Comparison of H-B and M-C Failure Criterion at Low Confinement and their Impact on the Prediction of Failure Zone Around an Underground Metal Mine

Outburst cavity formed during coal and gas outburst can be pear shaped, elliptical, or just like an irregularly elongated ellipsoid, its capacity is always smaller than the volume of ejected coal. And the gas emission quantity is almost 4 to 10 times as gas content in ejected coal. These are two different expressions of the same problem. To find the reasons for the decrease of outburst cavity volume and the increase of gas emission quantity per ton, by using the finite element code ANSYS, the damage zone and the failure zone of the outburst cavity were determined based on the static and dynamic combination method. In this paper, the reason for the decrease of the outburst volume was explained.

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Determination of a New Failure Criterion for Rock Mass and Concrete

Geotechnical and Geological Engineering ◽

10.1007/s10706-021-01728-9 ◽

2021 ◽

Author(s):

Roberto Ucar

Keyword(s):

Rock Mass ◽

Failure Criterion

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Mechanical performance and failure criterion of coral concrete under combined compression-shear stresses

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.123050 ◽

2021 ◽

Vol 288 ◽

pp. 123050

Author(s):

Bing Liu ◽

Jingkai Zhou ◽

Xiaoyan Wen ◽

Jianhua Guo ◽

Zhiheng Deng ◽

...

Keyword(s):

Failure Criterion ◽

Mechanical Performance ◽

Shear Stresses

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Mesoscale Modelling of Concretes Subjected to Triaxial Loadings: Mechanical Properties and Fracture Behaviour

Materials ◽

10.3390/ma14051099 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1099

Author(s):

Qingqing Chen ◽

Yuhang Zhang ◽

Tingting Zhao ◽

Zhiyong Wang ◽

Zhihua Wang

Keyword(s):

Mechanical Properties ◽

Tensile Stress ◽

Failure Criterion ◽

Mesoscale Model ◽

Fracture Behaviour ◽

Descent Method ◽

Triaxial Stress ◽

Gradient Descent Method ◽

Stress States ◽

Shear Failures

The mechanical properties and fracture behaviour of concretes under different triaxial stress states were investigated based on a 3D mesoscale model. The quasistatic triaxial loadings, namely, compression–compression–compression (C–C–C), compression–tension–tension (C–T–T) and compression–compression–tension (C–C–T), were simulated using an implicit solver. The mesoscopic modelling with good robustness gave reliable and detailed damage evolution processes under different triaxial stress states. The lateral tensile stress significantly influenced the multiaxial mechanical behaviour of the concretes, accelerating the concrete failure. With low lateral pressures or tensile stress, axial cleavage was the main failure mode of the specimens. Furthermore, the concretes presented shear failures under medium lateral pressures. The concretes experienced a transition from brittle fracture to plastic failure under high lateral pressures. The Ottosen parameters were modified by the gradient descent method and then the failure criterion of the concretes in the principal stress space was given. The failure criterion could describe the strength characteristics of concrete materials well by being fitted with experimental data under different triaxial stress states.

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Flexural bearing capacity and failure mechanism of CFRP-aluminum laminate beam with double-channel cross-section

Science and Engineering of Composite Materials ◽

10.1515/secm-2021-0012 ◽

2021 ◽

Vol 28 (1) ◽

pp. 139-152

Author(s):

Teng Huang ◽

Dongdong Zhang ◽

Yaxin Huang ◽

Chengfei Fan ◽

Yuan Lin ◽

...

Keyword(s):

Carbon Fiber ◽

Bearing Capacity ◽

Failure Mechanism ◽

Cross Section ◽

Failure Criterion ◽

Failure Modes ◽

Channel Cross Section ◽

Fiber Layer ◽

Flexural Bearing Capacity ◽

Double Channel

Abstract In this study, the flexural bearing capacity and failure mechanism of carbon fiber-reinforced aluminum laminate (CARALL) beams with a double-channel cross-section and a 3/2 laminated configuration were experimentally and numerically studied. Two types of specimens using different carbon fiber layup configurations ([0°/90°/0°]3 and [45°/0°/−45°]3) were fabricated using the pressure molding thermal curing forming process. The double-channel CARALL beams were subjected to static three-point bending tests to determine their failure behaviors in terms of ultimate bearing capacity and failure modes. Owing to the shortcomings of the two-dimensional Hashin failure criterion, the user-defined FORTRAN subroutine VUMAT suitable for the ABAQUS/Explicit solver and an analysis algorithm were established to obtain a progressive damage prediction of the CFRP layer using the three-dimensional Hashin failure criterion. Various failure behaviors and mechanisms of the CARALL beams were numerically analyzed. The results indicated that the numerical simulation was consistent with the experimental results for the ultimate bearing capacity and final failure modes, and the failure process of the double-channel CARALL beams could be revealed. The ultimate failure modes of both types of double-channel CARALL beams were local buckling deformation at the intersection of the upper flange and web near the concentrated loading position, which was mainly caused by the delamination failure among different unidirectional plates, tension and compression failure of the matrix, and shear failure of the fiber layers. The ability of each fiber layer to resist damage decreased in the order of 90° fiber layer > 0° fiber layer > 45° fiber layer. Thus, it is suggested that 90°, 0°, and 45° fiber layers should be stacked for double-channel CARALL beams.

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Experimental and numerical studies on failure and energy absorption of composite thin-walled square tubes under quasi-static compression loading

International Journal of Nonlinear Sciences and Numerical Simulation ◽

10.1515/ijnsns-2019-0062 ◽

2020 ◽

Vol 21 (6) ◽

pp. 623-634

Author(s):

Haolei Mou ◽

Zhenyu Feng ◽

Jiang Xie ◽

Jun Zou ◽

Kun Zhou

Keyword(s):

Finite Element ◽

Shell Model ◽

Energy Absorption ◽

Failure Mode ◽

Failure Criterion ◽

Finite Element Models ◽

Static Compression ◽

Compression Loading ◽

Thin Walled ◽

Simulation Results

AbstractTo analysis the failure and energy absorption of carbon fiber reinforced polymer (CFRP) thin-walled square tube, the quasi-static axial compression loading tests are conducted for [±45]3s square tube, and the square tube after test is scanned to further investigate the failure mechanism. Three different finite element models, i.e. single-layer shell model, multi-layer shell model and stacked shell mode, are developed by using the Puck 2000 matrix failure criterion and Yamada Sun fiber failure criterion, and three models are verified and compared according to the experimental energy absorption metrics. The experimental and simulation results show that the failure mode of [±45]3s square tube is the local buckling failure mode, and the energy are absorbed mainly by intralaminar and interlaminar delamination, fiber elastic deformation, fiber debonding and fracture, matrix deformation cracking and longitudinal crack propagation. Three different finite element models can reproduce the collapse behaviours of [±45]3s square tube to some extent, but the stacked shell model can better reproduce the failure mode, and the difference of specific energy absorption (SEA) is minimum, which shows the numerical simulation results are in better agreement with the test results.

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