Theoretical and Applied Fracture Mechanics最新文献_第2页

Crack evolution in salt rock with a prefabricated flaw under uniaxial compression: Insights from coupled AE and DIC monitoring 含预制裂纹的盐岩单轴压缩裂纹演化：声发射与DIC耦合监测的启示

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2026-01-06 DOI: 10.1016/j.tafmec.2026.105449

Mingtian Zhang , Jinyang Fan , Mengying Luan , Jie Chen , Deyi Jiang , Yifan Wang , Dan Lu , Zongze Li , Daniel Nelias

Salt rock is widely recognized as an ideal host medium for underground energy storage and radioactive-waste disposal. Nevertheless, the presence of fractures within salt cavern gas storage can markedly compromise the integrity of the surrounding rock mass. Focusing on the mechanisms of fracture evolution and mechanical response in salt rock, this study conducted uniaxial compressive strength (UCS) tests on cubic salt specimens containing prefabricated flaws at various inclinations. Acoustic Emission (AE) monitoring and Digital Image Correlation (DIC) were integrated to capture the damage development and crack evolution in real time. The results show that: (1) Flaw inclination exerts a significant effect on both the UCS and the crack-propagation path of salt rock, exhibiting a clear and reproducible angle effect. (2) DIC effectively captures orientation-dependent crack trajectories, revealing the geometric complexity of surface crack evolution during failure. (3) According to the RA-AF criterion, the tensile-event fraction ranks 90° > 0° > 45° > 30° > 60°, consistent with the DIC observations and energy-index analysis. (4) The fractal dimension D increases over time, indicating progressive network densification and multiscale damage amplification. (5) The spatiotemporal distribution of AE events exhibits a damage-localization trend consistent with the evolution of the DIC principal strain field, confirming the complementary capabilities of the two monitoring techniques. The results provide a solid experimental basis for the quantitative evaluation of inclination effects and for the stability assessment of salt cavern storage, offering practical guidance for cavern design and long-term performance appraisal.

盐岩被广泛认为是地下能量储存和放射性废物处理的理想宿主介质。然而，盐穴储气库中裂缝的存在会明显损害围岩的完整性。针对盐岩断裂演化与力学响应机制，对不同倾角预制缺陷的立方盐试件进行了单轴抗压强度试验。将声发射（AE）监测和数字图像相关（DIC）技术相结合，实时捕捉损伤发展和裂纹演化过程。结果表明：(1)缺陷倾斜度对盐岩单轴载荷和裂纹扩展路径均有显著影响，且角度效应明显且可重现；(2) DIC有效捕获了与方向相关的裂纹轨迹，揭示了破坏过程中表面裂纹演化的几何复杂性。(3)根据RA-AF准则，拉伸事件分数为90°>； 0°> 45°> 30°> 60°，与DIC观测结果和能量指数分析一致。(4)分形维数D随时间增大，表明网络逐渐致密化，多尺度损伤放大。(5)声发射事件的时空分布表现出与DIC主应变场演化一致的损伤局部化趋势，证实了两种监测技术的互补性。研究结果为倾斜度定量评价和盐洞库稳定性评价提供了坚实的实验依据，为盐洞库设计和长期性能评价提供了实践指导。

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引用次数: 0

Peridynamic modeling of ballistic impact on metallic-ceramic functionally graded Sandwich plates 金属-陶瓷功能梯度夹层板弹道冲击的周动力学建模

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2026-01-02 DOI: 10.1016/j.tafmec.2026.105435

