Theoretical and Applied Fracture Mechanics最新文献

{"title":"Study on fracture characteristics of 3D-ILC brittle solids under high-temperature loading in three-point bending","authors":"Haoran Zhang ,&nbsp;Shu Zhu ,&nbsp;Zhende Zhu ,&nbsp;Junyu Wu","doi":"10.1016/j.tafmec.2025.104938","DOIUrl":"10.1016/j.tafmec.2025.104938","url":null,"abstract":"<div><div>This study predicts the mechanical behavior and crack propagation of rock-like materials under high-temperature conditions in deep engineering applications through experimental and numerical simulations. The 3D-ILC method was utilized to induce three-dimensional fissures in a semi-circular disk specimen. The three-point bending test following high-temperature cooling was conducted to analyze the failure mode and fracture morphology. By integrating the maximum tensile stress criterion, M−integral method, and finite element analysis, a thermomechanical simulation of three-dimensional crack propagation is conducted. This reveals the relationship between the stress intensity factor at the crack tip and the relative circumference of the crack front, enabling a detailed visualization of the crack propagation path. The results show that the horizontal single crack extends in a “U”-shaped pattern with increasing temperature, while dynamic fracture occurs along the crack center during the three-point bending test. At high temperatures, crack propagation in the specimens is primarily governed by Mode I, whereas in the three-point bending tests, crack propagation transitions through Modes I, II, and III. This study provides a robust framework for analyzing the mechanical behavior of rock-like materials under thermal and mechanical loading in deep engineering environments.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104938"},"PeriodicalIF":5.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685385","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":"Quantification of the stress field associated with mixed-mode I/II crack initiation considering the pre-existing weak interlayers: A photoelastic experimental study using 3D printed transparent models","authors":"Wang Guo ,&nbsp;Yang Ju ,&nbsp;Chao Chen ,&nbsp;Yihao Zhang ,&nbsp;Guoming Fu","doi":"10.1016/j.tafmec.2025.104926","DOIUrl":"10.1016/j.tafmec.2025.104926","url":null,"abstract":"<div><div>Accurate identifying and describing the full-field stress distribution and fracture parameters at the crack tip in rock structures with primary fractures and weak interlayers lay the groundwork for predicting the structural failure behavior of rock masses. This study utilizes 3D printing to create flat-plate models with weak interlayers and open-inclined cracks. The ten-step phase-shift method is applied to obtain the full-field stress of the model. The stress intensity factors at the crack tip are determined using crack multiparameter stress field equations and the nonlinear over-determined least squares method, with an analysis of the method’s reliability. The study explores the effects of mechanical properties, distribution, and length of weak interlayers on the full-field stress difference and stress intensity factor at the crack tip under uniaxial compression. By conducting experiments on low-temperature uniaxial compression, we conducted an analysis of crack propagation characteristics and the influence exerted by weak interlayers. The results indicate the robust reliability of the combination of the ten-step phase-shift method, the multiparametric equation for the crack tip, and the nonlinear over-determined least squares method in evaluating stress intensity factors at the crack tip. The weak interlayer has the potential to shield the principal stress difference and stress intensity factors <em>K</em>_I and <em>K</em>_II at crack tips, with this shielding effect being influenced by the mechanical properties, distribution, and length of the weak interlayer. The <em>T</em> stress at the crack tip is influenced by the mechanical properties, distribution, and length of the weak interlayer. At −50 ℃, crack propagation undergoes a slow growth stage and a rapid growth stage. The presence of weak interlayers hinders the propagation of cracks and may affect the initiation direction of cracks.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104926"},"PeriodicalIF":5.0,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685308","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":"Numerical simulation of frost heaving deformation of fractured rocks considering heat-force coupling","authors":"Fengqi Shen ,&nbsp;Wenliang Qiu ,&nbsp;Haowei Zhu ,&nbsp;Tianyu Wu ,&nbsp;Lin Qi ,&nbsp;Mingming Xing","doi":"10.1016/j.tafmec.2025.104921","DOIUrl":"10.1016/j.tafmec.2025.104921","url":null,"abstract":"<div><div>Rock engineering in cold regions faces significant challenges due to frost heave deformation in fractured rocks caused by freeze–thaw cycles. There is a lack of methods for modelling frost heaving deformation in fractured rocks. This study proposes a thermo-mechanical coupling model and a numerical simulation method to predict frost heave deformation in fractured rocks. In order to validate the new model and the numerical method, three typical factors affecting the freezing deformation of rocks, which are fracture size, number of fractures and fracture inclination, are considered. The frost heaving deformation of rocks under different fracture conditions is measured by designing and producing a testing device for the frost heaving deformation of fractured rocks. A three-dimensional numerical simulation model of frost heaving in fractured rock is established, and the correctness of the method is verified based on experimental results. The effects of fracture size, fracture number and fracture dip angle on the rock are analyzed, and the validity of the method is verified in two aspects: the overall longitudinal deformation of the rock and the frost heaving pressure. Further, the feasibility of applying the method to the fracture extension is tested. This work provides a reliable tool for assessing frost-related risks in geotechnical engineering, offering critical insights for disaster prevention in cold regions.