Theoretical and Applied Fracture Mechanics最新文献

{"title":"Potential fracture behaviors of a crack tip under mixed Mode-II/III loading","authors":"P.C. Chang ,&nbsp;Y.J. Xie","doi":"10.1016/j.tafmec.2025.104863","DOIUrl":"10.1016/j.tafmec.2025.104863","url":null,"abstract":"<div><div>Based on the three-dimensional geometrical modelling of multiple-crack initiations, present research demonstrates that there are four energy-based driving forces, which have different directions and different action regions or points around a crack tip under mixed Mode-II/III loading. These four energy-based driving forces compete to drive crack tip cracking and control the fracture configurations of the crack tip. By using the Griffith’s fracture criterion, when any one or two of the four energy-based driving forces reach the critical value of boundary cracking, a crack or two cracks will initiate in the form of crack kinking, symmetrical branching, side-branching or extension. There are multiple forms of the potential fracture configurations. The concerned fracture toughness and <em>K</em>-based fracture criterion for crack kinking and branching are found. The method to trigger crack branching is discussed. The notch effect on crack branching is investigated based on the present method.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"137 ","pages":"Article 104863"},"PeriodicalIF":5.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and numerical investigations on the synergistic effect of plasma nitriding and notch size on the fatigue properties of AISI 4140 steel","authors":"F. Yılan ,&nbsp;H. Kovacı","doi":"10.1016/j.tafmec.2025.104864","DOIUrl":"10.1016/j.tafmec.2025.104864","url":null,"abstract":"<div><div>Engineering structures across various sectors frequently experience fatigue damage under operational conditions, which significantly reduces their operational lifespan. Moreover, fatigue strength of the materials reduces when they have geometries such as notches and sharp corners because they constitute stress concentrations. On the other hand, different surface treatments can efficiently increase in managing the lifetime and performance of materials. In the current study, the fatigue properties of untreated and plasma nitrided notched steel samples were compared through numerical analyses and fatigue experiments. For this investigation, fatigue test specimens with different notch sizes made out of AISI 4140 steel were plasma nitrided at 460 °C and 535 °C for 9 h in a glow discharge environment. The specimens were analysed using XRD, SEM, and microhardness tester to ascertain their structural, morphological, and mechanical characterization. The notch fatigue behaviour of nitride samples was analysed numerically by the Finite Element Analysis (FEA). Furthermore, a rotational bending fatigue test system was utilized to conduct fatigue tests and consequently, fatigue date obtained from experimental results and FEA were compared. It was found that the thicknesses of compound layer and diffusion zone, compressive residual stresses, and hardness enhanced as the process temperature increased. Additionally, an increase of by up to 110 % was obtained in the notch fatigue resistance of the specimens under constant amplitude loading. According to the results obtained, it was observed that there were acceptable errors between the experimentally obtained values and the values obtained from the FEA. The results show that in all plasma nitrided notched samples, the fatigue crack initiation shifted towards the core and thus the fatigue strength increased, and especially at the increasing plasma nitriding process temperature, the R4 and R8 notch geometries exhibited better fatigue performance improvement than the other samples.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"137 ","pages":"Article 104864"},"PeriodicalIF":5.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Higher-order asymptotic solution of bi-material V-notch with dissimilar hardening coefficients under plane strain condition","authors":"Zahra Nasiri,&nbsp;Mahdi Fakoor","doi":"10.1016/j.tafmec.2025.104872","DOIUrl":"10.1016/j.tafmec.2025.104872","url":null,"abstract":"<div><div>In this study, the first two terms of the asymptotic expansion of the stress field at the corner of the interface of two elastic–plastic materials with dissimilar hardening coefficients have been extracted under plane strain conditions. The total deformation theory of plasticity and hardening behavior in the form of power law has been used to obtain the general stress–strain relationship. The eigenvalue and mode-mix parameter related to the first term and the second term of the stress expansion according to the angle of the material that has a higher hardening coefficient have been extracted for different hardening coefficients. Considering the first two terms, unlike the first term where the eigenvalue is not dependent on the properties of the material with the lower hardening coefficient, the eigenvalue of the second term may depend on the properties of both materials. To obtain the coefficients of the first term and the second term