Ioannis Sioutis, Konstantinos Tserpes

Functionally Graded Sandwich Plates (FGSP) composed of metallic-ceramic layers have been widely investigated for their superior ballistic performance. Their through-the-thickness variation in material properties significantly enhances energy dissipation and resistance to projectile penetration. While traditional numerical FEA tools such as LS-Dyna can simulate such phenomena with reasonable accuracy, the non-local method of peridynamics (PD) offers a promising alternative for capturing complex fracture and failure mechanisms, particularly under dynamic loading. To the authors' best knowledge, direct comparison of the two methods in computational terms on an actual case study has been lacking from literature. In the present article, the ballistic impact of a 0.30 caliber steel projectile to a 7-layer Al-SiC composite FGSP is numerically examined using a bond-based PD framework. Although LS-Dyna was initially selected for both FEA and PD simulations, limitations of the available PD implementation necessitated the adaptation of LAMMPS molecular dynamics simulator to accommodate a fully customized bond-based PD model. A comprehensive parametric study was performed, including variations in lattice discretization, horizon radius and material inhomogeneity, to assess the accuracy and robustness of the PD approach. Comparative analysis against conventional FEA results is presented, highlighting the strengths and limitations of each method in predicting impact response, failure modes and damage evolution. The results demonstrate that the PD method provides enhanced resolution of fracture phenomena, offering valuable insights into the design of advanced FGSPs in ballistic protection applications.

由金属陶瓷层组成的功能梯度夹层板（FGSP）因其优异的弹道性能而受到广泛的研究。它们的材料性能随厚度的变化显著提高了能量耗散和抗弹丸侵彻能力。传统的数值有限元分析工具，如LS-Dyna，可以以合理的精度模拟这种现象，而非局部周动力学（PD）方法为捕获复杂的断裂和破坏机制，特别是在动态载荷下，提供了一种有希望的替代方法。据作者所知，文献中缺乏对这两种方法在计算方面的实际案例研究的直接比较。在本文中，使用基于键合的PD框架对0.30口径钢弹丸对7层Al-SiC复合材料FGSP的弹道冲击进行了数值研究。虽然LS-Dyna最初被选择用于FEA和PD模拟，但现有PD实现的局限性使得LAMMPS分子动力学模拟器必须适应完全定制的基于键的PD模型。进行了全面的参数研究，包括晶格离散化，水平半径和材料不均匀性的变化，以评估PD方法的准确性和鲁棒性。通过与传统有限元分析结果的对比分析，突出了每种方法在预测冲击响应、破坏模式和损伤演化方面的优势和局限性。结果表明，PD方法提高了断裂现象的分辨率，为弹道防护应用中先进FGSPs的设计提供了有价值的见解。

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引用次数: 0

Mixed-mode(I/II) fracture behaviour and criterion-based analysis of banana fiber reinforced epoxy composites using asymmetric SCB specimens 香蕉纤维增强环氧复合材料的I/II混合模式断裂行为及基于准则的非对称SCB试样分析

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2026-01-02 DOI: 10.1016/j.tafmec.2025.105433

L.C. Shashidhar , Saravanabavan , Rajeev Kumar Gupta , S.C. Ramesh Kumar , R. Vara Prasad Kaviti , M.A. Umarfarooq , Vinayak S. Uppin , B.H. Maruthi Prashanth

This work investigates the mixed-mode (I/II) fracture behaviour of banana fiber-reinforced epoxy composite using asymmetric semi-circular bend (ASCB) specimens. Laminates were fabricated via hand layup-assisted vacuum bag moulding, with banana fibers integrated into an epoxy matrix. Three-point bending tests were conducted on ASCB specimens (radius 60 mm, thickness 6 mm, and notch length 30 mm) under varying asymmetric support spans (40–40 mm to 40–20 mm) to transition from pure mode I to mixed-mode I/II loading. Results showed a non-monotonic mode I fracture toughness (K_I) trend (1.70 MPa.m^1/2 decreasing to 1.54 MPa.m^1/2, then increasing to 1.92 MPa.m^1/2) and rising mode II fracture toughness (K_II) (0.30 to 0.87 MPa.m^1/2) with increasing mode II contribution, attributed to fiber-matrix interactions.

