Engineering Fracture Mechanics最新文献

{"title":"Uncoupled ductile fracture initiation model for 5052 aluminum alloy with machine learning assisted identification of the material parameters","authors":"Yutao Li,&nbsp;Xuhui Sun,&nbsp;Xiang Hu,&nbsp;Yanhui Cheng,&nbsp;Fengmei Xue","doi":"10.1016/j.engfracmech.2025.111090","DOIUrl":"10.1016/j.engfracmech.2025.111090","url":null,"abstract":"<div><div>Ductile fracture is the predominant failure mode in plate forming; analyzing and predicting this fracture phenomenon is essential for enhancing the forming process and improving product quality. In this paper, the plastic model (modified Bai-Wierzbicki model) and the uncoupled ductile fracture criterion (Lou-Huh criterion) associated with two stress state parameters were used to construct an uncoupled model to predict the ductile fracture initiation of 5052 aluminum alloy, and a new method of machine learning assisted identification of the material parameters of the Lou-Huh criterion was proposed. This method overcame the difficulties of the traditional optimal fitting method, which requires a large amount of stress state information, and had a simple and easy operation procedure. The study results show that the uncoupled ductile fracture model can accurately predict the ductile fracture initiation of 5052 aluminum alloy, and the machine learning assisted calibration method can obtain more accurate material parameters than the optimal fitting method.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"320 ","pages":"Article 111090"},"PeriodicalIF":4.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738119","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":"Investigation on the instantaneous propagation behavior of mode I/II crack in Beishan granite under quasi-static loading","authors":"Dengke Zhang ,&nbsp;Hongsu Ma ,&nbsp;Zheng Zhou ,&nbsp;Shikun Pu ,&nbsp;Biao Wang ,&nbsp;Jianli Duan ,&nbsp;Erbing Li ,&nbsp;Liang Chen","doi":"10.1016/j.engfracmech.2025.111093","DOIUrl":"10.1016/j.engfracmech.2025.111093","url":null,"abstract":"<div><div>Brittle materials such as granite demonstrate significant rate and stress-state dependencies. Investigating the propagation of mode I/II crack in such materials under varying quasi-static loading conditions is crucial for valuating and predicting the stability of structural components. To this end, Beishan granite was selected as a case study and subjected to quasi-static loading rates to examine the varying propagation rates of failure cracks. By combining a self-designed mixed displacement–strain method and a direct current (DC) voltage fluctuation method, the temporal evolution of the fracture process zone (FPZ) and subcritical cracks under various loading conditions was obtained. Finally, the instantaneous propagation behavior of the failed main crack was revealed from a micro perspective. The results show that the main failure crack in granite evolves through three distinct stages: a crack latent stage, a steady-state propagation stage, and a high-speed crack propagation stage. During the latent stage, the accelerated failure crack propagation rate facilitates the early formation of the FPZ. During the steady-state propagation stage, the length of the FPZ increases rapidly, while subcritical cracks propagate along the crystal boundaries at relatively low instantaneous velocities, leading to a rougher fracture surface. During the high-speed propagation stage, the extremely high instantaneous velocity of the failed main crack allows it to penetrate directly through the high-strength quartz and feldspar crystals, producing a relatively smooth fracture surface. Furthermore, mode II loading produces a flatter fracture surface, longer FPZ, and subcritical cracks compared to mode I loading.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"320 ","pages":"Article 111093"},"PeriodicalIF":4.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143785926","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":"Effect of thermal–mechanical damage on deformation behaviours and fracture characteristics of sandstone under cyclic loading","authors":"Peng Yang ,&nbsp;Youliang Zhang ,&nbsp;Sheng Zeng ,&nbsp;Jie Cui ,&nbsp;Bing Sun","doi":"10.1016/j.engfracmech.2025.111091","DOIUrl":"10.1016/j.engfracmech.2025.111091","url":null,"abstract":"<div><div>Thermal and mechanical damage tests and uniaxial cyclic loading–unloading tests are conducted to investigate the effect of damage degree and temperature on the mechanical behaviour of sandstone under cyclic loading. The failure characteristics are analysed via acoustic emission (AE) monitoring and particle-flow code (PFC) simulations. The results indicate that the rock mass strength first increases and then decreases. The peak strain of samples increases with temperature, thus enhancing their ductility. The residual strain decreases gradually as the number of cycles increases. Additionally, the AE signal becomes more active with increasing temperature. The peak-frequency density ranges primarily between 100 and 200 kHz and shows a distinct discontinuity during cyclic loading. Shear failure predominantly occurs during the cyclic stage, whereas tensile failure is more common during the fracturing stage. The proportion of shear cracks increases with the damage degree. The simulation results show that stress reduction is typically accompanied by a rapid increase in the number of cracks. The failure process is dominated by tensile cracks, and the crack distribution angle is approximately 90°. AE events are concentrated near the sample boundary, and the frequency distribution is approximately normal as the magnitude changes. The change trend of the b-value is consistent with that of the peak strength.