scholarly journals Stress Transfer Properties and Displacement Difference of GFRP Antifloating Anchor

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Xiaoyu Bai ◽  
Xueying Liu ◽  
Mingyi Zhang ◽  
Yonghong Wang ◽  
Zheng Kuang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Shear Stress ◽  
Axial Stress ◽  
Field Research ◽  
Distribution Model ◽  
Mechanical Transmission ◽  
Anchorage Length ◽  
Pull Out ◽  
Peak Shear Stress ◽  
Deformation Properties

Glass fiber reinforced polymer (GFRP) antifloating anchors are widely used in reinforcing underground structures. Despite the outstanding application advances of GFRP anchors in the antifloating field, research on the mechanical transmission and deformation properties of the anchor rod and anchorage body is still scarce. This paper introduces pull-out experiments of GFRP antifloating anchors based on the FBG sensor strings technology. The experimental data demonstrates that the distribution curve of the axial stress shows a reversed-S shape, and the shear stress distribution presents the law of increasing first and then decreasing from the position of peak shear stress. The rod-anchorage body displacement difference curves of the anchors with an anchorage length that is closer to the critical anchorage length are smoother than those of the anchors with a larger length difference from the critical anchorage length. Finally, a simplified distribution model of the shear stress is applied for predicting the rod-anchorage body displacement difference, and the experimental data of the anchors with a rod slip failure is more applicable for this model than that of the anchors with a rod rupture failure.

Study on the Effect of Bond-Anchoring Factor on Bond Behavior between Deformed Bar and Shale Ceramic Concrete

2011 ◽  
Vol 403-408 ◽  
pp. 444-448
Author(s):  
Wei Jun Yang ◽  
Jie Yu ◽  
Yan Wang
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Anchorage Length ◽  
Bond Behavior ◽  
Pull Out ◽  
Practical Project ◽  
Deformed Bar

In this paper, the effect of bond-anchoring factor on bond behavior between deformed bar and shale ceramic concrete was analyzed by four groups of pull-out tests with different anchorage length. And three reinforced concrete pull-out tests used for comparative analysis were prepared at the same time. We obtained a series of experimental data and based on these data .A more accurate formula was summed up. This formula has a high value in guiding the practical project to choose the anchorage length.

Experimental and Numerical Analysis on the Bonding Performance of GFRP Bolts

2015 ◽  
Vol 777 ◽  
pp. 166-172
Author(s):  
Ya Chuan Kuang ◽  
Lian Wen Ou ◽  
Jin Xing Hu
Keyword(s):  
Numerical Analysis ◽  
Friction Angle ◽  
Surface Shape ◽  
Anchorage Length ◽  
Rock Stability ◽  
Bonding Performance ◽  
Ansys Analysis ◽  
Pull Out ◽  
Peak Shear Stress ◽  
Bolt Diameter

By pull-out tests between GFRP bolts and concrete, the influence of the diameter and surface shape of GFRP bolts on the bonding performance was studied. By ANSYS analysis, the effects of anchorage length, diameter, geotechnical parameters and prestress on the bonding performance were studied. The experimental and numerical analysis results show that: with the increase of bolt diameter, the bonding strength of bolts decrease and the slippages increase. The bigger the parameters of rock-soil like modulus of elasticity, cohesion strength and internal friction angle are, the better is the bond behavior and the smaller is the slippage. The prestress plays an important role in the rock stability and the restriction of deformation. With the enhancement of the prestress of bolts, the peak shear stress increases but the effective anchorage length nearly stays the same.

scholarly journals Bolt Pull-Out Tests of Anchorage Body under Different Loading Rates

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Tong-bin Zhao ◽  
Wei-yao Guo ◽  
Yan-chun Yin ◽  
Yun-liang Tan
Keyword(s):  
Shear Stress ◽  
Axial Force ◽  
Interfacial Shear Stress ◽  
Interfacial Shear ◽  
Interfacial Stress ◽  
Particle Flow Code ◽  
Mechanical Transmission ◽  
Loading Rates ◽  
Pull Out ◽  
Distribution Rule

Based on the force analysis and mechanical transmission mechanism of grouting bolts, the self-developed test apparatus for interfacial mechanics is used to study the distribution rule of axial force and interfacial stress of bolts in anchorage body. At the same time, pull-out tests of anchorage body are simulated with the particle flow code softwarePFC2D, and stress distribution and failure patters are researched under different loading rates. The results show that the distribution of axial force and interfacial shear stress is nonuniform along the anchorage section: axial force decreases, shear force increases first and then decreases, and the maximum value of both of them is closed to the pull-out side; with the increase of loading rates, both of axial force and interfacial shear stress show a trend of increase in the upper anchorage section but changes are not obvious in the lower anchorage section, which causes serious stress concentration; failure strength of pull-out and loading rates show a linear correlation; according to loading rates’ impact on the anchoring effect, the loading rates’ scope can be divided into soft scope (v<10 mm/s), moderate scope (10 mm/s <v< 100 mm/s), and strong scope (v>100 mm/s).