Experimental results were compared with analytical predictions based on the Power Law, maximum tangential stress (MTS), generalised maximum tangential stress (GMTS), and maximum energy release rate (Gmax) criteria. The Power Law criterion underestimated fracture resistance failing to capture constraint effects and fiber-related toughening. Incorporation of T-stress in the MTS and GMTS models improved predictions, though both overestimated crack initiation angles. Among the compared criteria, Gmax provided the closest correlation with crack initiation angles (0° to −17.26°), highlighting its suitability for natural fiber composites. Overall, the findings reveal a strong dependence of mixed-mode fracture behaviour on fiber-matrix interaction mechanisms, confirming the suitability of energy-based criteria for accurately modelling the fracture response of anisotropic natural fiber composites.

本文采用非对称半圆弯曲（ASCB）试样研究了香蕉纤维增强环氧复合材料的混合模式（I/II）断裂行为。层压板是通过手工分层辅助真空袋成型制造的，香蕉纤维集成到环氧树脂基体中。对ASCB试件（半径60 mm，厚度6 mm，缺口长度30 mm）在不同的非对称支承跨度（40-40 mm ~ 40-20 mm）下进行了由纯I型加载过渡到混合I/II型加载的三点弯曲试验。结果表明，断裂韧性呈非单调I型（1.70 MPa）趋势。m1/2减小到1.54 MPa。m1/2，然后增加到1.92 MPa。m1/2)， II型断裂韧性（KII）上升（0.30 ~ 0.87 MPa）。m1/2)，模式II贡献增加，归因于纤维-基质相互作用。实验结果与基于幂律、最大切向应力（MTS）、广义最大切向应力（GMTS）和最大能量释放率（Gmax）准则的分析预测结果进行了比较。幂律准则低估了断裂抗力，未能捕捉到约束效应和纤维相关的增韧。在MTS和GMTS模型中加入t应力改进了预测，尽管两者都高估了裂纹起裂角。其中，Gmax与裂纹起裂角（0°~ - 17.26°）的相关性最密切，突出了其对天然纤维复合材料的适用性。总的来说，研究结果揭示了混合模式断裂行为对纤维-基质相互作用机制的强烈依赖，证实了基于能量的标准准确模拟各向异性天然纤维复合材料断裂响应的适用性。

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引用次数: 0

Failure modes and energy evolution of jointed rock mass with holes under high temperature and fatigue loading 高温疲劳载荷下节理岩体孔洞破坏模式及能量演化

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2026-01-02 DOI: 10.1016/j.tafmec.2025.105434

Piaopiao Tan , Fenghua Nie, Zeyue Wang , Yi Tang , Hang Lin

Deep-buried tunnel construction is greatly influenced by high ground stress, temperature, and inevitable joint defects in the surrounding geology. This study investigates the effects of high temperature on the mechanical behavior and failure characteristics of red sandstone with combined far-field joints and horseshoe-shaped holes, simulating deep-buried tunnel conditions. Samples were heat-treated at various high temperature ranges and subjected to uniaxial compression and cyclic loading tests, with simultaneous acoustic emission (AE) and digital image correlation (DIC) monitoring. Results show that peak stress and fatigue failure stress increase then decrease with temperature, peaking at 600 °C, while elastic modulus sharply declines above this temperature. Thermal damage promotes microcrack development and alters deformation stages, increasing compaction and residual strain during fatigue loading, but does not significantly change failure modes. However, thermal damage had little effect on the failure mode of the specimens. The penetration of the rectangular side rock bridge of the hole precedes that of the circular side rock bridge, and both penetrations are located at the arch waist of the hole. Failure is dominated by shear cracks extending from joint tips, guided by far-field joints. Analyzing the energy evolution under fatigue loading, a novel quadratic model is proposed to predict the elastic energy density at failure, outperforming traditional linear models, especially under complex loading cycles. This study offers new insights into the damage evolution of rock masses under high ground stress and temperature conditions, contributing to the improved design and safety of deep-buried tunnel construction.

