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

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 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.

Progressive failure mechanism in granular materials subjected to an alternant active and passive trapdoor

2021 ◽  
Vol 28 ◽  
pp. 100529
Author(s):  
Yu Zhao ◽  
Quanmei Gong ◽  
Yaojie Wu ◽  
Zhiyao Tian ◽  
Shunhua Zhou ◽  
...  
Keyword(s):  
Granular Materials ◽  
Failure Mechanism ◽  
Progressive Failure

scholarly journals Design of plate and screw anchors in dense sand: failure mechanism, capacity and deformation

2019 ◽  
Vol 92 ◽  
pp. 16010
Author(s):  
Benjamin Cerfontaine ◽  
Jonathan Knappett ◽  
Michael Brown ◽  
Aaron Bradshaw
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Failure Mechanism ◽  
Progressive Failure ◽  
Vertical Direction ◽  
Shear Plane ◽  
Design Methods ◽  
Embedment Depth ◽  
Limiting State ◽  
Dense Sand

Plate and screw anchors provide a significant uplift capacity and have multiple applications in both onshore and offshore geotechnical engineering. Uplift design methods are mostly based on semi-empirical approaches assuming a failure mechanism, a normal and a shear stress distribution at failure and empirical factors back-calculated against experimental data. However, these design methods are shown to under- or overpredict most of the existing larger scale experimental tests. Numerical FE simulations are undertaken to provide new insight into the failure mechanism and stress distribution which should be considered in anchor design in dense sand. Results show that a conical shallow wedge whose inclination to the vertical direction is equal to the dilation angle is a good approximation of the failure mechanism in sand. This shallow mechanism has been observed in each case for relative embedment ratios (depth/diameter) ranging from 1 to 9. However, the stress distribution varies non-linearly with depth, due to the soil deformability and progressive failure. A sharp peak of normal and shear stress can be identified close to the anchor edge, before a gradual decrease with increasing distance along the shear plane. The peak stress magnitude increases almost linearly with embedment depth at larger relative embedment ratios. Although further research is necessary, these results lay the basis for the development of a new generation of design criteria for determining anchor capacity at the ultimate limiting state.

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 A Trans-Scale Young’ Modulus Calculation Model of ITZ Based on Void Shape Randomness and Calcium Hydroxide Enrichment

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Junqing Liu ◽  
Fan Zuo ◽  
Chao Liu
Keyword(s):  
Calcium Hydroxide ◽  
Random Distribution ◽  
Young Modulus ◽  
Theoretical Models ◽  
Calculation Model ◽  
Interfacial Transition Zone ◽  
Morphological Parameters ◽  
Proposed Model ◽  
Three Phase ◽  
Void Shape

The randomness of void shape and enrichment of calcium hydroxide are significant in interfacial transition zone (ITZ) of concrete; however, current theoretical models of ITZ do not include these features. In this article, ITZ was regarded as a three-phase composite material, and the pore morphological parameters were defined according to the characteristics of microscopic pores, and the corresponding random distribution function was constructed. The calcium hydroxide enrichment factor was introduced, and a cross-scale ITZ Young’s modulus calculation model was established in combination with the Mori–Tanaka method. The reliability of the proposed model in this paper was verified through comparison to experimental results in a reference.

Dynamic response and failure mechanism of Ti-6AL-4V hi-lock bolts under combined tensile-shear loading

2019 ◽  
Vol 131 ◽  
pp. 140-151 ◽  
Author(s):  
Xiaochuan Liu ◽  
Xulong Xi ◽  
Chunyu Bai ◽  
Jialing Yang ◽  
Xianfeng Yang
Keyword(s):  
Dynamic Response ◽  
Failure Mechanism ◽  
Shear Loading ◽  
Tensile Shear

scholarly journals Failure Mechanism of a Coal-Rock Combined Body with Inclinations of Structural Planes and a Calculation Model for Impact Energy

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Yi-Chao Zhao ◽  
Ming-Shi Gao ◽  
Yong-Liang He ◽  
Dong Xu
Keyword(s):  
Mechanical Properties ◽  
Failure Mechanism ◽  
Impact Energy ◽  
Coal Mines ◽  
Calculation Model ◽  
Engineering Practice ◽  
Test Results ◽  
Failure Characteristics ◽  
Coal Rock ◽  
Rock Strata

A coal-rock (CR) combined body can be used to simulate structures of coal and rock strata, and its impact-induced failure characteristic conforms more close to engineering practice. Exploring the mechanical properties and impact energy in a CR combined body contributes to better predictions of rock bursts in coal mines. In the study, the mechanical properties of CR combined bodies with four different inclinations (0°, 15°, 30°, and 45°) of structural planes were measured, and also their failure mechanism was analysed. Based on the theory of particle mechanics, a calculation model for impact energy in a CR combined body with inclinations was established and then verified by using monitored acoustic emission (AE) data. The test results showed that inclination affected mechanical properties and failure characteristics of the CR combined body, i.e., the larger the inclination, the lower the strength and impact energy in the CR combined body and the lower the level of damage. The proposed calculation model for impact energy revealed the mechanical essence of energy accumulation and release of a CR combined body, providing a reference for investigating rock burst in coal mines.

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