Theoretical and Applied Fracture Mechanics最新文献_第4页

Characterization of mixed-mode I/II translaminar fracture in carbon fibre laminates under biaxial loading 双轴载荷下碳纤维层合板I/II混合模式跨层断裂表征

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-20 DOI: 10.1016/j.tafmec.2025.105419

Yajing Feng , Chang Lei , Jinheng Shi , Youcun Zhao , Ting Zhang , Hao cui

This study investigates the fracture initiation behavior of carbon fibre-reinforced composite laminates under mixed-mode I/II biaxial loading using cruciform specimens with centrally inclined cracks. The combined effects of biaxial load ratio and crack angle were examined by systematically varying both parameters. The fracture energy at crack initiation was quantified using a J-integral–based method coupled with digital image correlation (DIC), and decomposed into Mode I (

J_{1}

) and Mode II (

J_{2}

) components through an energy-based mode partitioning approach. Complementary post-fracture surface analysis and infrared thermography provided further insights into energy dissipation and failure mechanisms. The results reveal that both the total fracture energy (

J_{total}

) and the shear contribution (

J_{2}

) increase with crack angle and biaxial load ratio, indicating a progressive transition from opening- to shear-dominated fracture initiation. The thermographic and morphological observations corroborate the energy decomposition, confirming a strong correspondence between mode mixity evolution and local energy release processes. Based on these findings, a unified fracture energy criterion incorporating explicit dependence on crack angle and load ratio was established. The proposed criterion offers a physically grounded and experimentally supported framework for characterizing mixed-mode fracture initiation in composite laminates under complex multiaxial loading conditions.

采用中心倾斜裂纹的十字形试样，研究了碳纤维增强复合材料层合板在I/II混合模式双轴加载下的起裂行为。通过系统地改变双轴载荷比和裂纹角，考察了两者的联合效应。采用基于j积分的方法结合数字图像相关（DIC）对裂纹起裂时的断裂能进行量化，并通过基于能量的模态划分方法将断裂能分解为I型（J1）和II型（J2）分量。压裂后的附加表面分析和红外热成像为进一步了解能量耗散和破坏机制提供了帮助。结果表明：总断裂能（Jtotal）和剪切贡献（J2）均随着裂纹角度和双轴载荷比的增大而增大，表明断裂起裂方式由开口主导向剪切主导逐步转变；热成像和形态观测证实了能量分解，证实了模态混合演化与局部能量释放过程之间的强烈对应关系。在此基础上，建立了统一的断裂能准则，该准则与裂纹角和载荷比有显式关系。该准则为复杂多轴加载条件下复合材料层合板的混合模式起裂提供了物理基础和实验支持框架。

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引用次数: 0

Design method and numerical study for determining ceramic fracture parameters based on mesoscopic grains 基于介观晶粒确定陶瓷断裂参数的设计方法及数值研究

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-20 DOI: 10.1016/j.tafmec.2025.105402

Min Zhang , Yongchang Xie , Junfeng Guan , Chaopeng Xie , Ruicong Han , Lielie Li , Sheng Jia

In this paper, a design method for simultaneously determining the tensile strength and fracture toughness of ceramic materials, i.e., the two-point method, is proposed by considering the mesoscopic grain effects and introducing the geometric structural parameter (a_e) ratio based on the boundary effect fracture model. The statistical analysis of the test data acquired on three-point bending specimens of ceramic materials with five different relative sizes was carried out. The logarithmic formula for the fictitious crack growth length of the ceramics was determined. When the relative size (W-a₀)/d_av is less than 150, nonlinear elastic fracture occurs; otherwise, linear elastic fracture appears. The two-point method was not limited by the loading form and specimen size, demonstrating simplicity and accuracy in the results. Meanwhile, the full curve of ceramic material damage was accurately plotted, and the peak load was predicted using the parameters determined via the above two-point method. The mesoscopic numerical analysis also revealed that an a_e ratio above 2 is necessary for determining fracture parameters through the two-point method.