深埋隧道施工受高地应力、高温度和周围地质中不可避免的节理缺陷的影响较大。模拟深埋隧道条件，研究了高温对远场节理与马蹄形孔洞组合红砂岩力学行为及破坏特征的影响。在不同的高温范围内对样品进行热处理，并进行单轴压缩和循环加载试验，同时进行声发射（AE）和数字图像相关（DIC）监测。结果表明，峰值应力和疲劳破坏应力随温度的升高先增大后减小，在600℃达到峰值，而弹性模量在600℃以上急剧下降。热损伤促进微裂纹发展，改变变形阶段，增加疲劳加载过程中的压实和残余应变，但不显著改变破坏模式。热损伤对试件的破坏模式影响不大。孔内矩形侧岩桥的贯通先于圆形侧岩桥，且均位于孔拱腰处。破坏主要是由远场节理引导的从节理尖端延伸的剪切裂纹。分析了疲劳载荷下的能量演化，提出了一种新的二次模型来预测失效时的弹性能量密度，优于传统的线性模型，特别是在复杂载荷循环下。该研究为高地应力和高温度条件下岩体的损伤演化提供了新的认识，有助于改进深埋隧道施工的设计和安全性。

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引用次数: 0

Fracture characteristics and energy catastrophe properties of sandstone with the circular hole: The influence of different inclusions 含圆孔砂岩断裂特征及能量突变特性：不同包裹体的影响

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-31 DOI: 10.1016/j.tafmec.2025.105430

Kai Zhang , Guowei Ma , Ke Zhang

Holes, as the common defects in rock masses, are often accompanied by natural or artificial inclusions, which further complicate the failure mechanisms. To study the fracture mechanisms of sandstone with the circular hole under various filling conditions, uniaxial compression tests are conducted on three types of specimens. Combined with digital image correlation (DIC) and energy evolution theory, the mechanical degradation, crack propagation, spatial and temporal non-uniformity of deformation, and energy catastrophe characteristics are analyzed. The results show that the presence of the hole significantly degrades the mechanical properties of sandstone, with the uniaxial compressive strength (UCS) and elastic modulus (E) reduced by approximately 34.08 % and 21.03 %, respectively, compared with intact specimens. Inclusion filling partially restores the mechanical performance: soft inclusion increases the UCS and E by about 8.50 % and 14.17 %, whereas hard inclusion leads to more pronounced improvements of approximately 12.48 % and 19.87 %, respectively. The crack evolution patterns vary considerably with the filling condition: unfilled specimen experience tensile crack initiation followed by tensile-shear transition leading to shear-dominated failure; soft inclusions delay crack propagation and promote interface-controlled ductile failure; hard inclusions accumulate internal cracks, resulting in more abrupt and brittle instability. The proposed spatial and temporal non-uniformity indicators (I_S and I_T), derived from DIC data, effectively characterize the evolution of strain localization and identify the transition from stable fracture to unstable fracture. Moreover, the developed grey cusp catastrophe model based on elastic and dissipated strain energy density evolutions successfully captures abrupt changes in energy evolution, providing reliable physical interpretation and validation for the instability trends revealed by I_S and I_T.

孔洞作为岩体中常见的缺陷，常伴有天然或人工包裹体，使其破坏机制更加复杂。为研究不同充填条件下圆孔砂岩的破裂机理，对三种试件进行了单轴压缩试验。结合数字图像相关（DIC）和能量演化理论，分析了材料的力学退化、裂纹扩展、变形时空不均匀性和能量突变特征。结果表明，孔洞的存在显著降低了砂岩的力学性能，单轴抗压强度（UCS）和弹性模量(E)分别比完整试件降低了约34.08%和21.03%。包裹体填充部分恢复了合金的力学性能：软包裹体的UCS和E分别提高了8.50%和14.17%，而硬包裹体的UCS和E分别提高了12.48%和19.87%。不同充填条件下，裂隙演化模式差异较大：未充填试样先经历拉伸裂纹萌生，然后经历拉剪转变，最终形成剪切为主破坏；软夹杂物延缓裂纹扩展，促进界面可控延性破坏；硬夹杂物在裂纹内部堆积，导致脆性脆性失稳。本文提出的时空非均匀性指标（IS和IT）来源于DIC数据，可以有效表征应变局部化的演化过程，识别从稳定骨折到不稳定骨折的转变。此外，建立的基于弹性和耗散应变能密度演化的灰尖突变模型成功捕获了能量演化的突变，为IS和IT揭示的不稳定趋势提供了可靠的物理解释和验证。