of the stresses obtained from the asymptotic solution, the root mean square (RMS) of the differences between the stresses obtained from the asymptotic solution and the finite element (FE) solution are minimized in the shear loading condition. The conformity of the results obtained from the asymptotic solution with the results obtained from the FE solution at different angles and for different hardening coefficients has been checked. The obtained results show that with the increase of the angle and the hardening coefficient of the material which has a higher hardening coefficient, the discrepancy between the results of the asymptotic solution and the FE solution increases, and as a result, the need for higher order terms increases. The greater difference mode-mix parameter of the two materials causes a greater difference between the asymptotic results and the FE results in the first material, and this discrepancy is reduced by considering higher-order terms.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"137 ","pages":"Article 104872"},"PeriodicalIF":5.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143386545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fracture surface morphology characteristics study of marble containing randomly distribution fracture under 3D digital reconstruction","authors":"Dan Huang ,&nbsp;Zilong Xiao ,&nbsp;Qingping Jin ,&nbsp;Zheng Wu","doi":"10.1016/j.tafmec.2025.104870","DOIUrl":"10.1016/j.tafmec.2025.104870","url":null,"abstract":"<div><div>Fractured rocks, common in engineering materials, are significantly influenced by fissure distribution. This paper presents a series of experiments conducted to quantitatively evaluate the fracture surface morphology of marble specimens with different fracture network angles (30°, 45°, 60°, and 75°). Subsequently, the fracture surfaces of the failed specimens were digitally reconstructed from point cloud data obtained via three-dimensional (3D) laser scanning. A high-speed camera and scanning electron microscopy (SEM) were used to observe the rupture evolution and study the fracture micromorphology, respectively. The Joint Roughness Coefficient (JRC) quantitatively evaluated the two-dimensional morphology, while Skewness (S_sk), Kurtosis (S_ku), Interface Expansion Area Ratio (S_dr), and Maximum Volume Capacity (VMF) assessed the three-dimensional morphology of the fracture surface. A comparative analysis of two-dimensional and three-dimensional fracture surface morphology was conducted. The results indicate that the roughness of tensile crack is smaller than shear crack, the fractal dimension of tensile crack is smaller than shear crack. As the dip angle of prefabricated fractures increases, the primary failure mode of marble specimens transitions from tensile to mixed tensile and shear, and finally to shear failure. The JRC value for shear fracture surfaces exceeds that for tensile failure surfaces. Regression analysis revealed a high correlation between S_dr and JRC for both two-dimensional and three-dimensional fracture surface morphologies.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"137 ","pages":"Article 104870"},"PeriodicalIF":5.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143386546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on notch stress–strain response of blunt side-notched specimen with finite residual width","authors":"Mingchao Ding ,&nbsp;Shuguang Bian ,&nbsp;Pengkuo Lei ,&nbsp;Jiaxing Huang ,&nbsp;Gengliang Liu ,&nbsp;Lipo Yang ,&nbsp;Liming Wang","doi":"10.1016/j.tafmec.2025.104862","DOIUrl":"10.1016/j.tafmec.2025.104862","url":null,"abstract":"<div><div>The stress–strain curve at the notch root can be an essential basis for studying the elastic–plastic deformation behavior of notched structure. However, current notch stress–strain studies rarely consider the effect of a finite residual size at the notch root. The blunt side-notched specimens with finite residual width are designed in this work. The material of side-notched specimen is the TC4 titanium alloy. The notch-root strain is measured using the 3D-DIC and an elastic–plastic finite element analysis is performed. It is found that the notch constraints of the finite residual width side-notched specimens are plane stress, which may not be affected by the notch-root radius of curvature. Experiment verification shows that both Neuber’s rule and ESED would underestimate the notch root strain in the plastic stage, and the main reason is that the stress concentration caused by the finite residual width is not considered. To compensate for the deficiency of the traditional method of describing stress concentrations using only <em>K</em>_t, a geometric concentration factor <em>K</em>_g is proposed. <em>K</em>_g can simultaneously reflect the effect of both <em>K</em>_t and the finite residual width on plastic deformation. By introducing the <em>K</em>_g, the accuracy of Neuber’s rule and ESED in describing notch stress–strain has been significantly improved.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104862"},"PeriodicalIF":5.