本文基于边界效应断裂模型，在考虑细观晶粒效应的基础上，引入几何结构参数（ae）比，提出了一种同时确定陶瓷材料抗拉强度和断裂韧性的设计方法——两点法。对5种不同相对尺寸的陶瓷材料三点弯曲试样的试验数据进行了统计分析。确定了陶瓷虚拟裂纹扩展长度的对数公式。当相对尺寸(W-a0)/ day小于150时，发生非线性弹性断裂；否则，出现线弹性断裂。两点法不受加载形式和试样尺寸的限制，结果简单、准确。同时，准确绘制了陶瓷材料损伤的全曲线，并利用上述两点法确定的参数对峰值载荷进行了预测。细观数值分析也表明，两点法确定断裂参数时，ae比必须大于2。

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引用次数: 0

Fatigue damage mechanism and crack evolution law of central-boundary fractured sandstone under cyclic loading 循环荷载作用下中心边界断裂砂岩疲劳损伤机理及裂纹演化规律

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-19 DOI: 10.1016/j.tafmec.2025.105416

Penghui Deng , Zhijun Zhang , Yakun Tian , Lingling Wu , Min Wang , Zheng Yang , Kaiwen Tong , Lin Hu

In the process of mineral resource development, intense excavation-induced disturbances coupled with heterogeneous fissured rock masses pose formidable challenges to mining engineering. In this study, the cyclic loading tests with different maximum cyclic loads were carried out on central-boundary fractured and intact sandstones, combining with the monitoring techniques such as acoustic emission (AE) and digital imaging correlation (DIC). The fatigue damage mechanism and crack evolution law of sandstones under different maximum cyclic loads were comprehensively analysed. The results show that under cyclic loading, the presence of fractures significantly reduces the peak strength of the rock and changes the damage mode. The fatigue deformation, strength, fatigue life, dynamic elastic modulus and damping ratio of the rock are all affected by the maximum cyclic load. The maximum cyclic load can cause “cyclic strengthening effect” and “cyclic weakening effect” on sandstone. Based on the AE parameters, we found that the b-values and energy counts of the samples fluctuated when approaching fatigue failure. Under cyclic loading, the samples exhibited tensile -dominated mixed failure. Fractured sandstone will develop secondary cracks and wing-shaped cracks at both ends of the central fracture under cyclic loading. This study provides new insights into the fatigue damage mechanism of fractured rock mass under cyclic loading, which is of great significance for solving the safety and technical problems of mining.

在矿产资源开发过程中，强烈的开挖扰动加上非均质裂隙岩体给采矿工程带来了巨大的挑战。本研究结合声发射（AE）和数字成像相关（DIC）等监测技术，对中部边界裂缝性砂岩和完整砂岩进行了不同最大循环载荷下的循环加载试验。综合分析了不同最大循环荷载作用下砂岩的疲劳损伤机理和裂纹演化规律。结果表明：在循环荷载作用下，裂缝的存在显著降低了岩石的峰值强度，改变了岩石的破坏模式；岩石的疲劳变形、强度、疲劳寿命、动弹性模量和阻尼比均受最大循环荷载的影响。最大循环荷载会对砂岩产生“循环强化效应”和“循环弱化效应”。基于声发射参数，我们发现试样的b值和能量计数在接近疲劳破坏时出现波动。在循环荷载作用下，试样表现为拉伸为主的混合破坏。在循环荷载作用下，破碎砂岩在中心裂缝两端发育次生裂缝和翼状裂缝。本研究对循环荷载作用下裂隙岩体疲劳损伤机理提供了新的认识，对解决矿山开采的安全和技术问题具有重要意义。

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引用次数: 0

Fracture behavior of thermally-damaged granite containing pre-existing central hole and cross-flaws under uniaxial loading: Experiments and finite difference modeling 含预先存在的中心孔和交叉缺陷的热损伤花岗岩在单轴载荷下的断裂行为：实验和有限差分模型

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-19 DOI: 10.1016/j.tafmec.2025.105417

