Article
Engineering, Mechanical
Dongliang Sun, Qiuhua Rao, Shanyong Wang, Qingqing Shen, Wei Yi
Summary: This study measured the Mode II fracture toughness of anisotropic shale using a shearbox test, proposing new physical factors to describe stress intensity factors on the original crack plane. Results showed that the predicted Mode II fracture planes aligned well with tested fracture trajectories and the toughness increased with a certain angle, providing valuable insights for shale-gas exploitation technology.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Mechanics
Yanlin Wang, Weigang Wang, Bohua Zhang, Yadong Bian, Chun-Qing Li
Summary: This paper experimentally investigates the fracture resistance and behavior of two grades of mild steel under various in-plane loading combinations, revealing the sensitivity of steel fracture resistance to mode mixity. Factors such as plastic strain concentration, crack tip blunting, and fracture mechanism are found to lead to different fracture resistance of the two types of steel under various mixed mode loading combinations. Testing results suggest the necessity of considering mode mixity effect in practical engineering applications, especially under mode II loading dominance.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Mechanics
D. C. Goncalves, I. J. Sanchez-Arce, L. D. C. Ramalho, R. D. S. G. Campilho, J. Belinha
Summary: In this study, a fracture propagation algorithm is extended to analyze mixed-mode fracture propagation in adhesively bonded joints. Single-leg bending (SLB) specimens were experimentally tested to characterize the adhesive joint and validate the numerical application. The radial point interpolation method (RPIM), a meshless method, was used for numerical analysis to obtain the mechanical response of the specimen at each crack tip increment.
COMPOSITE STRUCTURES
(2023)
Article
Engineering, Mechanical
Quanqi Zhu, Diyuan Li, Jinyin Ma, Zhenyu Han, Xibing Li
Summary: The dynamic mixed mode I/II fracture properties of hard rock were investigated through split-Hopkinson pressure bar tests on cracked straight through Brazilian disc (CSTBD) diorite specimens. The fracture load and toughness for different crack angles or mode mixities were determined. The dynamic fracture process and crack mouth opening displacement (CMOD) were monitored, and the fractal and morphology characteristics of fracture surfaces were analyzed. The study found that the CMOD behavior is closely related to the force acting on the crack surface, and the allowable CMOD decreases with increasing crack angle. Stress-based and strain-based fracture criteria were introduced, and the GMTS criterion and EMTSN criterion showed the best prediction effect for fracture toughness and crack initiation angle respectively. Observation results showed that the macro fracture trajectories were controlled by the prefabricated crack angle, while the mode mixity had little impact on the meso-roughness and micro-morphology of the fracture surface. The fracture surface of CSTBD diorite specimen exhibited mixed tensile-shear cracks under dynamic load.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Engineering, Mechanical
Zelin Liu, Chunde Ma, Xin'ao Wei
Summary: Fracture characteristics of layered rocks under mixed mode I/III loading are significantly influenced by bedding angle alpha and loading mode. The equivalent fracture toughness and fracture energy exhibit different trends under different loading modes and bedding angles. The acoustic emission characteristics and fracture trajectory are also significantly influenced by bedding angle, loading mode, and bedding strength. The results provide new insights into the mixed mode I/III fracture mechanism of layered rocks.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Chemistry, Multidisciplinary
Jingang He, Yuanjie Meng, Jun You, Jin Zhang, Yuanzhuo Wang, Cheng Zhang
Summary: An improved adaptive high-order sliding mode trajectory tracking controller is proposed in this paper to resolve the problem of high-precision trajectory tracking control in a missile's mid-guidance phase under interference conditions. By constructing open-loop nominal trajectories and designing a nonlinear sliding mode surface and an adaptive high-order sliding mode approaching law, a high-precision trajectory tracking controller is developed. Simulation results show that the proposed method achieves faster convergence and improved tracking effect compared to other methods.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Mechanical
You Wu, Tubing Yin, Dengdeng Zhuang, Yongjun Chen, Jiexin Ma, Wenxuan Guo
Summary: The initiation and propagation of cracks in rock bodies were studied using digital image correlation technique, and the initial fracture toughness and unstable fracture toughness of specimens under different crack angles were obtained. The study showed that the crack is in the elastic state before reaching the crack initiation load, then propagates stably until it reaches the peak load where it becomes unstable and uncontrollable. The initial fracture toughness and crack propagation angle of the specimens were consistent with the predictions of the MTS criterion. Moreover, the mode of fracture transformed into pure mode I with crack extension.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Construction & Building Technology
Yuzhu Guo, Xudong Chen, Jin Wu, Yingjie Ning, Tao Ji
Summary: A four-point shear (FPS) test was conducted to investigate the mixed mode fracture characteristics of the shotcrete-rock interface. Real-time monitoring of the fracture process was achieved using acoustic emission (AE) and digital image correlation (DIC) techniques. The mechanical test results indicate that residual stress increases with modal Angle or roughness under the same crack mouth opening displacement (CMOD). The crack morphology and damage mechanism of the granite-shotcrete interface change as the modal angle increases.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Multidisciplinary
S. Ali Faghidian, Krzysztof Kamil Zur, J. N. Reddy
Summary: The proposed higher-order unified gradient elasticity theory effectively characterizes the nanoscopic response of advanced nano-materials, as demonstrated by its application to study the torsional behavior of elastic nano-bars and determine the shear modulus of nano-sized bars in closed-form analytical formula. Additionally, a practical approach to calibrate characteristic lengths is introduced.
INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
(2022)
Article
Mechanics
Tianhao Yang, Vatsa Gandhi, Rui Huang, Kenneth M. Liechti
Summary: This paper describes the development of a dual-actuator loading device and its application in studying the crack growth behavior and J-integral parameters of laminated beam specimens. The results show that the stiffness of the silicon/epoxy interface and the crack growth parameters are independent of the separation rate and mode-mix. However, the change in mode-mix leads to non-monotonic behavior in the critical J-integral.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Engineering, Mechanical
Saeid Hashemian, Peyman Mashhadi Keshtiban, Abuzar Es'haghi Oskui
Summary: This study investigated the formability of Al 7057T6 alloy and the crack growth behavior under different loading modes. It was found that the alloy exhibited higher resistance against crack growth in the pure tensile mode, and this resistance decreased with higher forging percentages. The decline was negligible in mode-I, but intensified in mode-II with an increase in the loading angle.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Engineering, Mechanical
Mohammad R. Mehraban, Majid R. Ayatollahi, Bahador Bahrami, Filippo Berto
Summary: This study investigates the effects of higher order terms on the stress and displacement fields around sharp V-notched components under pure antiplane shear loading. The use of nonsingular terms is necessary only when seeking stress distribution far from the notch tip and with small notch angles. Parameters affecting accurate determination of unknown coefficients and convergence of the numerical results were also studied to check the stability of the results.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Engineering, Mechanical
Haijian Su, Xiaofeng Qin, Yujie Feng, Liyuan Yu, Zizheng Sun
Summary: In this paper, dynamic impact loading tests were conducted on heat-treated CSTBD granite specimens using the SHPB system. The effects of temperature and loading mode on fracture toughness, fracture growth path, strain distribution, and fracture angle were analyzed.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Mechanics
S. Pouresmaeeli, B. G. Falzon
Summary: This paper presents a comprehensive stochastic analysis of pure and mixed mode interlaminar fracture of fibre-reinforced polymer (FRP) composites using different uncertainty quantification approaches. The study aims to evaluate the accuracy and computational cost of stochastic reduced order models in finite element modelling of FRP composite fracture. The results show that combining a stochastic reduced order model with a surrogate model can achieve computational efficiency with a high level of accuracy even with a limited number of samples.
COMPOSITE STRUCTURES
(2021)
Article
Construction & Building Technology
Kaiming Pan, Rena C. Yu, Gonzalo Ruiz, Xiaoxin Zhang, Angel De La Rosa, Zhimin Wu
Summary: This study investigates the evolution of the fracture process zone (FPZ) in steel fiber-reinforced concrete under dynamic mixed-mode loading. The experiments were conducted on beams with varying fiber contents and different loading rates, and the crack propagation process was recorded using a high-speed camera. The FPZ was found to extend and then shorten with crack propagation, with its length increasing with the loading rate but decreasing with the fiber content. Moreover, the addition of fibers promoted the generation of multiple FPZs and caused more distributive damage in the matrix. Under impact loading, the cracked matrix and steel fibers worked together to dissipate excessive energy.
CONSTRUCTION AND BUILDING MATERIALS
(2023)