Failure mechanism and constitutive relation for an anchorage segment of an anchor cable under pull-out loading

2020 ◽  
Vol 231 (8) ◽  
pp. 3305-3317 ◽  
Author(s):  
S. R. Wang ◽  
Y. H. Wang ◽  
J. Gong ◽  
Z. L. Wang ◽  
Q. X. Huang ◽  
...  
Keyword(s):  
Failure Mechanism ◽  
Constitutive Relation ◽  
Anchor Cable ◽  
Pull Out

scholarly journals ANCHORING PERFORMANCES ANALYSIS OF TENSION-TORSION GROUTED ANCHOR UNDER FREE AND NON-FREE ROTATING CONDITIONS

10.6036/9985 ◽  
2021 ◽  
Vol 96 (1) ◽  
pp. 166-172
Author(s):  
SHUREN WANG ◽  
YUHAO WANG ◽  
ZELIANG WANG ◽  
JIAN GONG ◽  
CHUNLIU LI
Keyword(s):  
Failure Mechanism ◽  
Progressive Failure ◽  
Theoretical Models ◽  
Calculation Model ◽  
Tensile Shear ◽  
Composite Failure ◽  
Anchor Cable ◽  
Pull Out ◽  
Load Response ◽  
Coupling Characteristics

For the failure mechanism of the anchor cable lags behind the practice demand for theoretical models, Abaqus technique was used to analyze the anchoring performances of the grouted anchor under the conditions of free and non-free rotating. The tension-torsion coupling characteristics and the progressive failure mechanism of the anchorage segment were studied during the pull-out test. The torsion response of the anchorage segment and the internal horizontal and vertical strain changes in the anchoring concrete were also analyzed. Results show that the proposed calculation model of the anchor cable is verified. With the increase of the pulling-out displacement, the load response of the anchored section is gradually transferred from the inside to the outside. The anchoring stress in the concrete undergoes the evolution process of rod shape-bell shape-aquarium shape-spear shape. As an intermediate transition layer, the anchoring agent breaks before the concrete and at the same time that plays a buffering effect. Under the action of tension-torsion coupling, the anchoring agent is prone to tensile-shear composite failure. There are two different ways of transmitting force for the grouted anchor under rotating and non-rotating conditions, and the anchoring force of the anchor cable will be reduced in the state of free rotation. The obtained conclusions can provide a reference for the similar anchoring practice. Keywords: Grouted anchor, Tension-torsion coupling, Numerical simulation, Failure mechanism, Anchoring force

Investigation of the tensile performance and failure mechanism of carbon–aramid hybrid fibers/epoxy sandwich structure laminates using the UV-thermal synergetic curing mechanism: Experimentation and simulation

2018 ◽  
Vol 22 (8) ◽  
pp. 2582-2603
Author(s):  
Jiaojiao Xi ◽  
Xiaoyan Liu ◽  
Zhiqiang Yu
Keyword(s):  
Finite Element ◽  
Failure Mechanism ◽  
Sandwich Structure ◽  
Experimental Results ◽  
Tensile Failure ◽  
Hybrid Fibers ◽  
Pull Out ◽  
Tensile Performance ◽  
Hybrid Laminates ◽  
Curing Agents

The tensile failure mechanism of carbon–aramid hybrid fibers/epoxy sandwich structure laminates was investigated by using experimental and finite element methods. Double curing agents, triarylsulfonium hexafluoroantimonates and triethylene tetramine with a mass ratio of 4:15 were introduced into the laminates. Sandwich structure laminates, with different proportions of hybrid fibers, were cured by UV-initiated anion/cationic dual curing technique. The results showed that the synergetic curing effects of two curing agents were observed under UV irradiation, leading to the better curing of the system, which further plays a positive influence on the mechanical performance. The tensile properties and failure mechanism of the laminates depended on the stacking sequence and fiber volume fractions of the layer structures. The interplay hybrid laminates, containing three alternate plies with fiber contents of 67.7 vol%, presented the optimal tensile performance, and its tensile strength and modulus were 0.82 GPa and 22.09 GPa, respectively. The fracture morphologies revealed that pull-out and debonding of fibers were the main failure mechanism of hybrid laminates. The performance of sandwich structure laminates was determined by the load-carrying capacity of carbon fiber and load-transferring capacity of the aramid fiber and adhesive. The finite element model based on experiments was established to simulate the stress state and failure mechanism of sandwich laminates. The results demonstrated that the stress was better transferred into carbon fibers from the aramid fibers and adhesive, and the relative error rate of maximum stress from finite element analysis and experimental results was less than 5%, which were in reasonable agreement with the experimental results.

scholarly journals Experimental Study on Load-Displacement Relationship of Prestressed Cable in Red Clay Stratum