Lan Zeng , Xuqi Liang , Shi Liu

The interaction of thermal damage and rock pre-existing flaws in deep underground environments is crucial for understanding deep rock engineering design. Uniaxial load experiments and simulations were performed on granite that had pre-existing central hole and cross-flaws exposed to varying temperatures. Five heterogeneity models of rock masses with different dip angles were established, considering random mineral composition. The thermal damage state of granite subjected to laboratory heat treatments was assessed. The macroscopic crack, represented by softened plastic strain, and the evolution of the displacement field were investigated. The following results were obtained. During the simulated heating at 10 °C/min, thermally induced microcracks occurred due to an increase in plastic tensile strain, while the plastic shear strain was still small until 750 °C. At the same temperature, the relationship between the peak stress and the dip angle was inverted V-shaped. The peak stress increased and decreased with the crack dip angle and reached the maximum at a dip angle of 45°. The stress-strain curves from the experiment and simulation showed similar trends. The failure types consisted of initial shear or tensile failure, followed by tensile-shear failure in the yield softening stage. The evolution of failure modes in heat-treated models is driven by the thermal degradation of key mechanical parameters, including cohesion and tensile strength. Except for the 45° samples, which showed major cracks along the tips of a pre-existing flaws pair in a straight line, all other samples developed cracks at the ends of the pair, near the horizontal direction. The evolution of the Z-direction displacement field and velocity vector showed that the specimen's ultimate failure was caused by crack initiation and propagation along the pre-existing crack tip, followed by sliding. This study provides insights for the stability assessment of deep underground engineering structures affected by high temperature geothermal.

在深部地下环境中，热损伤与岩石预先存在缺陷的相互作用是理解深部岩石工程设计的关键。在不同温度条件下，对具有中心孔和交叉缺陷的花岗岩进行了单轴载荷实验和模拟。考虑随机矿物组成，建立了5种不同倾角岩体的非均质性模型。对实验室热处理后花岗岩的热损伤状态进行了评价。研究了以软化塑性应变为代表的宏观裂纹和位移场的演化规律。得到了以下结果：在10°C/min的模拟加热过程中，由于塑性拉伸应变的增加而产生热致微裂纹，而塑性剪切应变在750°C之前仍然很小。在相同温度下，峰值应力与倾角呈倒v型关系。峰值应力随裂纹倾角的增大而减小，在倾角为45°时达到最大值。实验和模拟得到的应力-应变曲线呈现出相似的趋势。破坏类型主要为初始剪切破坏或拉伸破坏，其次是屈服软化阶段的拉剪破坏。热处理模型的破坏模式演变是由关键力学参数（包括内聚力和抗拉强度）的热退化驱动的。除了45°试样沿已存在的缺陷对的尖端呈直线状出现主要裂纹外，所有其它试样都在靠近水平方向的缺陷对的末端出现裂纹。z向位移场和速度矢量的演化表明，试样的最终破坏是由裂纹萌生和沿裂纹尖端扩展引起的，然后是滑动。该研究为高温地热作用下深部地下工程结构的稳定性评价提供了参考。

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引用次数: 0

Multi-scale fatigue crack growth prediction via a stage-aware and adaptive fusion model 基于阶段感知自适应融合模型的多尺度疲劳裂纹扩展预测

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-19 DOI: 10.1016/j.tafmec.2025.105411

Sheng-xuan Diao , Jin-yong Xiao , Fang Liu , Yong-bao Chen , Jie Yang

The fatigue crack growth process typically exhibits nonlinear evolution across multiple scales, with distinct controlling mechanisms operating between microscopic and macroscopic stages. To overcome the limitations of traditional prediction approaches in modeling scale-dependent behaviors and multivariable coupling mechanisms, this study proposes a multi-scale stage-aware multi-task prediction network (MSMP-Net), with 304 austenitic stainless steel as the material system, aiming to improve modeling accuracy and generalization capability across different crack growth scales. First, a stage embedding mechanism (SEM) is introduced to achieve a learnable representation of crack stage information, thereby enhancing the model's ability to perceive stage semantics. On this basis, multi-scale subnetworks (MS) are constructed according to the differences in physical mechanisms at various scales of crack growth. These subnetworks are further integrated through a dynamic attention fusion (DAF) mechanism, forming a scale-embedded regression network (SERN) that enables selective integration of stage-specific features, thereby enhancing cross-scale feature modeling. In addition, by introducing an auxiliary task of crack stage classification, a multi-task learning mechanism (MTLM) is developed to improve model structural stability and enforce training-stage consistency. The results demonstrate that the MSMP-Net achieves higher predictive accuracy and stronger stage discrimination across three representative crack growth scales (MSC, PSC, and LC). Furthermore, SHAP-based interpretability analysis reveals that the dominant features identified by the model align well with the underlying physical mechanisms of crack growth at different scales, confirming that the proposed model achieves strong predictive performance while maintaining robust physical interpretability.

