Article
Engineering, Multidisciplinary
Mohit Pundir, Guillaume Anciaux
Summary: The evolution of crack surfaces in materials is closely related to the self-contact between them, with developed contact forces playing a significant role in stress mitigation and stress transfer. A hybrid cohesive-contact approach is proposed to model fracture processes with cohesive elements while enforcing contact and friction constraints through a penalty-based method, overcoming limitations of traditional approaches for large relative displacements. The new approach provides a reliable and physically based numerical model for studying crack propagation along rough surfaces.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2021)
Article
Materials Science, Composites
Jagan Selvaraj, Luiz F. Kawashita, Mehdi Yasaee, Gordon Kalwak, Stephen R. Hallett
Summary: A novel cohesive element formulation is proposed for modelling composite delamination, offering increased stability and requiring fewer elements. This new formulation combines nodal rotations and multiple integration points to improve the accuracy of delamination propagation simulation.
COMPOSITES SCIENCE AND TECHNOLOGY
(2021)
Article
Mechanics
Sasanka Kakati, D. Chakraborty
Summary: This paper investigates the oblique low velocity impact behavior of clamped GLARE plates and analyzes the influence of obliquity and coefficient of friction on the impact mechanism and extent of interfacial delamination.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2023)
Article
Engineering, Mechanical
Jeffrey M. Staniszewski, Steven E. Boyd, Travis A. Bogetti
Summary: Ultra-high molecular weight polyethylene (UHMWPE) composites are commonly used in protective armor systems, and the design of such systems has traditionally relied on empirical studies, which can be costly and time consuming. A multi-scale, finite element-based representative volume element (RVE) approach has been developed to capture the ply-level material nonlinearity and strain-induced fiber reorientation of UHMWPE composites subjected to low-velocity impact (LVI) loading. This approach accurately predicts the impact performance of UHMWPE composite materials and can be used to evaluate various laminate architectures and processing conditions.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Mechanics
Tamer Tahir Ata, Demirkan Coker
Summary: The dynamic failure of a 30-ply curved unidirectional CFRP laminate under quasi-static moment/axial combined loading was numerically investigated. Dynamic delamination initiated at the maximum radial stress location, with crack propagation observed to be intersonic in the arm regions.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Multidisciplinary
L. Carreras, B. L. V. Bak, S. M. Jensen, C. Lequesne, H. Xiong, E. Lindgaard
Summary: Adopting effective numerical tools can reduce design, certification, and maintenance costs by predicting damage effects on structures accurately. However, the validation of tools for assessing progressive delamination under high-cycle fatigue is insufficient, as they are rarely tested on realistic benchmark specimens. This study presents a benchmark test on a real wind energy industry specimen, demonstrating varying crack growth rates and front shape, which are more representative of in-service structures. The test is also simulated using a commercially available tool based on a cohesive zone model approach, which can replicate the experimental results regarding crack front evolution and location.
COMPOSITES PART B-ENGINEERING
(2023)
Article
Mechanics
Congzhe Wang, Anastasios P. Vassilopoulos, Thomas Keller
Summary: This study numerically investigated the two-dimensional delamination growth in FRP laminates under Mode I loading condition using finite element analyses. The results showed that flatter pre-crack or loading zone shapes could result in higher initial structural stiffness and less uniform distribution of the strain energy release rate along the pre-crack perimeter. The final crack shape was dependent on the loading zone shape and area, but the effects were relatively weak.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Automation & Control Systems
Lhoucine Boutrih, Lanouar Ben Ayed, Mohammed Nouari
Summary: Structures involving assembled materials such as titanium/composite are commonly used in the aeronautical industry due to their high mechanical properties, but machining difficulties are often encountered due to their poor machinability. A numerical model considering different phases of the assembly has been developed, which revealed that the cutting sequence is crucial in preventing interface delamination. The study also found two levels of cutting forces related to the ductile behavior of the titanium phase and the brittle behavior of the composite phase during the orthogonal cutting process.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Mechanics
Xie Li, Sonya A. Brown, Mathew W. Joosten, Garth M. Pearce
Summary: This paper presents an efficient and novel cohesive contact network approach for modelling multiple mesoscale composite failures. The proposed method successfully captures various failure modes, such as matrix cracking, delamination, and fibre rupture, by forming an interconnected cohesive contact network. Numerical studies demonstrate the feasibility and efficiency of the approach, with excellent agreement with published results.