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104921"},"PeriodicalIF":5.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685371","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":"Microstructure related mechanical response and fatigue crack growth behavior of polymer electrolyte membrane under in-situ loading","authors":"Wei Li ,&nbsp;Xiaobo Cao ,&nbsp;Liang Cai ,&nbsp;Ibrahim Elbugdady ,&nbsp;Yuzhe Jin ,&nbsp;Chuanwen Sun","doi":"10.1016/j.tafmec.2025.104934","DOIUrl":"10.1016/j.tafmec.2025.104934","url":null,"abstract":"<div><div>Polymer electrolyte membrane (PEM) is a key component in fuel cells, however, its mechanical degradation behavior driven by fatigue is not yet well understood. Herein, combined with digital image correlation and microscopic observation, the multiscale mechanical response and crack growth behavior of PEM associated with microstructure were investigated using multiple in-situ tests including uniaxial tensile, stress relaxation and crack growth with different stress ratios. Results show that PEM clearly presents the rate dependence and anisotropy. Combined with the area statistics of hydrophobic main chains before and after tension, the plastic deformation mechanism associated with molecular chain rotation and unwinding was explained, and a modified multilayer viscoelastic-plastic constitutive model in consideration of the effects of plane stress, anisotropy and true stress was developed. Furthermore, based on the analysis of strain field at the near crack-tip, the size of cyclic plastic zone tends to increase with the increasing of crack length and stress ratio, but the effect of crack length on crack growth rate is more significant due to the larger stress concentration effect. Finally, the failure mechanism associated with ligament, tearing plane and resilient fatigue striation was elucidated.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104934"},"PeriodicalIF":5.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685382","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 of mode I fracture resistance of hot mix asphalt using three testing protocols under the low temperature","authors":"Weimin Song,&nbsp;Wenlong Yan,&nbsp;Hao Wu,&nbsp;Zhicai Cui","doi":"10.1016/j.tafmec.2025.104937","DOIUrl":"10.1016/j.tafmec.2025.104937","url":null,"abstract":"<div><div>A variety of testing methodologies are currently employed to assess the fracture behaviors of asphalt mixtures. However, there is a notable variability in fracture parameters, such as the stress intensity factor (SIF) and fracture energy, when derived from different testing approaches. This study investigated the variations in fracture parameters, including the SIF, fracture energy, tensile stiffness index (TSI), and modified tensile stiffness index (MTSI), obtained from three distinct testing methods: the semi-circular bending (SCB) test, the three-point bending (TPB) test, and the semi-circular tension (SCT) test, all conducted under low-temperature conditions. The maximum tangential strain (MTS) criterion was utilized to elucidate the origins of the observed differences among the various fracture assessment methods. Results revealed that the load–displacement curves from the SCB and TPB tests were similar, characterized by a linear escalation in load up to the peak point, followed by a precipitous decline with minimal deformation post-peak load. In contrast, the SCT test exhibited a divergent behavior, with a gradual decrease in load post-peak and noticeable displacements. The TPB tests generated the highest fracture parameters in terms of SIF, fracture energy, and TSI. The SCB tests provided superior results for the SIF and fracture energy compared to the SCT tests. The AC10 mixture demonstrated enhanced fracture resistance relative to the AC16 mixture across all these parameters, which was mainly ascribed to the lower porosity of AC10. The introduction of a modified tensile stiffness index (MTSI) resulted in a lower coefficient of variance (COV) when compared to the traditional TSI, indicating less dispersion was induced among different test methods. Upon employing the MTS criterion in the analysis of fracture, it is determined that the inherent stress intensity factors (<em>K</em>_IC) for both AC10 and AC16 asphalt mixtures exceeded the apparent stress intensity factors (<em>K</em>_If). Furthermore, the consideration of T-stress in the analysis effectively diminished the variability in <em>K</em>_If values observed across the different testing methodologies.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104937"},"PeriodicalIF":5.