疲劳裂纹扩展过程具有典型的多尺度非线性演化特征，在微观和宏观阶段具有不同的控制机制。为了克服传统预测方法在模拟尺度依赖行为和多变量耦合机制方面的局限性，本文提出了以304奥氏体不锈钢为材料系统的多尺度阶段感知多任务预测网络（MSMP-Net），旨在提高不同裂纹扩展尺度的建模精度和推广能力。首先，引入阶段嵌入机制实现裂缝阶段信息的可学习表示，从而增强模型对阶段语义的感知能力。在此基础上，根据不同裂纹扩展尺度下物理机制的差异，构建多尺度子网络。这些子网通过动态注意力融合（DAF）机制进一步集成，形成尺度嵌入回归网络（SERN），可以选择性地集成特定阶段的特征，从而增强跨尺度特征建模。此外，通过引入裂缝阶段分类的辅助任务，提出了一种多任务学习机制（MTLM），以提高模型结构的稳定性和增强训练阶段的一致性。结果表明，MSMP-Net在三个代表性裂纹扩展尺度（MSC、PSC和LC）上具有较高的预测精度和较强的阶段识别能力。此外，基于shap的可解释性分析表明，该模型识别的主要特征与不同尺度下裂缝扩展的潜在物理机制很好地吻合，证实了该模型在保持稳健的物理可解释性的同时取得了较强的预测性能。

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引用次数: 0

Damage evolution and fracture behavior characterization in nuclear graphite by inverse finite element analysis 核石墨损伤演化及断裂行为的反演有限元分析

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-18 DOI: 10.1016/j.tafmec.2025.105414

Jie Shen , Shigui Zhao , Yuxiang Tang , Hongniao Chen

Accurate characterization of damage evolution and fracture behavior in nuclear graphite is crucial for the safe design and structural integrity of graphite components. This study investigates fine-grained nuclear graphite (IG110) through three-point bending tests on both plain and single-edge-notched beams with notch-depth ratios ranging from 0.1 to 0.5. Full-field surface deformation was captured using digital image correlation (DIC), and internal fracture events were monitored by acoustic emission (AE). To characterize the tension-compression asymmetry in the mechanical response, a bi-scalar damage constitutive model was developed. Its parameters were identified through inverse finite element analysis, based on DIC-measured strain fields from plain beams. Building on this, the model was integrated with a cohesive crack model (CCM), and an exponential tensile softening curve (TSC) was calibrated by minimizing the absolute error between experimental and simulated crack-opening displacement (COD) profiles. The finite element model using the identified parameters accurately reproduces the load–displacement curves, strain fields, and COD fields. Additionally, analyses of the fracture process zone (FPZ) from both simulations and experiments reveal a three-stage development—rising, plateau, and descending—with the FPZ length during the plateau stage remaining nearly constant (∼4.3 mm) across notch-depth ratios. The average cohesive fracture energy G_fa increases with crack extension before the FPZ is fully developed, exhibiting a diminishing growth rate, and subsequently stabilizes at approximately 180 N/m. Furthermore, partitioning the cumulative dissipated energy into contributions from main-crack extension and diffuse damage shows that diffuse damage accounts for approximately 13% experimentally and about 8.7% numerically. Finally, the temporal evolution of AE events reflects the three FPZ stages. Concurrently, their spatial distribution correlates positively with the numerically predicted width of the tensile damage zone, and both progressively narrow during crack propagation.

准确表征核石墨的损伤演化和断裂行为对石墨构件的安全设计和结构完整性至关重要。本研究对细粒核石墨（IG110）在缺口深度比为0.1 ~ 0.5的平面和单边缺口梁上进行三点弯曲试验。利用数字图像相关技术（DIC）捕捉地表的全场变形，利用声发射技术（AE）监测内部破裂事件。为了描述力学响应中的拉压不对称性，建立了双标量损伤本构模型。基于dic测量的平梁应变场，通过反有限元分析确定了其参数。在此基础上，将该模型与内聚裂纹模型（CCM）相结合，通过最小化实验与模拟裂纹张开位移（COD）曲线之间的绝对误差，对指数拉伸软化曲线（TSC）进行校准。利用识别的参数建立的有限元模型能够准确地再现荷载-位移曲线、应变场和COD场。此外，通过模拟和实验对断裂过程带（FPZ）进行分析，发现其发育分为上升、平台和下降三个阶段，平台阶段的FPZ长度在缺口深度比中几乎保持不变（约4.3 mm）。在FPZ完全发育之前，平均黏聚断裂能Gfa随着裂纹的扩展而增加，并呈现出逐渐减小的增长速率，随后稳定在180 N/m左右。此外，将累积耗散能量划分为主裂纹扩展和弥散损伤的贡献表明，弥散损伤在实验中约占13%，在数值上约占8.7%。最后，声发射事件的时间演变反映了FPZ的三个阶段。同时，它们的空间分布与数值预测的拉伸损伤区宽度呈正相关，并且在裂纹扩展过程中逐渐变窄。