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"320 ","pages":"Article 111091"},"PeriodicalIF":4.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747563","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 data for damage mechanics simulation challenge","authors":"Liyang Jiang ,&nbsp;Laura J. Pyrak-Nolte ,&nbsp;Antonio Bobet ,&nbsp;Hongkyu Yoon","doi":"10.1016/j.engfracmech.2025.111065","DOIUrl":"10.1016/j.engfracmech.2025.111065","url":null,"abstract":"<div><div>While there are many computational approaches for simulating damage in rock and other materials, few have been ground truth tested with either known experimental data or with blind data sets. Here, we present a bench-mark laboratory data set for a damage mechanics challenge to compare computational approaches on damage evolution in brittle-ductile materials. The samples were fabricated through additive manufacturing to produce repeatable specimens designed to fail in controlled ways. The failure was induced in the samples using a 3-point bending test to produce different Modes such as Mode I and mixed Modes including I-II, I-III and I-II-III Modes to generate a calibration data set and a blind challenge data set. Data collected included spatial and temporal measurements from traditional digital load–displacement sensors, 2D digital image correlation measurement to map surface deformations, 3D X-ray microscopy to ground-truth the crack-failure geometry, and laser profilometry to capture surface roughness. The data sets are available, on a data repository, to the community to advance computational models to improve our ability to predict damage in brittle-ductile materials.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"320 ","pages":"Article 111065"},"PeriodicalIF":4.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143785927","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":"Mixed mode I/III fatigue behaviour of Polyetheretherketone","authors":"Florian J. Arbeiter ,&nbsp;Anja Gosch ,&nbsp;Tomáš Vojtek ,&nbsp;Gerald Pinter ,&nbsp;Pavel Hutař ,&nbsp;Michael Berer","doi":"10.1016/j.engfracmech.2025.111057","DOIUrl":"10.1016/j.engfracmech.2025.111057","url":null,"abstract":"<div><div>In this work, the fatigue behaviour of Polyetheretherketone (PEEK) under tensile (mode I) and out of plane shear (mode III) loading was examined by using razor blade notched cylindrical bars. By varying the applied mode I and mode III loadings, fatigue fracture curves of pure mode I and mixed mode I/III were established. The aim was to find a suitable method to describe the behaviour of both pure mode I and mixed mode I/III loading via a singular equivalent stress intensity factor. This was found possible by increasing the coefficient of the mode III contribution by more than 500 % compared to previous work on other thermoplastic materials. This significant change of the mode III contribution was mainly attributed to the different thermo-mechanical state of PEEK at the testing temperature of 23 °C, as well as the good friction properties of PEEK which leads to a transferal of mode III contributions to mode I contributions due to crack flank sliding of the formed factory roof formations on the fracture surfaces.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"320 ","pages":"Article 111057"},"PeriodicalIF":4.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738304","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":"Fracture pattern and failure mechanism of sandstone impacted by a high-pressure water jet under different stress loading states","authors":"Songqiang Xiao ,&nbsp;Juchong Xiao ,&nbsp;Qingyang Ren ,&nbsp;Renjun Feng ,&nbsp;Xin Meng ,&nbsp;Wentao Li ,&nbsp;Yugang Cheng ,&nbsp;Wenfeng Zhang ,&nbsp;Liang Zhang ,&nbsp;Junbo He","doi":"10.1016/j.engfracmech.2025.111068","DOIUrl":"10.1016/j.engfracmech.2025.111068","url":null,"abstract":"<div><div>High-pressure water jet technology is widely recognized as an efficient method for rock fragmentation in underground energy development and tunnel excavation engineering. The stress conditions of rock significantly influence the characteristics and efficiency of water jet breaking rock breakage. This study combines experimental and numerical simulation approaches to investigate the fracture patterns and failure mechanisms of rock subjected to water jet impact under various stress loading states. Through rock-breaking experiments, the effects of stress loading state, jet pressure, and rock lithology on the fragmentation