar-absorbing structures.
JOURNAL OF COMPOSITE MATERIALS
(2021)
Article
Mechanics
Jonathan Tapullima, Sang Hoon Song, Jin Hwe Kweon, Jin Ho Choi
Summary: The study developed a new stitching process for reinforcement in composite structures and proposed a mode II analysis to define cohesive parameters. Various stitching patterns were tested with two types of dry carbon fiber yarns as reinforcement.
COMPOSITE STRUCTURES
(2021)
Article
Materials Science, Composites
Young-Woo Truong, Viet-Hoai Hoang, Van-Tho Choe, Hyeon-Seok Nam, Jin-Hwe Kweon
Summary: This study investigated the delamination growth behavior of curved composite laminates at elevated temperatures, finding that the failure load decreased significantly with increasing temperature. The delamination propagation process varied significantly with temperature, and finite element analyses were used to determine cohesive parameters that accurately represented the delamination behavior at high temperatures. Comparisons between numerical and experimental results showed good agreement in terms of failure load and modes, with a thorough discussion on the effect of temperature on the failure mechanism.
ADVANCED COMPOSITE MATERIALS
(2022)
Article
Materials Science, Composites
Boseong Kwon, Hyeonseok Choe, Jaehyeng Jeong, Hyunwoo Ju, Jin-Hwe Kweon, Young-Woo Nam
Summary: This paper investigates the mechanical properties of carbon fiber reinforced polyetherketoneketone (CF/PEKK) thermoplastic induction-welded composite joints, using finite element modeling and simulation to analyze temperature behavior and experimental results. Single-lap shear strength tests were conducted to check weld quality, revealing that optimal process parameters could potentially improve mechanical performance.
JOURNAL OF COMPOSITE MATERIALS
(2021)
Article
Mechanics
Rene Roy, Lawrence Prince Raj, Je-Hyun Jo, Min-Young Cho, Jin-Hwe Kweon, Rho Shin Myong
Summary: In this study, the thermal response of a thin etched-foil heating film-based IPS integrated into CFRP laminates was characterized both experimentally and by thermal FEM simulation. The research revealed that by adjusting parameters such as the heater heat flux, anti-icing functionality of the IPS could be achieved.
COMPOSITE STRUCTURES
(2021)
Article
Materials Science, Multidisciplinary
Boseong Kwon, Wonwoo Choi, Hyunwoo Ju, Jin-Hwe Kweon, Young-Woo Nam
Summary: This study investigated the consolidation process of radial-type braided carbon fiber reinforced polyetherketoneketone (CF/PEKK) thermoplastic composite tubes. Different consolidation processes were evaluated, and the OML-PTFE consolidation process showed a flat surface without wrinkles and low void content, making it suitable for manufacturing thermoplastic composite tubes for actual aircraft use. Other processes resulted in high void content, making them less appropriate.
FUNCTIONAL COMPOSITES AND STRUCTURES
(2021)
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)