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685380","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":"On determination of critical strain energy release rate for mode II failure of asphaltic composite mixtures using assymetric SCB configuration","authors":"M.R.M. Aliha ,&nbsp;S.M.N. Ghoreishi ,&nbsp;A. Tavana ,&nbsp;M. Molayem ,&nbsp;N. Choupani","doi":"10.1016/j.tafmec.2025.104936","DOIUrl":"10.1016/j.tafmec.2025.104936","url":null,"abstract":"<div><div>Understanding the crack resistance of hot mix asphalt (HMA) composites under dominantly in-plane shear (mode II) at intermediate temperatures is an important issue for design and life assessment of asphaltic pavements. While at low temperatures the critical value of stress intensity factor (e.g. <em>K</em>_IIc) is often used as the fracture resistance index for asphalt mixtures, the J-index is probably a more reliable fracture parameter for medium temperatures to capture the inelastic behavior of HMA mixture. Accordingly, the concept of J-integral has been adopted for determining <em>J</em>_Ic value of bituminous mixtures under mode I using semi-circular bend (SCB) test. In this paper, this concept is extended to propose an index (called <em>J</em>_IIc) for investigating mode II failure resistance of HMA mixtures. To do that the strain energy values are determined at pure mode II using the multiple asymmetric SCB (ASCB) samples with different crack lengths. Using this method the <em>J</em>_IIc value was determined at 25 °C for four HMA mixtures made of limestone aggrgate-60/70 bitumen (L60), limestone aggregate-85/100 bitumen (L85), siliceous aggregate-60/70 bitumen (S60) and siliceous aggregate-85/100 bitumen (S85). The corresponding values of <em>J</em>_IIc for the investigated asphaltic mixtures varied from 3.5 to 7 kJ/m² that were significantly higher than the <em>J</em>_Ic value of asphaltic mixtures. The <em>J</em>_IIc value obtained from the L60 mixture was greater than the other mixtures and the S85 mixture showed the lowest <em>J</em>_IIc. In addition, corresponding values of critical mode II stress intensity factor and mode II fracture energy were determined for each mixture and their relationships with the <em>J</em>_IIc were investigated. In general, there were no proportional and linear relations between <em>K</em>_IIf, <em>G</em>_IIf and <em>J</em>_IIc in the HMA mixtures.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104936"},"PeriodicalIF":5.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685309","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":"An elastic foundation modeling approach to bi-material interface crack problems of finite bond length","authors":"Yuning Zhang ,&nbsp;Pingsha Dong","doi":"10.1016/j.tafmec.2025.104933","DOIUrl":"10.1016/j.tafmec.2025.104933","url":null,"abstract":"<div><div>There have been some significant advances in direct joining of dissimilar materials over recent years for enabling multi-material lightweight structures. As such, both dissimilar material joint design and structural integrity evaluation call for engineering fracture mechanics solutions to bi-material interface crack problems involving finite bond line length. This paper presents a novel elastic foundation modeling approach to address a set of two-dimensional bi-material interface crack problems. The analytical formulation presented enables the extraction of important length-scale parameters for supporting quantitative joint sizing and interrelating the mixed-mode energy release rates to the classical mode-mixity defined by bi-material crack tip singularity fields. The modeling results can be directly used for analyzing some common test configurations, e.g., “lap-shear” (LS) and “coach-peel” (CP) widely used by industry for ensuring optimal bond line sizing for both satisfactory mechanical performance and easy dis-assembly. To demonstrate the practical implications of this research, a group of bi-material (aluminum to steel) lap-shear fracture tests are modeled through a linear superposition of the solutions of the elementary load cases.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104933"},"PeriodicalIF":5.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685379","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 the dynamic fracture law of layered materials under the explosive load of slotted charge","authors":"Zhongwen Yue ,&nbsp;Xu Wang ,&nbsp;Xingyuan Zhou ,&nbsp;Huang Wang ,&nbsp;Shengnan Xu ,&nbsp;Meng Ren ,&nbsp;Linzhi Peng","doi":"10.1016/j.tafmec.2025.104932","DOIUrl":"10.1016/j.tafmec.2025.104932","url":null,"abstract":"<div><div>Directional fracture blasting with slotted charge is one of the main rock breaking methods for excavating layered rock mass tunnels. This article uses dynamic photoelastic method combined with high-speed photography technology to visualize the process of explosive stress waves and explosive cracks passing through vertical layers of different strengths caused by the explosion of slotted charge. The dynamic fracture law of layered materials with different strength layers under slotted charge explosion loads was studied. The results indicate that the greater the strength of the bedding plane, the more significant the waveform changes of the explosive stress wave when transmitted through the bedding plane. When the strength of the bedding is relatively high, the crack velocity is less affected by the bedding. When the strength of the bedding is weak and there is a significant difference from the strength of the specimen material, the velocity of the crack after passing through the bedding will undergo severe oscillations. Before the main crack reaches the bedding plane and after passing through it, the fracture mode of the crack is mainly mode-I. During the process of the crack passing through the bedding plane, the dynamic crack transforms from the mode-I crack to the mixed mode crack. Under the premise of a certain crack velocity, bedding angle, and physical and mechanical parameters of the specimen, the propagation trajectory of the crack passing through the bedding is related to the difference in bedding strength and specimen strength.