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on mode I fracture response of adhesive joints subjected to systematic creep damage","authors":"Jamal Bidadi,&nbsp;Hamed Saeidi Googarchin","doi":"10.1016/j.tafmec.2025.104868","DOIUrl":"10.1016/j.tafmec.2025.104868","url":null,"abstract":"<div><div>Structural adhesive joints are effective strategy for constructing lightweight, cost-efficient components. Evaluating their long-term performance is crucial for designing durable and robust bonded systems. Understanding time-dependent phenomena like creep and its impact on the mechanical and fracture behavior of adhesives provides valuable insights for improved design. Creep loading significantly influences the strength, deformation, and fracture response of bonded structures over their service life. This study investigates the creep behavior and mode I fracture response of modified double-cantilever beam (MDCB) adhesive joints subjected to sustained tensile loads, focusing on two primary factors: creep stress level and creep duration. Creep tests were conducted on MDCB specimens at stress levels of 20 %, 30 %, 40 %, 50 %, and 60 % of the adhesive’s maximum tensile strength (<span><math><msub><mi>S</mi><mrow><mi>max</mi></mrow></msub></math></span>) for durations of 12, 48, and 72 h. The aim was to assess how sustained creep affects the residual fracture properties of adhesive joints. Creep behavior was characterized by analyzing strain vs. time curves, identifying elastic, primary, and secondary creep stages. Results showed that joints tolerated 20–40 % of <span><math><msub><mi>S</mi><mrow><mi>max</mi></mrow></msub></math></span> for a maximum creep duration of 72 h. Subsequently, mode I fracture after creep (FAC) tests were performed on MDCB joints exposed to 20–40 % <span><math><msub><mi>S</mi><mrow><mi>max</mi></mrow></msub></math></span> at a crosshead speed of 0.5 mm/min. FAC tests revealed a significant reduction in fracture load and fracture energy with increasing creep stress levels and durations compared to control specimens without creep exposure. Fracture surface analysis indicated a transition from cohesive failure to a combination of adhesive and cohesive failure with longer creep durations. Finally, a semi-empirical model was developed using response surface methodology (RSM) to predict the residual mode I fracture energy of adhesive joints, enabling future numerical simulations of creep behavior.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104868"},"PeriodicalIF":5.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143375848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical characteristics and fracturing behavior of rock-concrete composite specimens with two pre-existing parallel flaws under uniaxial compression based on AE and DIC systems","authors":"Tengfei Guo ,&nbsp;Kewei Liu ,&nbsp;Houqiang Wang ,&nbsp;Xuefeng Si ,&nbsp;Yichao Rui ,&nbsp;Chengzhi Pu ,&nbsp;Yi Zhang ,&nbsp;Congxiang Yuan","doi":"10.1016/j.tafmec.2025.104866","DOIUrl":"10.1016/j.tafmec.2025.104866","url":null,"abstract":"<div><div>The crack propagation and coalescence behavior of rock-concrete composite structures with parallel double flaws is crucial for stability evaluation of rock-based concrete engineering projects. A uniaxial compression experiment was performed on rock-concrete composite (RCC) specimen in this study, and the crack extension process of RCC specimens was recorded with digital image correlation (DIC) equipment and acoustic emission (AE) equipment. The impacts of the inclination angles for flaws and rock-concrete interface planes on mechanical behavior and fracture process of RCC specimens were studied. The results reveal that fracture modes of specimens under compressive loading can be categorized into the following types: crack coalescing modes in different materials, crack extension modes in one material and crack extension modes in different materials. The initiation of cracks does not occur synchronously in different materials. Cracks in rock and concrete penetrate the interface and merge at low interface inclination angle, whereas interface cracks are generally formed at higher interface inclination angle, which inhibits crack coalescing in different materials. The coalescing of cracks between varying material is controlled by strength ratio. Increased concrete strength intensifies crack failure in rocks, facilitating crack penetration at the interface, while also strengthening the composite specimen and widening the peak strength differences across various flaw inclination angles. The peak strength is greatly affected by interface inclination angle. Furthermore, interface inclination angle and flaw inclination angle play an essential part in energy evolution. When interface inclination angle enlarges, the peak elastic strain energy first descends and subsequently ascends. The energy storage limit rises with enlarging the flaw inclination angle.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104866"},"PeriodicalIF":5.