characteristics and efficiency of sandstone were systematically examined. Utilizing a smoothed particle hydrodynamics-finite element method coupled algorithm, the evolution laws of damage and stress within the rock were quantitatively analyzed by introducing the comprehensive destructive-damage factor (<em>F_cdd</em>). Furthermore, the mechanisms underlying different fracture patterns and characteristics of sandstone fragmentation under varying stress loading states were elucidated. The results demonstrate that as stress loading increases, the threshold pressure for rock fragmentation rises, while rock-breaking efficiency decreases. Both rock-breaking depth and volume exhibit distinct trends with increasing jet pressure, following an S-shaped and exponential relationship, respectively. The unilateral stress loading is beneficial for the rock fragmentation and damage, with a more serious damage in stress loading direction, which is conducive to splitting fracture. Under the combined influence of jet impact and two-dimensional stress loading, the rock-breaking volume decreases, whereas the <em>F_cdd</em> value increases within a certain range. Three-dimensional stress loading significantly reduces the extent of rock fragmentation and damage, with both rock-breaking volume and <em>F_cdd</em> value decreasing exponentially as stress loading increases. Surface rock elements undergo instantaneous brittle failure, while deeper elements experience cumulative plastic damage. Stress loading has minimal impact on surface rock due to the extremely high water-hammer pressure but prolongs the initiation and accumulation of rock damage. Under water jet impact, the rock sequentially forms an erosion hole, fracture zone, plastic damage zone, elastic zone, and undamaged zone. Fragmentation and damage are more severe in the direction of greater stress loading, resulting in a larger fragmentation range. These findings could provide valuable insights for optimizing high-pressure water jet technology to efficiently break loaded rock in stress-endowed environments.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"320 ","pages":"Article 111068"},"PeriodicalIF":4.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725205","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":"Research on the damage and energy absorption characteristics of spiral gradient composite structures subjected to impact loading","authors":"Wei Chen ,&nbsp;Chong Chen ,&nbsp;Yiheng Zhang ,&nbsp;Hai Huang ,&nbsp;Xingxing Wu ,&nbsp;Xiaobin Li","doi":"10.1016/j.engfracmech.2025.111077","DOIUrl":"10.1016/j.engfracmech.2025.111077","url":null,"abstract":"<div><div>Inspired by the gradient structure and spiral structure in the dense impact region and the periodic region of the chelates of the finch-tail mantis shrimp, the back surface spiral laminates (BSL) and impact surface spiral laminates (ISL) with gradient design are designed and fabricated, and compared with compared with the common full spiral laminates (FSL) and non-spiral unidirectional laminates (NSL), respectively. The damage and energy absorption of four laminates with different structural designs are compared and analyzed by impact tests at two impact speeds. Combined with the numerical simulation analysis, the damage process and energy absorption of each layer are investigated, and the damage and energy absorption characteristics of the spiral gradient structure are discussed. The results indicate that the energy absorption of the FSL, ISL and BSL are 30.89 %, 27.13 % and 24.74 % greater than that of the NSL as the impact velocity is approximately 132 m/s. The spiral structure of laminated panels significantly improves impact resistance, although the influence of gradient structures remains to be determined. When the impact velocity is approximately 220 m/s, the energy absorption of the FSL, ISL and BSL are 33.21 %, 19.92 % and 19.96 % lower than that of the NSL, respectively. Compared to the gradient structure, the spiral structure in composite laminates significantly weakens the impact resistance.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"320 ","pages":"Article 111077"},"PeriodicalIF":4.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143767898","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 properties and fracture damage behavior of thermal storage rocks under constant amplitude low cycle fatigue loading","authors":"Jiangteng Li ,&nbsp;Zhanming Shi ,&nbsp;Fugui Yuan ,&nbsp;Baosheng Guo ,&nbsp;Mengxiang Wang ,&nbsp;Hang Lin ,&nbsp;Dongya Han ,&nbsp;Kaihui Li","doi":"10.1016/j.engfracmech.2025.111069","DOIUrl":"10.1016/j.engfracmech.2025.111069","url":null,"abstract":"<div><div>This paper studied the mechanical properties and fracture damage behavior of granite with thermal storage potential under constant amplitude low cycle fatigue loading. Based on the distribution evolution characteristics of acoustic emission (AE) ringing counts, b-values, and AF-RA, the crack growth process, crack growth scale, and the change in the ratio of tension-shear cracks in the samples were analyzed. Mineral scale evidence of thermal damage of