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引用次数: 0

Unified characterization of thickness effects on ductile fracture toughness using a novel out-of-plane constraint parameter 用一种新的面外约束参数统一表征厚度对韧性断裂的影响

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-18 DOI: 10.1016/j.tafmec.2025.105408

Yuqi Zhou , Yi Miao , Lei Zhao , Lianyong Xu , Kai Song , Yongdian Han , Kangda Hao

A new out-of-plane constraint parameter, Q_m^⁎, is proposed to capture fracture toughness evolution of 316 stainless steel at 550 °C under large-scale yielding (LSY). Unlike conventional measures, Q_m^⁎ is load-independent and remains stable across specimen geometries and thicknesses, as confirmed by finite element analyses of C(T), SEN(B), and SEN(T) configurations. Crack propagation was modeled using a Rice–Tracey damage framework, producing J–R curves consistent with experiments. By correlating resistance parameters with Q_m^⁎, a generalized transformation method was established to predict J–R curves across different geometries and sizes from limited test data. This approach decouples geometry effects from intrinsic material behavior, enabling constraint-corrected fracture toughness evaluation with reduced experimental cost. The proposed framework demonstrates broad applicability for constraint-based modeling of ductile fracture and offers a transferable methodology for structural integrity assessments under service conditions.

提出了一种新的面外约束参数Qm - f，用于描述316不锈钢在550℃大规模屈服（LSY）条件下的断裂韧性演变。与传统测量方法不同，Qm是载荷无关的，并且在试样几何形状和厚度上保持稳定，这一点已被C(T)、SEN(B)和SEN(T)结构的有限元分析所证实。采用Rice-Tracey损伤框架对裂纹扩展进行建模，得到与实验结果一致的J-R曲线。通过将电阻参数与Qm ω相关联，建立了一种从有限的试验数据中预测不同几何形状和尺寸的J-R曲线的广义变换方法。这种方法将几何效应与材料的固有特性分离开来，从而降低了实验成本，实现了约束校正断裂韧性评估。提出的框架证明了基于约束的韧性断裂建模的广泛适用性，并为服役条件下的结构完整性评估提供了一种可转移的方法。

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引用次数: 0

Experimental study on the mechanical properties of soft rock under the coupling effect of multi-characteristic fissure and NPR anchorage 多特征裂隙与NPR锚固耦合作用下软岩力学特性试验研究

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-18 DOI: 10.1016/j.tafmec.2025.105413

Chenlei Guo , Zhigang Tao , Peng Tang , Li Cui

The widely distributed fissures in natural rock masses and their multi-characteristic coupling effects significantly influence the mechanical properties of soft rock. Based on orthogonal experimental design, this study compares the mechanical responses of NPR (Negative Poisson's Ratio) and PR (Poisson's Ratio) anchored bodies under the coupling effect of different fissure characteristics (fissure dip angle, fissure spacing, Fissure area). The results show that the peak strength of the NPR anchored body is up to 24 % higher than that of the PR anchored body, and the residual strength is up to 84 % higher. When the prefabricated fissure dip angle is 0°, the rock mass experiences tensile failure; when the fissure dip angle exceeds 30°, the rock mass undergoes shear or tensile-shear failure along the prefabricated fissure direction. Range analysis and analysis of variance reveal that fissure dip angle is the most significant factor affecting the strength of the anchored rock mass, followed by fissure area, and finally fissure spacing. By analyzing the mean strength and F-values, it is found that the extent of strength improvement offered by NPR anchored rock masses over PR anchored rock masses varies under different fissure characteristics. Introducing the residual-to-peak strength ratio (residual strength divided by peak strength) as a toughness index, the mean residual-to-peak ratio for NPR anchored rock masses ranges from 0.72 to 0.98, which is higher than the range of 0.47 to 0.68 for PR anchored rock masses. This demonstrates that NPR bolts can effectively enhance both the strength and toughness of fissured rock masses. A quadratic nonlinear model was employed to fit the theoretical formula. The fitting results indicate that the model exhibits high accuracy and provides a good representation for predicting residual strength.The findings provide a reference for the support design of engineering projects in fissured soft rock.