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引用次数: 0

Assessing fracture characteristics of high-performance fiber-reinforced concrete using notched flexural specimens 用缺口弯曲试件评估高性能纤维增强混凝土的断裂特性

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-31 DOI: 10.1016/j.tafmec.2025.105427

Duy-Liem Nguyen , Tan-Khoa Nguyen , Kha-Ky Lam , Duc-Kien Thai , Ngoc-Thanh Tran

The fracture characteristics of high-performance fiber-reinforced concrete (HPFRC) using notched flexural specimens were assessed under both static and repeated loads. There were three HPFRC mixtures examined: HPFRC0 (without fibers), HPFRC1 (containing 1.0 vol% hooked and 0.5 vol% smooth steel fibers), and HPFRC2 (with 0.5 vol% hooked and 1.0 vol% short steel fibers). All test specimens were rectangular prisms measuring 40 × 40 × 160 mm³. Four notch depths, including 0, 5, 10, and 15 mm, were applied to each mix design. All flexural specimens were rectangular prisms with dimensions of 40 × 40 × 160 mm³. The specimens were evaluated under a three-point bending (3 PB) configuration with a span length of 120 mm. The results indicate that the hardening fracture energy of all HPFRCs decreased with notch depth under static flexural loading. The total fracture energy and length of cohesive zone were greatest at a notch depth of 0 mm for HPFRC0, and at a notch depth of 10 mm for both HPFRC1 and HPFRC2. When subjected to repeated loading, specimens with a 5-mm notch exhibited the highest fatigue energy per cycle across all HPFRC types. Additionally, at a constant fatigue energy per cycle, increasing the notch depth led to a longer fatigue life.

采用缺口抗弯试件对高性能纤维混凝土（HPFRC）在静载荷和重复载荷作用下的断裂特性进行了研究。研究了三种HPFRC混合物：HPFRC0（不含纤维）、HPFRC1（含1.0卷%钩状钢纤维和0.5卷%光滑钢纤维）和HPFRC2（含0.5卷%钩状钢纤维和1.0卷%短钢纤维）。所有试件均为矩形棱镜，尺寸为40 × 40 × 160 mm3。每种混合设计采用4种缺口深度，包括0、5、10和15 mm。所有试件均为矩形棱镜，尺寸为40 × 40 × 160 mm3。试件在跨度为120 mm的三点弯曲（3pb）配置下进行了评估。结果表明：在静态弯曲载荷作用下，所有HPFRCs的硬化断裂能随缺口深度的增加而减小；缺口深度为0 mm时，HPFRC0的总断裂能和黏结区长度最大，缺口深度为10 mm时，HPFRC1和HPFRC2的断裂能和黏结区长度最大。当重复加载时，在所有HPFRC类型中，具有5mm缺口的试件每循环表现出最高的疲劳能量。此外，在一定的循环疲劳能量下，增加缺口深度可以延长疲劳寿命。

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引用次数: 0

Enhancing interlaminar fracture toughness of carbon fiber/epoxy resin composite by interleaving polyvinylidene fluoride electrospun beaded fiber membranes 聚偏氟乙烯静电纺丝珠状纤维膜交织增强碳纤维/环氧树脂复合材料的层间断裂韧性

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-30 DOI: 10.1016/j.tafmec.2025.105432