the sample was given through mineral thin section analysis, and a fatigue damage model was established using the dissipated potential function. The results show that with the increase of the lower limit stress level, the fatigue deformation and fatigue damage of the sample increase in a step-like manner, while the loading and unloading response ratio and crack evolution process have staged evolution characteristics. Temperature has two mechanisms for the fatigue mechanical properties of the sample: strengthening and weakening. In the temperature strengthening stage, the fatigue strength of the sample increased by about 8% compared with the control group, showing a sudden instability failure mode dominated by tensile cracks. In the temperature weakening stage, the fatigue strength of the sample decreased by about 50%, and the failure mode changed to progressive instability failure. The mechanism of temperature influence is mainly controlled by factors such as thermal expansion of mineral particles, phase change, dehydration decomposition reaction, and evaporation of free water. Transgranular cracks, parallel cleavage, and stratification are mineral-scale evidence of thermal damage. The nonlinear relationship between fatigue damage and cycle number can be converted into a linear relationship between stage cumulative damage and stress ratio. The stage cumulative damage curve of the sample is inverted S shape, which can be divided into three stages: initial damage, stable damage, and accelerated damage.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"321 ","pages":"Article 111069"},"PeriodicalIF":4.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834564","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":"Fatigue behavior and nonlinear life prediction of open-hole thermoplastic composite laminates with drilling-induced delamination","authors":"Çağrı İlhan,&nbsp;Ulvi Şeker","doi":"10.1016/j.engfracmech.2025.111076","DOIUrl":"10.1016/j.engfracmech.2025.111076","url":null,"abstract":"<div><div>This research explores the fatigue behavior of thermoplastic composite laminates by focusing on the effects of drilling-induced delamination on fatigue performance. Fatigue tests were conducted on specimens with varying delamination factors and compared with unnotched specimens. Under static loading condition, the presence of open holes reduced the maximum strength by 45%, highlighting the detrimental impact of stress concentrations. Fatigue test results revealed distinct low cycle fatigue (LCF) and high cycle fatigue (HCF) regimes, with a transition from fiber-dominated failure to matrix-dominated failure as the number of cycles increased. The transition region varied with the delamination factor that occurring earlier for specimens with lower delamination. Nonlinear fatigue life prediction model was developed to integrate LCF and HCF behaviors into a single equation. The validated model that against experimental data achieved an error of less than 1.5%, demonstrating its robustness and accuracy in predicting fatigue performance. The use of thermoplastic composites, known for their recyclability and superior damage tolerance, underscores their potential for aerospace applications where lightweight and durable materials are critical. The findings of this study emphasize the importance of optimizing drilling parameters to minimize delamination and enhance fatigue performance of thermoplastic composites.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"320 ","pages":"Article 111076"},"PeriodicalIF":4.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747564","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":"Deep learning for interpreting elastic modulus and hardness from complex fractures","authors":"A. Sakhaee-Pour","doi":"10.1016/j.engfracmech.2025.111074","DOIUrl":"10.1016/j.engfracmech.2025.111074","url":null,"abstract":"<div><div>Indentation is a widely used measurement for determining the elastic modulus, based on tip penetration into a sample versus load, and is also employed to estimate hardness. This study proposes a new approach for estimating elastic modulus and hardness from the complex fractures of shale, a heterogeneous medium. A deep learning model was developed, fine-tuned through trial and error, and applied with the adaptive momentum solver to analyze 24,738 nanoindentation images—3,534 original and 21,204 augmented. The nanoindentations were obtained under loads ranging from 100 mN to 1,095 mN, yielding elastic modulus values from 14.0 GPa to 127.1 GPa and hardness values from 0.13 GPa to 5.60 GPa. The proposed method achieved mean squared errors (MSEs) of 3.7e-3 for normalized elastic modulus and 2.1e-3 for normalized hardness in independent measurements. These findings are significant, demonstrating that complex fracture patterns encode quantitative information about the elastic properties of the solid medium.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"320 ","pages":"Article 111074"},"PeriodicalIF":4.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143761069","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}