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Machine learning model to predict fracture of solder joints considering geometrical and environmental factors","authors":"Hossein Soroush,&nbsp;Amir Nourani,&nbsp;Gholamhossein Farrahi","doi":"10.1016/j.tafmec.2025.104865","DOIUrl":"10.1016/j.tafmec.2025.104865","url":null,"abstract":"<div><div>Predicting the fracture load and energy in solder joints is crucial for enhancing their reliability and preventing failure in electronic systems. This study introduced a novel framework by combining experimental data, machine learning (ML) models, and multi-objective optimization to predict and optimize the fracture behavior of solder joints. For this purpose, double cantilever beam (DCB) samples were fabricated and tested under displacement-control conditions and mode I crack propagation loading with a strain rate of 0.03 <span><math><mrow><msup><mrow><mi>s</mi></mrow><mrow><mo>-</mo><mn>1</mn></mrow></msup></mrow></math></span>, incorporating environmental factors (i.e., storage temperature and humidity) and geometrical constraints (i.e., adherend thickness, adherend width, and solder thickness). The one-way analysis of variance (ANOVA) test results revealed that while all studied factors affected the fracture load of the joints, only storage temperature, humidity, and adherend thickness meaningfully influenced the samples’ fracture energy. Next, using various machine learning (ML) techniques such as artificial neural network (ANN) and random forest (RF), the solder joint’s fracture load and energy were forecasted with 86 % and 80.5 % accuracy, respectively. According to the results, the ANN and RF models predicted the joint fracture load and energy more accurately than other ML algorithms. Finally, a multi-objective optimization was employed to achieve fracture load and energy optimal values in DCB specimens by implementing the NSGA-II algorithm. This integrated approach can minimize the need for experimental testing and enable accurate prediction of solder joint fracture behavior by employing various ML models and optimization algorithms considering different working conditions.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104865"},"PeriodicalIF":5.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143351384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on quasi-static mixed mode fracture in self-compacting concrete with longitudinal reinforcement and steel fibers","authors":"Ángel De La Rosa ,&nbsp;Gonzalo Ruiz ,&nbsp;Rodrigo Moreno","doi":"10.1016/j.tafmec.2024.104776","DOIUrl":"10.1016/j.tafmec.2024.104776","url":null,"abstract":"<div><div>This study investigates the mixed-mode fracture behavior of self-compacting concrete specimens reinforced with longitudinal steel bars and steel fibers. The experimental program involved three-point bending tests on asymmetrically notched prismatic specimens designed to induce and propagate mixed-mode cracks. The influence of different steel fiber dosages on crack initiation, propagation, and final failure was evaluated. Key findings reveal that the addition of steel fibers significantly enhances energy absorption and ductility under combined mode I and mode II fracture conditions. The results demonstrate the effectiveness of steel fibers in delaying brittle failure and improving the overall structural performance. Novelty lies in the combined use of self-compacting concrete and steel fibers to explore mixed-mode fracture mechanisms in reinforced elements.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"135 ","pages":"Article 104776"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A direct crack sizing approach from DIC strain analyses under elasto-plastic and dynamic conditions","authors":"Cheng Chen,&nbsp;Xudong Qian","doi":"10.1016/j.tafmec.2025.104861","DOIUrl":"10.1016/j.tafmec.2025.104861","url":null,"abstract":"<div><div>This paper proposes a novel approach to quantify the crack size from strain fields measured from digital image correlation (DIC), by extrapolating the positions at peak strain or peak strain increments identified along paths parallel to the crack plane. The proposed approach does not require data in the immediate vicinity of the crack tip, where DIC measurement is usually less accurate. This study utilizes the modified boundary layer model to demonstrate the strain pattern underpinning the crack size from HRR theory and the single edge notched bend model to verify the crack sizing accuracy from the strain fields. The experimental study further validates the proposed method in plane-sided and side-grooved specimens and evaluates the plastic wake effects on the crack-sizing accuracy for propagating cracks under elasto-plastic conditions. The proposed method identifies the crack tip location directly without measuring the elastic compliance, which enables fast and convenient crack sizing under challenging conditions such as the impact tests. This study demonstrates enhanced fracture resistance of the S550 material under increasing loading rates using the proposed crack sizing method.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"136 ","pages":"Article 104861"},"PeriodicalIF":5.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143197088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}