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104932"},"PeriodicalIF":5.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642513","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 the evolution of rock fractures induced by rolled static cracking agents in steeply inclined hard faults","authors":"Lei Sun,&nbsp;Chong Li,&nbsp;Yue Cao,&nbsp;Zhijun Xu,&nbsp;Lianhai Tai,&nbsp;Huan Xia,&nbsp;MengHu Sun,&nbsp;Menglong Zha,&nbsp;ShuaiShuai Jiang","doi":"10.1016/j.tafmec.2025.104927","DOIUrl":"10.1016/j.tafmec.2025.104927","url":null,"abstract":"<div><div>The static blasting method is the preferred approach for addressing hard faults within an inclined working face. The presence of shear stress within the inclined rock layers can significantly affect the cracking efficiency of the Rolled Static Cracking Agent(RSCA). To study the rupture damage characteristics of rocks under the expansion of RSCA with different shear stress magnitudes, a novel Compression Shear Coupling Test system (CSCT) was employed. Fracture tests were conducted on RSCA specimens at six different inclination angles (0°, 5°, 10°, 15°, 20°, and 25°) under constant pressure. Acoustic emission monitoring and full-field strain measurement were employed to analyze the dynamic fracture process and damage characteristics of the specimens. The results indicate that an increase in inclination accelerates the crack initiation efficiency of RSCA, causing cracks to propagate at lower expansion pressures. The magnitude of the shear stress component significantly affects the fracturing characteristics of the specimens; as the inclination increases, the proportion of shear cracks in the specimens increases significantly. Additionally, the AE energy, fractal dimension, and surface density of cracks initially decrease and then increase. The distribution of surface strain concentration areas is closely related to the inclination angle, with shear stress causing the maximum tensile stress point to shift towards the shear direction of the specimen, forming strip-shaped damage zones. As a key factor affecting rock fracturing, the shear stress component alters the crack propagation pattern during RSCA fracturing. The research results provide data support and theoretical reference for field applications.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104927"},"PeriodicalIF":5.0,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143636855","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 residual stress on sulfide stress cracking and fracture toughness in carbon steel: A phase-field modeling approach","authors":"Alok Negi ,&nbsp;Imad Barsoum","doi":"10.1016/j.tafmec.2025.104911","DOIUrl":"10.1016/j.tafmec.2025.104911","url":null,"abstract":"<div><div>The susceptibility of OCTG-grade alloys to sulfide stress cracking (SSC) in hydrogen sulfide (H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>S)-rich sour environments poses a unique challenge for downhole oil and gas exploration, particularly when considering the role of residual stresses. These stresses, inherent in materials from fabrication processes, can strongly influence their cracking resistance even in the absence of external loads. This study numerically examines the effect of residual stresses on the fracture toughness (<span><math><msub><mrow><mi>K</mi></mrow><mrow><mi>ISSC</mi></mrow></msub></math></span>) measurements associated with SSC resistance of a high-strength low-alloy carbon steel C110 in H<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>S-containing aqueous test solution using industry-standard single-edge notched tension (SENT) and double-cantilever beam (DCB) testing methodologies. Residual stresses are measured on pipe samples and are incorporated into the finite element model of the pipe through a thermo-mechanical equivalent loading. The residual stress field is then mapped onto the fracture mechanics test specimens to represent the initial stress distributions. A coupled deformation-diffusion phase-field framework is implemented in COMSOL to simulate crack propagation under the combined influence of residual stress and environmental factors. The results offer insights into SSC mechanisms, demonstrating that elevated residual stress levels in both SENT and DCB tests affect SSC initiation thresholds and arrest, signifying reduced fracture toughness and increased susceptibility to SSC. This study underscores the importance of considering residual stresses in fracture-mechanics-based SSC integrity assessments to improve the reliability of components in sour service applications.</div></div>","PeriodicalId":22879,"journal":{"name":"Theoretical and Applied Fracture Mechanics","volume":"138 ","pages":"Article 104911"},"PeriodicalIF":5.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644928","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}