2018 ◽  
Vol 38 ◽  
pp. 03007
Author(s):  
Yong Xing Ji ◽  
Yuan Jie Xiang ◽  
Xiao Yong Zhao
Keyword(s):  
Damage Index ◽  
Theoretical Models ◽  
Exponential Model ◽  
Red Clay ◽  
Anchor Cable ◽  
Pull Out ◽  
S Curve ◽  
Plastic Displacement ◽  
Relationship Of ◽  
Prestressed Anchor

The P-S curves of prestressed anchor cable are obtained by field pull-out tests in the red-clay stratum in Guiyang area. The P-S curves of different theoretical models are discussed base on the theoretical analysis. The elastic and plastic displacement of prestressed anchor cable are analyzed. The results shows that, the anchoring effect are mainly effected by the red-clay mechanic properties in the red-clay stratum; the P-S curve of anchor bolt can be fitted well by the exponential model and conformed to the actual; the plastic displacement is used to anchor’s damage index are more truthfulness in the red-clay stratum.

scholarly journals Study on the Lagging Support Mechanism of Anchor Cable in Coal Roadway Based on FLAC3D Modified Model

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiangyu Wang ◽  
Guanghui Wang ◽  
Bowen Wu ◽  
Shuaigang Liu
Keyword(s):  
Failure Criteria ◽  
Modified Model ◽  
Support Mechanism ◽  
Anchor Cable ◽  
Pull Out ◽  
Coal Roadway ◽  
Minimum Principal Stress ◽  
Support Resistance ◽  
Initial Support ◽  
Roadway Deformation

Aiming at the broken failure of anchor cable in the mining roadway roof during the mining process, the lagging support scheme of anchor cable is proposed. Based on the results of indoor anchor cable pull-out test, the Cable element in FLAC3D is modified to realize the extension breaking of anchor cable in the calculation process. Furthermore, the minimum principal stress and volume strain rate mutation point are used as the failure criteria of the anchor cable. Through the comparative analysis of five anchor cable lagging support schemes of 6208 transport tunnel in Wangzhuang Mine Coal, the results demonstrate that the lagging support reduces the initial support resistance of the supporting structure. With the increase of lagging time, the ability of anchor cable to adapt to deformation increases gradually. When the lagging time reaches the gentle area of roadway deformation, its ability to adapt to deformation remains stable. Finally, it was determined that the support should start at 10–15 m of the anchor cable lagging head of the 6208 transport tunnel. Industrial tests show that the lagging support scheme ensures that the anchor cable can withstand a certain deformation, and the support body has no broken failure, which effectively controls the large mining-induced deformation of surrounding rock.

Investigation of the Tensile Fracture Behavior of Notched C/SiC Composite Using In Situ SEM and Micro-CT

2019 ◽  
Vol 298 ◽  
pp. 155-160
Author(s):  
Bai Hong Jiang ◽  
Yi Yu ◽  
Lei Zhang ◽  
Shi Zhang Yu ◽  
Xiao Jin Gao
Keyword(s):  
Failure Mechanism ◽  
Linear Part ◽  
Tensile Fracture ◽  
In Situ Observation ◽  
Displacement Curve ◽  
Micro Ct ◽  
Pull Out ◽  
Load Displacement ◽  
Sic Composites

In order to better understand the failure mechanism of C/SiC composites, the tensile behavior of notched C/SiC composites was investigated by the in-situ scanning electron microscopy (SEM) and the micro-CT technique. Surface morphologies of the C/SiC sample during tensile loading were in-situ observed by SEM, while the three-dimensional microscopic images of the C/SiC sample before loading and after failure were obtained by micro-CT. The results showed that no cracks formed in the initial elastic stage corresponding to the linear part of the load-displacement curve. However, corresponding to the following non-linear part of the load-displacement curve, matrix crack initiation, fiber pull-out, crack propagation and deflection appeared consecutively in the notched region of the sample. What’s more, different crack growth paths existed in different directions of the sample during tensile failure. In general, approximately flat fracture formed in the plying direction and serrated or stepped fracture were observed in the needling direction. It indicated that the in-situ observation method combining SEM and micro-CT can obtain the micro-structure images of the material in different states, which is helpful to analyze the fracture failure mechanism of composites.