COMPOSITE STRUCTURES
(2022)
Article
Mechanics
Mathilde Zani, Daniele Fanteria, Anita Catapano, Marco Montemurro
Summary: This study presents a consistent energy-based cohesive zone model for simulating the mode I delamination behavior of FUMD laminates and validates the effectiveness of the model through experiments. The numerical simulations closely replicate the delamination behavior of DCB specimens, but with some differences compared to experimental results.
COMPOSITE STRUCTURES
(2022)
Article
Mechanics
Amin Ekhtiyari, Mahmood M. Shokrieh
Summary: The study evaluates the influence of local separation rate on stress distribution near the crack tip and practical traction-separation laws for double-cantilever beam specimens under different loading rates. The bridging laws indicate that maximum bridging traction decreases with increasing separation rate. The proposed model, implemented in ABAQUS, demonstrates good agreement between finite element and experimental results, verifying its reliability and accuracy in accounting for rate effects in presence of large-scale fiber bridging.
COMPOSITE STRUCTURES
(2022)
Article
Chemistry, Multidisciplinary
Luis M. Ferreira, Carlos A. C. P. Coelho, Paulo N. B. Reis
Summary: This study investigates the influence of interface stiffness and strength on the low-velocity impact response of woven-fabric semicylindrical composite shells using finite element models. Intralaminar damage is accounted for with the ABAQUS software, while interlaminar damage is addressed with cohesive surfaces. Results show that interface stiffness has a negligible effect on force and energy histories, but significantly impacts delamination predictions. Increasing normal interface strength from 15 MPa to 30 MPa results in an 8% increase in maximum force and a reduction in delaminated area. The findings provide guidelines for accurate and efficient computation of delamination.
APPLIED SCIENCES-BASEL
(2023)
Article
Mechanics
Bing Zhang, Giuliano Allegri, Stephen R. Hallett
Summary: This paper presents a novel numerical technique for modelling fatigue delamination growth in fibre reinforced composites. The simulation approach can describe fatigue delamination under various loading conditions. The method combines twin cohesive zone models with an artificial neural network. The application of this technique has been successfully demonstrated through verification and validation.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Chemistry, Physical
Houcheng Fang, Di Wang
Summary: This study verifies the delamination damage in thick-walled composite-overwrapped pressure vessels through establishing models for composite delamination damage and in-plane damage. The delamination failure processes and the first occurrence of delamination failure were simulated and analyzed using a tiebreak contact algorithm. The locations of significant delamination phenomena under different layup angles were predicted, and the differences in structural strength between different laying methods were compared.
