Article
Engineering, Multidisciplinary
Justin D. Miller, Patrick Blanchard, Jeffery Dahl, Jan-Anders E. Mansson
Summary: Three-dimensional (3D) tow reinforced hybrid molding combines continuous fiber composite tow with injection overmolding to improve mechanical performance of molded components. However, the conventional modeling processes cannot accurately capture the tensile performance due to the waviness of the fibers when wrapped around load introduction points. The Hsaio and Daniel model was used to predict the elastic properties of the wavy fiber composite and showed that neglecting or modeling the waviness leads to significant differences in the predicted stiffness and strength.
COMPOSITES PART B-ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Jobst Landgrebe
Summary: Implicit stochastic models, such as deep neural networks and unsupervised foundational models, cannot be explained. This has led to the emergence of explainable AI (XAI) as a new field. However, interpretations provided by XAI only offer a subjective understanding of how a model works. In contrast, we propose certified AI (CAI) as an alternative approach, combining ontologies, formal logic, and statistical learning to obtain reliable and safe AI systems.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Aerospace
Giovanni Zucco, Mohammad Rouhi, Vincenzo Oliveri, Enzo Cosentino, Ronan M. O'Higgins, Paul M. Weaver
Summary: Cutouts in composite panels can lead to stress or strain concentrations, potentially reducing load-carrying capacity. Steering tows around cutouts using advanced techniques can alleviate such problems. Results show that a steered configuration improves buckling performance by 26% compared to straight-fiber configurations, with larger stress and strain concentrations in straight-fiber orientations under both tensile and compression loads.
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
Computer Science, Artificial Intelligence
Mercedes Garcia-Salguero, Jesus Briales, Javier Gonzalez-Jimenez
Summary: This paper introduces a fast optimality certifier for the non-minimal version of the Relative Pose problem for calibrated cameras from epipolar constraints. The certifier is based on Lagrangian duality and a novel closed-form expression for dual points, utilizing an efficient solver for local optimization on the manifold of the original problem's non-convex domain. Extensive experiments show that the certifiable solver performs well on synthetic data, consistently achieving the optimal solution and demonstrating satisfactory performance on real data.
IMAGE AND VISION COMPUTING
(2021)
Article
Mechanics
E. Madenci, A. Yaghoobi, A. Barut, N. Phan
Summary: This study presents a peridynamic (PD) approach to model progressive failure in fiber steered composites. The PD bonds enable the interaction of material points within each ply as well as their interaction with other material points in the adjacent plies. The capability of this approach is demonstrated by capturing the correct deformation field as well as the damage initiation site and its progressive growth.
ARCHIVE OF APPLIED MECHANICS
(2023)
Article
Engineering, Multidisciplinary
Umesh Marathe, Meghashree Padhan, Stephane Panier, Jayashree Bijwe
Summary: Fabric-(BD-bi-directionally) reinforced high performance polymer composites are known for their exceptional mechanical, thermal, and tribological properties, but face challenges in processing, especially for specialty polymers. This paper focuses on the development, characterization, and performance analysis of graphite fabric reinforced PAEK composites, showing that film-stacking technique excelled in most performance properties.
COMPOSITES PART B-ENGINEERING
(2021)
Article
Materials Science, Characterization & Testing
Jiahui Gu, Junchao Cao, Yuzhao Qiang, Zhenqiang Zhao, Chao Zhang
Summary: A tensile test methodology for high strain rate loading of carbon fiber tow composites was developed using the Split Hopkinson tensile bar and an ultra-high-speed camera. The tensile performance of the composites was measured under quasi-static and dynamic loading rates, and the effects of gauge length, fiber counts, and strain rate sensitivity were investigated. The results showed that the tensile strength of the composites was influenced by the length, fiber counts, and loading rates, and a modified Weibull model was proposed to evaluate these effects.
Article
Materials Science, Composites
Deao Kong, Jiajun Shi, Shaoce Dong, Chenggao Li, Bin Hong, Guijun Xian
Summary: The hygrothermal resistance of 48K and 12K carbon fibers and their CFRPs immersed in deionized water at different temperatures was analyzed and compared. The immersion caused the sizing agent on the carbon fiber surface to debond or hydrolyze, resulting in changes in the tensile strength, dispersion, and surface activity of the carbon fibers. The performance of the CFRPs was influenced by factors such as the dispersion of the fibers, surface activity, and obstructing effect on water diffusion.
POLYMER COMPOSITES
(2023)
Article
Engineering, Manufacturing
Xie Li, Jonathan Dufty, Garth M. Pearce
Summary: Automated Fibre Placement (AFP) and Filament Winding (FW) technologies offer flexibility in adjusting composite material performance, but can lead to geometric defects. This paper presents a high-fidelity geometric modelling tool for tow-wise manufactured laminates to accurately predict structural performance, demonstrated through several case studies.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2021)
Article
Engineering, Manufacturing
Ka Zhang, Haoqi Zhang, Jiang Wu, Jiayun Chen, Dongmin Yang
Summary: This study investigates the mechanism of fibre deposition in conventional 3D printing and presents an aligned fibre deposition (AFD) method to improve the fibre placement. The AFD method reduces fibre waviness and twisting, resulting in smooth filament deformation, less air voids, and fibre breakage during printing. It also improves the fibre alignment angle from ±25 degrees to ±12 degrees and reduces void content to 0.27% during straight-line deposition.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2023)
Article
Materials Science, Composites
M. Alves, L. M. Martulli, M. Kerschbaum, Y. Swolfs, S. V. Lomov Sw, S. Pimenta
Summary: This work presents a novel 3D approach for the numerical modelling of TBDCs, which generates 3D orientation tensors by adding a stochastic component and predicts the failure initiation of the materials using a physically based 3D failure criterion. Experimental results demonstrate that the proposed approach accurately predicts the mechanical properties of the materials.
COMPOSITES SCIENCE AND TECHNOLOGY
(2023)
Article
Materials Science, Textiles
Chang Xu, Jinzhen Dou, Xin Li, Guowei Shao, Zhihong Sun
Summary: Textile reinforced composites, specifically spread tow woven pierced composites (STWPs), are commonly used in thermal protection engineering due to their exceptional mechanical and physical properties. This study focused on analyzing the thermal conductivities of STWPs and proposed numerical models to accurately predict their thermal performances. The results showed that the fiber volume fraction, porosity, and interphase thermal conductance significantly affect the thermal conductivities of STWPs.
TEXTILE RESEARCH JOURNAL
(2022)
Article
Engineering, Manufacturing
Xie Li, Sonya A. Brown, Mathew W. Joosten, Garth M. Pearce
Summary: This study conducted short beam shear tests to validate the capability of tow-wise modelling (TWM) in predicting the failure mechanisms of AP-Ply laminates, achieving excellent correlation between numerical and experimental results.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2022)
Article
Materials Science, Composites
Cheng Zhang, Xueqin Zhang, Youquan Ling, Mei Liang, Huawei Zou
Summary: The spread-tow thin-ply technology improves the mechanical and thermal properties of carbon fiber reinforced polymer composites by spreading ultra-thin carbon fiber and constructing a multilayer structure on its surface. This green and non-destructive method enhances the interface properties of the composites and expands the functional application of ultrathin carbon fiber.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
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)