天然岩体中广泛分布的裂隙及其多特征耦合效应对软岩的力学特性有重要影响。基于正交试验设计，比较了不同裂隙特征（裂隙倾角、裂隙间距、裂隙面积）耦合作用下NPR（负泊松比）和PR（泊松比）锚固体的力学响应。结果表明，NPR锚固体的峰值强度比PR锚固体高24%，残余强度比PR锚固体高84%。预制裂隙倾角为0°时，岩体发生拉伸破坏；当裂隙倾角超过30°时，岩体沿预制裂隙方向发生剪切或拉剪破坏。极差分析和方差分析表明，裂缝倾角是影响锚固岩体强度的最显著因素，其次是裂缝面积，最后是裂缝间距。通过对平均强度和f值的分析，发现在不同的裂隙特征下，NPR锚固岩体比PR锚固岩体的强度提高程度不同。引入残峰强度比（残峰强度除以峰值强度）作为韧性指标，NPR锚固岩体的残峰比均值为0.72 ~ 0.98，PR锚固岩体的残峰比均值为0.47 ~ 0.68。这表明，NPR锚杆可以有效地提高裂隙岩体的强度和韧性。采用二次非线性模型拟合理论公式。拟合结果表明，该模型具有较高的精度，为预测残余强度提供了较好的表征。研究结果可为裂隙软岩中工程项目的支护设计提供参考。

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引用次数: 0

Temperature-dependent influence mechanisms of ice-filled fractures on the dynamic fracture behavior of frozen sandstone 填冰裂缝对冰冻砂岩动力断裂行为的温度影响机制

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-17 DOI: 10.1016/j.tafmec.2025.105412

Cuigang Chen , Zilong Zhou , Xin Cai , Haoyang Fan , Fanjunhui Mo , Chu Wang , Jiaxing Ding , Chunping Lin

In cold regions, ice formed by the freezing of water in rock fractures alters the fracture properties of rocks, significantly affecting the stability and safety of engineering structures. To investigate the effect of ice-filled fractures on the fracture behavior of rock, dynamic fracture tests were conducted on specimens with and without ice-filled fractures under different freezing temperatures. Crack propagation was captured using digital image correlation (DIC) and high-speed camera. Scanning electron microscopy (SEM) was used to observe the fracture surface morphology, and fragment size was quantified through sieving and image analysis. The effects of ice bridge and frost heave induced by ice-filled fractures on rock fracture behavior were systematically discussed. Results show that for specimens without ice, fracture toughness, fracture energy, and crack propagation speed increase as temperature decreases. The fracture mode changes from joint fracture to quasi-joint fracture and tearing ridge failure, with an increase in fragment size. In contrast, specimens with ice-filled fractures exhibit a nonlinear response to temperature. Fracture toughness and energy peak at −30 °C but drop sharply at −40 °C. Crack propagation speed is lowest at −30 °C but slightly increases at −40 °C due to frost heave-induced microcracks. Between −10 °C and − 30 °C, multi-level joint structures form on the fracture surface, with increasing complexity as temperature decreases, then simplify at −40 °C. Fragment size decreases before −30 °C and increases again at −40 °C. Ice-bridging and frost heave effects jointly govern rock fracture behavior, with ice-bridging enhancing integrity, primarily dependent on tensile strength of ice, and frost heave increasing stress concentration at crack tips. This study reveals a dual control mechanism of ice-filled fractures on rock fracture behavior and provides theoretical support for rock engineering in cold regions.