Article
Engineering, Mechanical
Chen Fu, Xi Wang
Summary: This study proposes a novel three-linear cohesive zone model superposed by two bilinear laws for modeling mixed-mode delamination with large scale fiber bridging. A new method to determine bridging strength by applying varied values in different regions of the prearranged delamination path is developed, based on the concept of fracture process zone (FPZ) length. Simulation results show good agreement between predicted load-displacement responses and experimental results, validating the efficiency of the established CZM and bridging strength determination method in predicting delamination behaviors under both pure mode and mixed-mode loadings.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
Farnoosh Farhad, David Smyth-Boyle, Xiang Zhang
Summary: This study focuses on understanding the fatigue behavior of X65 steel, particularly the ability to predict crack initiation from corrosion pits. Experimental tests conducted in a corrosive environment using bespoke laboratory apparatus show that the proposed model can effectively predict crack initiation life.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Mechanical
Abdul Khadar Syed, Xiang Zhang, Armando Caballero, Muhammad Shamir, Stewart Williams
Summary: This study investigates the influence of two different deposition strategies on the tensile and high cycle fatigue properties of wire + arc additive manufactured Ti-6Al-4V alloy. The oscillation build had lower static strength but similar elongation values compared to the parallel pass build. Anisotropic elongation values were observed due to the presence of columnar primary 13 grains, with vertical samples showing higher elongation values parallel to the primary grains. Fatigue strength was comparable to wrought materials and greater than typical cast materials, with crack initiation mostly from pores and microstructural features in the samples.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Mechanics
Emre Akgun, Xiang Zhang, Tristan Lowe, Yanhui Zhang, Matthew Dore
Summary: Defects in metal additive manufacturing play a significant role in causing failure under cyclic loading, with crack-initiating defects often located at the lower end of a positive-skewed size distribution and showing a tendency towards the free surface. By measuring fatigue crack growth rates using the replica technique, it was found that crack initiation life from porosity can contribute to at least 50% of the total fatigue life. These findings challenge the common assumption of crack initiation from the very first cycle and emphasize the importance of considering defects in predicting fatigue life.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Engineering, Manufacturing
Karan S. Derekar, Bilal Ahmad, Xiang Zhang, Sameehan S. Joshi, Jonathan Lawrence, Lei Xu, Geoff Melton, Adrian Addison
Summary: This study investigates the formation and distribution of residual stress in aluminum alloy 5183 during wire arc additive manufacturing (WAAM). The findings show that substrate thickness has a significant influence on the distribution of residual stress along the deposit height, with the majority of the deposit exhibiting tensile stress and the substrate showing compensating compressive stress.
JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME
(2022)
Article
Materials Science, Multidisciplinary
Bilal Ahmad, Xiang Zhang, Hua Guo, Michael E. Fitzpatrick, Leonor MacHado Santos Carvalho Neto, Stewart Williams
Summary: This paper investigates residual stress in WAAM Ti-6Al-4V walls built using different deposition strategies, namely single bead, parallel path, and oscillation path. The effects of interlayer hammer peening and interlayer temperature on residual stress are also examined. The findings show that the oscillation-path wall has the lowest residual stress values, while the single bead walls experience significant reduction in residual stress after removing the substrate.
Article
Materials Science, Multidisciplinary
Dibakor Boruah, Xiang Zhang
Summary: The study found that post-deposition solution treatment and ageing (STA) significantly improves the adhesive strength of cold sprayed Ti6Al4V coatings on Ti6Al4V substrates, particularly achieving over 520% improvement on ground substrates with a measured value exceeding 766 MPa. Additionally, STA increases the level of interfacial mixing, leading to better adhesion performance, reaching 81% of the ultimate tensile strength of Ti6Al4V.
Correction
Materials Science, Multidisciplinary
Dibakor Boruah, Xiang Zhang
Review
Materials Science, Multidisciplinary
Muhammad Arshad, Mohamed Amer, Qamar Hayat, Vit Janik, Xiang Zhang, Mahmoud Moradi, Mingwen Bai
Summary: High-entropy materials and coatings are novel materials with unique structures and excellent mechanical properties. High-entropy coatings are particularly important for high-temperature applications, and the development cycle of these coatings has been significantly shortened by advanced technologies. The addition of alloys plays a key role in improving the performance of coatings.
Article
Materials Science, Multidisciplinary
Dibakor Boruah, Xiang Zhang, Philip McNutt, Raja Khan, Henry Begg
Summary: This study investigates the effect of various post-deposition thermal treatments on the tensile properties of cold spray deposited titanium alloy Ti6Al4V, and finds that solution treatment and ageing process significantly improves the ultimate tensile strength.