Research in Model Testing Pier-Foundation Hysteretic Property in Passenger Dedicated Line

2010 ◽  
Vol 37-38 ◽  
pp. 949-952
Author(s):  
Ming Bo Ding ◽  
Xing Chong Chen
Keyword(s):  
Cyclic Loading ◽  
Failure Mechanism ◽  
Constitutive Relation ◽  
Model Testing ◽  
Static Method ◽  
Test Model ◽  
Plastic Energy ◽  
Hysteretic Property ◽  
Testing Method ◽  
Energy Dissipated

The hysteretic and skeleton curves of load-displacement relation in pier top were got through the model-testing method of pile-soil interaction. The test model of pier was analyzed through static method-pushover. The complexity of subsoil property and constitutive relation of subsoil under reversal cyclic loading was considered. The model characteristics of energy dissipated, hysteretic property, ductility, failure mechanism and plastic energy of the pier under the horizontal reversal cyclic loading were researched.

Bond-Slip Numerical Simulation of Concrete and Gypsum Board

2011 ◽  
Vol 255-260 ◽  
pp. 3133-3136
Author(s):  
Quan Bin Zhao ◽  
Xin Liang Jiang
Keyword(s):  
Numerical Simulation ◽  
Constitutive Relation ◽  
Simulation Analysis ◽  
Experimental Results ◽  
Gypsum Board ◽  
Bond Slip ◽  
Pull Out ◽  
Simulation Results ◽  
Research Situation ◽  
Good Agreement

The characteristics and research situation of bond-slip performance at the inter face of concrete and other materials are introduced, and the bond-slip constitutive relation models are summarized at the same time. Through the load-slip curves obtained from the pull-out experiment of CFFP, the proposed bond-slip constitutive relation models are presenting, including the simple one. With the numerical simulation analysis of CFFP is carried out by the use of the proposed constitutive relation, while the numerical simulation results are in good agreement with the experimental results conducted before, which is feasible and can be applied to further research on CFFP.

scholarly journals Experimental Study of the Failure Mechanism of the Anchorage Interface under Different Surrounding Rock Strengths and Ambient Temperatures

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Xiaohu Liu ◽  
Zhishu Yao ◽  
Weipei Xue ◽  
Xuesong Wang ◽  
Xianwen Huang
Keyword(s):  
Energy Consumption ◽  
Failure Mechanism ◽  
Failure Modes ◽  
Rock Strength ◽  
Axial Stress ◽  
Surrounding Rock ◽  
Slip Mode ◽  
Pull Out ◽  
Axial Forces ◽  
Consumption Value

In order to study the anchoring instability mechanism of surrounding rock in deep roadway, the failure mechanism of the bolt-anchoring agent interface was studied by simulating different strength rock mass and ground temperature environment, using C20, C40, and C60 strength concrete and steel pipe to simulate different surrounding rock strength environments. Indoor pull-out tests were carried out to study the pull-out load displacement relationship, ultimate pull-out force, residual anchoring force, the distribution law of axial stress and tangential stress along the bar, and the energy consumption value of drawing failure at 20, 50, and 70°C. The test results show that, with the decrease of surrounding rock strength or the increase of ambient temperature, the pull-out force, residual anchoring force, and energy consumption value of anchorage interface gradually decrease; under different axial forces, the axial force distribution of the rod body decreases exponentially from the anchoring end to the opposite end; and the shear stress transfers to the deep part of the anchor body with the increase of the load. According to the failure phenomenon of the specimen, the failure modes of the bolt bolt-anchorage agent interface can be divided into shear slip mode and shear expansion slip mode. The shear expansion slip formula of anchorage interface is derived. Using high-strength and temperature-resistant resin anchoring agent for comparative test, the rationality of the mechanism analysis is proved, which provides more clear guidance for the construction of anchor support.

The failure mechanism and the pull-out strength of a bond-type anchor near a free edge

1998 ◽  
Vol 28 (1-4) ◽  
pp. 113-122 ◽  
Author(s):  
Makoto Obata ◽  
Michio Inoue ◽  
Yoshiaki Goto
Keyword(s):  
Failure Mechanism ◽  
Free Edge ◽  
Bond Type ◽  
Pull Out ◽  
Pull Out Strength

Research of Bond-Slip Constitutive Relation Model between Fiber Gypsum Board and Concrete Materials

2012 ◽  
Vol 485 ◽  
pp. 584-587
Author(s):  
Quan Bin Zhao ◽  
Xin Liang Jiang
Keyword(s):  
Constitutive Relation ◽  
Gypsum Board ◽  
Bond Slip ◽  
Pull Out ◽  
Relation Model ◽  
Concrete Materials ◽  
Research Situation

How to establish the bond-slip constitutive relation model of concrete and gypsum board will be of great academic significance. Through the pull-out experiment of CFFP, the load-slip curves is obtained. The characteristics and research situation of bond-slip performance at the inter face of concrete and other materials are introduced, and the bond-slip constitutive relation models are summarized at the same time. By using the fitting operation, the proposed constitutive relation is put forward , which is feasible and can be applied to further research on CFFP.

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