Fei Wang , Chuanguo Ma , Liaoxian Wei , Yuqi Liu , Shaoning Lu

Electrospun nanofiber membranes are promising interlayer toughening materials for carbon fiber/epoxy (CF/EP) composites. However, the simple control of their morphology to achieve a significant interlaminar toughening effect remains a relatively underexplored area. Herein, polyvinylidene fluoride (PVDF) electrospun membranes were successfully prepared through solvent regulation of N, N-dimethylformamide/acetone (DMF/ACE) ratios. Controlled morphological evolution was accomplished through the systematic increase of the DMF fraction from 0.6 to 1.0. Smooth large-diameter fibers underwent a transition to bead-on-string architectures, with the bead density increasing gradually and the fiber diameter decreasing. This trend reached its peak at a DMF:ACE ratio of 9:1. This optimized structure enhanced the mode I fracture toughness of CF/EP laminates to 1.08 ± 0.04 kJ·m⁻², representing 116 % improvements over unmodified laminates. Crack deflection by beads, interfacial bead pull-out, and constrained fiber bridging were identified as dominant toughening mechanisms. Cohesive zone modeling simulations further validated a 74.7 % interfacial strength enhancement without stiffness compromise. This solvent-regulation strategy provides a new perspective on the application of electrospun fiber membranes in the interlaminar toughening of CF/EP composites.

静电纺丝纳米纤维膜是碳纤维/环氧树脂（CF/EP）复合材料中很有前途的层间增韧材料。然而，简单地控制它们的形态以达到显著的层间增韧效果仍然是一个相对欠发达的领域。通过溶剂调节N， N-二甲基甲酰胺/丙酮（DMF/ACE）的比例，成功制备了聚偏氟乙烯（PVDF）静电纺丝膜。通过系统地将DMF分数从0.6增加到1.0，实现了受控的形态进化。光滑大直径光纤由珠串结构过渡到珠串结构，珠密度逐渐增大，纤维直径逐渐减小。这一趋势在DMF:ACE比率为9:1时达到顶峰。优化后的结构使CF/EP层压板的I型断裂韧性提高到1.08±0.04 kJ·m−2，比未改性的层压板提高了116%。裂纹挠曲由珠，界面珠拉出，和约束纤维桥接被确定为主要的增韧机制。内聚区模拟进一步验证了在不降低刚度的情况下界面强度提高74.7%。这种溶剂调节策略为静电纺丝纤维膜在CF/EP复合材料层间增韧中的应用提供了新的前景。

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引用次数: 0

Numerical modeling of three-dimensional quasi-brittle fracture and machining-induced damage in orthotropic composites 正交异性复合材料三维准脆性断裂及加工损伤的数值模拟

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-30 DOI: 10.1016/j.tafmec.2025.105415

Pawan Kumar , Anil Meena , Shantanu S. Mulay

This study examines three-dimensional (3D) orthogonal machining-induced fracture in carbon/epoxy composites using a continuum damage mechanics (CDM) model. The model, based on Hashin’s 3D failure theory with a linear softening law, is implemented as VUMAT subroutine in the explicit ABAQUS® framework to capture failure initiation and damage evolution. Validation against numerical benchmarks and experimental data — through lamina patch tests and predicted crack paths in both lamina and laminates — demonstrate the model robustness. It successfully reproduces crack nucleation, branching, arrest, and intra/interlaminar failures typical of composite fracture. Orthogonal machining simulations are conducted for lamina with varying fiber orientations and for laminates of different layups. Localized 3D stress analysis near the tool tip revealed the mechanisms driving subsurface fracture and 3D chip formation. In 0° plies, fracture is dominated by fiber compression and matrix crushing under longitudinal compression and in-plane shear, with minimal subsurface damage. At 45° and 90°, shearing and fiber–matrix debonding prevail under combined shear and transverse stresses, while 135° ply exhibits the most severe subsurface damage due to fiber bending and interfacial debonding. For laminates (symmetric, antisymmetric, unsymmetric, and cross-ply), fracture patterns are strongly orientation-dependent. Plies at 45°, 60°, and

- 120 °

promote the chip flow along the fiber directions, while the plies at

- 45 °

and 120° fracture perpendicular to the fibers due to fiber–rake interactions. Subsurface damage depends on the ply location, with the outer 45° and 60° plies showing the highest susceptibility. However, cross-ply laminates exhibit the least damage owing to favorable stress redistribution. This study thus successfully reveals the mechanics of 3D crack propagation in composites subjected to orthogonal machining that can also be extended to other loadings.