Article
Materials Science, Multidisciplinary
Mohamed Amer, Nicholas Curry, Qamar Hayat, Rohit Sharma, Vit Janik, Xiang Zhang, Jon Nottingham, Mingwen Bai
Summary: A new multi-layered thermal barrier coating system was developed using suspension plasma spray to improve thermal cycling performance. Cracking behavior of the coating after thermal exposure was studied, revealing different crack types and their relationship with thermal expansion mismatch and increased thermally grown oxide thickness. The reduction in bond coat hardness was linked to thermally activated grain growth. The increased hardness and elastic modulus of the ceramic layers contributed to interfacial cracks.
Article
Engineering, Mechanical
Abdul Khadar Syed, Rob Plaskitt, Michelle Hill, Zsolt Pinter, Jialuo Ding, Robert Zboray, Stewart Williams, Xiang Zhang
Summary: This paper investigates the cyclic deformation behavior and fatigue properties of a wire + arc additive manufactured Ti-6Al-4V alloy. Compared to Ti-6Al-4V alloys produced by other additive manufacturing processes, the material used in this study has a coarser primary columnar beta grain structure and alpha microstructure. Fatigue tests were conducted on specimens with horizontal and vertical orientations. The vertical samples, where the loading axis was parallel with the primary columnar beta grains, showed slightly higher fatigue life and a higher cyclic softening rate compared to the horizontal samples. No porosity defects were found, and cracks initiated from either the alpha laths or alpha/beta interface due to cyclic slip localization.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Chemistry, Physical
Francesco Bianchi, Yiding Liu, Adam M. Joesbury, David Ayre, Xiang Zhang
Summary: This paper presents a finite element model for predicting the performance and failure behaviour of a hybrid joint assembling fibrous composites to a metal part with reinforcement micro pins for enhancing the damage tolerance performance. A unit-strip model using the cohesive elements at the bond interface is employed to simulate the onset and propagation of debonding cracks. Two different traction-separation laws for the interface cohesive elements are employed, representing the fracture toughness properties of the plain adhesive bond and a pin-reinforced interface, respectively. This approach can account for the large-scale crack-bridging effect of the pins. It avoids using concentrated pin forces in the numerical model, thus removing mesh-size dependency, and permitting more accurate and robust computational analysis. Lap joints reinforced with various pin arrays were tested under quasi-static load. Predicted load versus applied displacement relations are in good agreement with the test results, especially for the debonding onset and early stage of crack propagation.
Article
Chemistry, Physical
Dibakor Boruah, Nele Dewagtere, Bilal Ahmad, Rafael Nunes, Jeroen Tacq, Xiang Zhang, Hua Guo, Wim Verlinde, Wim De Waele
Summary: This study demonstrates the capability of the DIC technique in evaluating full-field residual stresses in WAAM components. The bending deformation during unclamping of WAAM parts was monitored using DIC, and the residual stresses were calculated from the captured strain field. The results were verified with an analytical model and validated using established residual stress measurement techniques.
Article
Engineering, Mechanical
Jin Ye, Abdul Khadar Syed, Xiang Zhang, Eloise Eimer, Stewart Williams
Summary: Additive manufacturing (AM) of Al-Mg-Sc alloys is popular in the aerospace industry due to their high specific strength and suitability for AM processes. This study investigated the fatigue crack growth behavior in an Al-Mg-0.3Sc alloy made by wire and arc additive manufacturing. The crack growth rate showed anisotropy due to grain size and microstructural effects at lower load ratio, but became isotropic when the stress intensity factor range exceeded 10 MPa m(1/2). At higher load ratio, the crack growth rate was isotropic with a lower threshold stress intensity factor range.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Chemistry, Physical
Muhammad Shamir, Xiang Zhang, Abdul Khadar Syed, Wayne Sadler
Summary: This paper discusses the impact of as-deposited surface conditions on the fatigue strength of an additively manufactured titanium alloy. The study quantifies the local stress concentration caused by surface waviness and conducts fatigue tests under bending loads. The research emphasizes the applicability of predictive methods, with the fracture mechanics approach delivering accurate predictions. The importance of surface machining and polishing depends on the specific application and service load levels. This research demonstrates the effectiveness of the fracture mechanics approach in predicting fatigue life and aiding decision making on surface machining.
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)