在寒冷地区，岩石裂隙中水的冻结形成的冰改变了岩石的裂隙性质，严重影响工程结构的稳定性和安全性。为研究充冰裂隙对岩石断裂行为的影响，在不同冻结温度下对充冰裂隙存在和不存在的试件进行了动力断裂试验。采用数字图像相关（DIC）和高速摄像机对裂纹扩展过程进行了捕捉。采用扫描电镜（SEM）观察断口表面形貌，并通过筛分和图像分析对断口碎片大小进行量化。系统地讨论了冰桥和冰缝冻胀对岩石断裂行为的影响。结果表明：无冰试样的断裂韧性、断裂能和裂纹扩展速度随温度的降低而增大；断裂模式由关节断裂转变为准关节断裂和撕裂脊破坏，且碎片尺寸增大。相反，含冰裂缝的试样对温度表现出非线性响应。断裂韧性和能量在- 30℃时达到峰值，在- 40℃时急剧下降。在−30°C时，裂纹扩展速度最低，但在−40°C时，由于冻胀引起的微裂纹，裂纹扩展速度略有增加。在- 10°C至- 30°C之间，裂缝表面形成多级节理结构，随着温度的降低，复杂性增加，在- 40°C时简化。在- 30°C之前，碎片大小减小，在- 40°C时再次增大。冰桥效应和冻胀效应共同控制着岩石的破裂行为，冰桥效应增强了岩石的完整性，主要依赖于冰的抗拉强度，而冻胀效应增加了裂缝尖端的应力集中。该研究揭示了充冰裂缝对岩石断裂行为的双重控制机制，为寒区岩石工程提供了理论支持。

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引用次数: 0

Evaluation and quantification of ply configuration effects on mode-I delamination in thin-ply woven composites across loading rates 跨加载率对薄层机织复合材料i型分层影响的评价与量化

IF 5.6 2区工程技术 Q1 ENGINEERING, MECHANICAL

Theoretical and Applied Fracture Mechanics

Pub Date : 2025-12-17 DOI: 10.1016/j.tafmec.2025.105410

Yuqi Zhou , Yang Bai , Yong Cao , Junchao Cao , Chao Zhang

This study addresses the critical challenge of evaluating how ply configuration affects mode-I interlaminar fracture in thin-ply woven composites under different loading rates. A meso-structure-informed finite element modeling strategy is proposed, explicitly incorporating ply architecture to determine dynamic fracture toughness. Additionally, a crack opening displacement (COD)-based approach, coupled with a stiffness coefficient, is developed to assess ply configuration effects. Double cantilever beam (DCB) tests were performed on specimens with ply thicknesses of 0.05 mm, 0.065 mm, and 0.08 mm in unidirectional (UD) and multidirectional (MD) stacking sequences. Pure mode-I fracture at high loading rates (16 m/s, 23 m/s) was achieved using a dual electromagnetic Hopkinson bar system. Under quasi-static loading, ply thickness strongly affects the stiffness coefficient, while its influence diminishes in dynamic loading due to a transition from fiber/matrix interfacial debonding to matrix brittle fracture. Interface angle significantly affects stiffness coefficient in both regimes, with UD stacking showing more tortuous crack paths and higher energy dissipation than MD stacking. Fracture toughness exhibits pronounced positive rate dependence, confirmed by COD-based evaluations and SEM analysis. The findings provide new insights into the loading-rate-dependent fracture behavior of thin-ply woven composites and validate a meso-structure-informed modeling strategy for determining their interlaminar fracture toughness.

本研究解决了评估不同加载速率下层数配置对薄层编织复合材料i型层间断裂的影响这一关键挑战。提出了一种基于细观结构的有限元建模策略，明确地结合层结构来确定动态断裂韧性。此外，还提出了一种基于裂纹张开位移（COD）的方法，并结合刚度系数来评估厚度配置的影响。分别对厚度为0.05 mm、0.065 mm和0.08 mm的试件进行单向（UD）和多向（MD）的双悬臂梁（DCB）试验。采用双电磁霍普金森杆系统，在高加载速率（16 m/s, 23 m/s）下实现了纯i型裂缝。在准静态加载下，层厚对刚度系数的影响较大，而在动态加载下，层厚对刚度系数的影响较小，由纤维/基体界面剥离向基体脆性断裂转变。界面角对两种情况下的刚度系数均有显著影响，UD堆垛比MD堆垛表现出更弯曲的裂纹路径和更高的能量耗散。基于cod的评价和SEM分析证实，断裂韧性表现出明显的正速率依赖性。该研究结果为薄层编织复合材料的加载速率相关断裂行为提供了新的见解，并验证了基于细观结构的建模策略，以确定其层间断裂韧性。

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引用次数: 0