本研究使用连续损伤力学（CDM）模型研究了碳/环氧复合材料的三维（3D）正交加工诱导断裂。该模型基于Hashin的三维失效理论，具有线性软化定律，在显式ABAQUS®框架中作为VUMAT子程序实现，以捕获失效起始和损伤演化。对数值基准和实验数据的验证-通过层板贴片测试和预测层板和层板的裂纹路径-证明了模型的鲁棒性。它成功地再现了复合断裂典型的裂纹成核、分支、止裂和层内/层间破坏。对不同纤维取向的层板和不同铺层的层板进行了正交加工仿真。工具尖端附近的局部三维应力分析揭示了驱动地下断裂和三维切屑形成的机制。在0°层段，纵向压缩和面内剪切作用下，断裂以纤维压缩和基质破碎为主，次表面损伤最小。在45°和90°处，剪切和纤维-基体脱粘在剪切和横向复合应力下普遍存在，而135°处由于纤维弯曲和界面脱粘而表现出最严重的亚表面损伤。对于层压板（对称、反对称、不对称和交叉铺层），断裂模式强烈依赖于方向。45°、60°和- 120°的层叠层促进了切屑沿纤维方向流动，而- 45°和120°的层叠层由于纤维-耙的相互作用而垂直于纤维断裂。亚表面损伤取决于层的位置，外部45°和60°层表现出最高的敏感性。然而，由于有利的应力重新分布，交叉层合板表现出最小的损伤。因此，该研究成功地揭示了正交加工复合材料中三维裂纹扩展的力学，也可以扩展到其他载荷。

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引用次数: 0

A localizing gradient damage model for hydrogen-assisted cracking 氢辅助开裂的局部梯度损伤模型

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-29 DOI: 10.1016/j.tafmec.2025.105426

Alok Negi , Imad Barsoum

Hydrogen-assisted cracking remains a critical threat to the durability and safety of metallic structures, arising from the interaction of diffusible hydrogen with the microstructure, which weakens interatomic cohesion and promotes premature fracture. This work presents a novel chemo-mechanical modeling framework that integrates material deformation, stress-assisted hydrogen diffusion, and hydrogen-induced degradation of mechanical properties. A localizing gradient damage enhancement is employed to regularize softening responses and produce sharply localized damage zones that correspond to macroscopic cracks, thereby eliminating the spurious effects typically observed in conventional gradient damage models. The approach delivers physically consistent, mesh-objective crack propagation and seamless integration into standard finite element workflows without requiring predefined crack paths or cohesive interfaces. The framework is implemented using a staggered solution strategy to ensure stable convergence even in nonlinear regimes and is validated through three representative case studies: a cracked plate under hydrogen charging, compact tension testing subjected to internal hydrogen-assisted cracking, and single-edge notch tension tests in sour environments. The simulations reproduce key experimental trends and accurately capture the interplay among hydrogen transport, stress fields, and damage localization. Owing to its predictive capability, numerical robustness, and ease of implementation, the proposed method provides a practical computational tool for assessing hydrogen-induced fracture and structural integrity in hydrogen-rich environments.

氢辅助开裂是金属结构耐久性和安全性的重要威胁，它是由扩散氢与微观结构相互作用引起的，它削弱了原子间的凝聚力，促进了金属结构的过早断裂。这项工作提出了一种新的化学-力学建模框架，该框架集成了材料变形，应力辅助氢扩散和氢诱导的机械性能退化。采用局部梯度损伤增强来规范软化响应，并产生与宏观裂纹对应的急剧局部化损伤区域，从而消除了传统梯度损伤模型中常见的虚假效应。该方法提供了物理上一致的网格目标裂纹扩展，并无缝集成到标准有限元工作流程中，而不需要预定义的裂纹路径或内聚接口。该框架采用交错解决策略来实现，以确保即使在非线性情况下也能稳定收敛，并通过三个代表性案例研究进行了验证：充氢下的裂纹板、内部氢辅助开裂的致密张力测试，以及酸性环境下的单刃缺口张力测试。模拟重现了关键的实验趋势，并准确地捕捉了氢输运、应力场和损伤局部化之间的相互作用。该方法具有预测能力强、数值鲁棒性好、易于实现等优点，为富氢环境中氢致裂缝和结构完整性评估提供了实用的计算工具。

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引用次数: 0

Experimental and numerical analysis of temperature and cooling medium on the mode-I fracture behavior of granite 温度和冷却介质对花岗岩i型断裂行为的实验与数值分析

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-29 DOI: 10.1016/j.tafmec.2025.105431

Xiang Wang , Zhende Zhu , Yingjie Chen , Shu Zhu , Xiangcheng Que , Chong Shi , Semaierjiang Maimaitiyusupu

The fracture properties of rock are critical in controlling the propagation of fracture networks in Enhanced Geothermal Systems (EGS). This study aims to investigate the mechanisms by which different temperatures (150 °C, 300 °C, 450 °C, 600 °C) and cooling methods (natural cooling, water cooling, liquid nitrogen cooling) influence the fracture toughness and crack propagation behavior of granite. Through a combination of split tests on Brazilian disc specimens with pre-existing flaws and numerical simulation, the following key conclusions are drawn: (1) The heat treatment temperature is the dominant factor causing the degradation of the mode-I fracture toughness (K_IC) of granite. After treatment at 600 °C, the K_IC of specimens cooled by liquid nitrogen dropped to approximately 0.69 MPa·m¹/², representing a maximum degradation of 49 % compared to the value at room temperature (1.35 MPa·m¹/²). (2) At a given temperature, the cooling rate acts as a “damage amplifier”. At 600 °C, the K_IC of water-cooled and liquid nitrogen-cooled specimens was further reduced by approximately 19 % and 16 %, respectively, compared to naturally cooled specimens. (3) Numerical simulations reveal the degradation mechanism from the perspective of pre-damage to the crack driving force: the intense thermal tensile stress generated at the crack tip during rapid cooling is equivalent to a pre-load on the crack. (4) The crack path transitions from straight and stable propagation under low temperatures/natural cooling to unstable deflection and branching under high temperatures/rapid cooling. This study quantitatively elucidates the origin of thermal damage from a fracture mechanics perspective, providing theoretical support for the optimization of thermal fracturing technologies.

在增强型地热系统（EGS）中，岩石的裂缝性质是控制裂缝网络扩展的关键。本研究旨在探讨不同温度（150°C、300°C、450°C、600°C）和冷却方式（自然冷却、水冷却、液氮冷却）对花岗岩断裂韧性和裂纹扩展行为的影响机制。通过对存在缺陷的巴西盘试件进行劈裂试验与数值模拟相结合，得出以下重要结论：(1)热处理温度是导致花岗岩i型断裂韧性（KIC）退化的主导因素。600℃时，液氮冷却试样的KIC降至0.69 MPa·m1/2左右，与室温（1.35 MPa·m1/2）相比，最大降解率为49%。(2)在一定温度下，冷却速率起着“损伤放大器”的作用。在600℃时，水冷和液氮冷却试样的KIC分别比自然冷却试样降低了约19%和16%。(3)数值模拟从预损伤的角度揭示了裂纹驱动力的退化机制：快速冷却过程中裂纹尖端产生的强烈热拉应力相当于裂纹上的预载荷。(4)裂纹路径由低温/自然冷却下的直线稳定扩展向高温/快速冷却下的不稳定挠曲和分支扩展转变。本研究从裂缝力学角度定量阐明了热损伤的成因，为热压裂技术的优化提供了理论支持。

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引用次数: 0