Micromechanical Analysis of Single-Fiber Pull-Out Test of Fiber-Reinforced Viscoelastic Matrix Composites

2011 ◽  
Vol 399-401 ◽  
pp. 556-560 ◽  
Author(s):  
Da Sheng Zhu ◽  
Bo Qin Gu
Keyword(s):  
Shear Stress ◽  
Volume Fraction ◽  
Axial Stress ◽  
Single Fiber ◽  
Axial Distance ◽  
Matrix Composites ◽  
Stress Distributions ◽  
Fiber Reinforced ◽  
Viscoelastic Matrix ◽  
Pull Out

A micromechanical model for single-fiber pull-out test of fiber-reinforced viscoelastic matrix composites is established. It includes fiber, interphase and viscoelastic matrix. The formulas to calculate the fiber axial stress, the interphase shear stress, and the matrix axial and shear stress are obtained. Moreover, for Kevlar aramid fiber reinforced viscoelastic matrix composites, the influences of the interphase thickness, the fiber embedded length and volume fraction on the stress distributions of fiber and interphase is studied. Some analysis results show that, with the increase of normalized fiber axial distance, the fiber axial stress increases monotonically, but the interphase shear stress decreases. The stress distributions of fiber and interphase change with the variation of the interphase thickness, the fiber embedded length and volume fraction.

scholarly journals Assessing the Difference in Measuring Bolt Stress: A Comparison of Two Optical Fiber Sensing Techniques

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jing Chai ◽  
Qi Liu ◽  
Jinxuan Liu ◽  
Guihua Zhang ◽  
Dingding Zhang ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Axial Stress ◽  
Setting Time ◽  
Time Domain Analysis ◽  
Load Level ◽  
Field Application ◽  
Mechanical Transmission ◽  
Pull Out ◽  
Relative Standard

Monitoring the load level of the rock bolts is of great importance for assessing risk. Based on the mechanical transmission mechanism of grouting bolts, the bolt pull-out test was carried out in lab. The performance of the bolt under pull-out loading was measured using the pulse-pre-pump Brillouin optical time domain analysis (PPP-BOTDA) and fiber Bragg grating (FBG) sensing technologies. The distribution characteristic of axial stress along the bolt was analysed in combination with the measurements obtained by the two sensing technologies. The relative standard deviation for repeatability errors in the determination and the setting time of resin grout was investigated. The results show that the distribution of axial stress is nonuniform along the anchorage section. The maximum value of axial stress on the bolt is closed to the pull-out side. The relative standard deviation for repeatability errors obtained by PPP-BOTDA is less than that obtained by FBG. The comparison of the measurements obtained by the two methods indicates that when the drawing force is greater than 20 kN and the axial stress is more than 10 kN, the two methods have better consistency. In the field application, it is necessary to estimate the deformation of matrix, leaving at least 500 minutes for resin bond to work.

Fatigue Tolerance of Aged Asphalt Binders Modified with Softeners

2021 ◽  
pp. 036119812110255
Author(s):  
Javier J. García Mainieri ◽  
Punit Singhvi ◽  
Hasan Ozer ◽  
Brajendra K. Sharma ◽  
Imad L. Al-Qadi
Keyword(s):  
Shear Stress ◽  
Heavy Traffic ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Data Interpretation ◽  
Complex Stress ◽  
Current Data ◽  
Asphalt Binders ◽  
Failure Patterns ◽  
Peak Shear Stress

Fatigue cracking caused by repeated heavy traffic loading is a critical distress in asphalt concrete pavements and is significantly affected by the selected binder. In recent years, the growing use of recycled asphalt materials has increased the need for the production of softer asphalt binder. Various modifiers/additives are marketed to adjust the grade and/or enhance the binder performance at high and low temperatures. The modifiers are expected to alter the rheological and chemical characteristics of binders and, therefore, their performance. In this study, the damage characteristics of modified and unmodified binders, at standard long-term and extended aging conditions, were tested using the linear amplitude sweep (LAS) test. Current data-interpretation methods for LAS measurements (including AASHTO TP 101-12, T 391-20, and recent literature) showed inconsistent results for modified binders. An alternative method to interpret LAS results was developed in this study. The method considers the data until peak shear-stress is reached because complex stress states and failure patterns are observed in the specimens after that point. The proposed parameter (Δ| G*|peak τ) quantifies the reduction in complex shear modulus measured at the peak shear-stress. The parameter successfully captures the effect of aging and modification of binders.

Parametric study of multi-story, perforated, partially grouted masonry walls subjected to in-plane cyclic actions

2020 ◽  
Author(s):  
Klaus Medeiros ◽  
Kyle Chavez ◽  
Fernando S. Fonseca ◽  
Guilherme Parsekian ◽  
Nigel G. Shrive
Keyword(s):  
Experimental Data ◽  
Shear Strength ◽  
Aspect Ratio ◽  
Load Capacity ◽  
Axial Stress ◽  
Reinforcement Ratio ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Initial Stiffness ◽  
Vertical Reinforcement

Finite element models were developed to assess the influence of several parameters on the load capacity, deflection, and initial stiffness of multi-story, partially grouted masonry walls with openings. The base model was validated with experimental data from three walls. The analyses indicated that the load capacity of masonry walls was considerably sensitive to the ungrouted and grouted masonry strengths and mortar shear strength; moderately sensitive to the vertical reinforcement ratio and aspect ratio; slightly sensitive to the axial stress; and almost insensitive to the opening size, reinforcement spacing, and horizontal reinforcement ratio. The deflection of the walls had well-defined correlations with the masonry strength, vertical reinforcement, axial stress and aspect ratio. The initial stiffness was especially sensitive to the axial stress and the aspect ratio, but weakly correlated with the opening size, and the spacing and size of the reinforcement.

Experimental Study on Critical Shear Stress of Cohesive Soils and Soil Mixtures

2021 ◽  
Vol 64 (2) ◽  
pp. 587-600
Author(s):  
Xiaojing Gao ◽  
Qiusheng Wang ◽  
Chongbang Xu ◽  
Ruilin Su
Keyword(s):  
Experimental Data ◽  
Shear Stress ◽  
Critical Shear Stress ◽  
Cohesive Soil ◽  
Future Research ◽  
Cohesive Soils ◽  
List Type ◽  
Soil Mixture ◽  
Linear Relationships ◽  
Soil Mixtures

HighlightsErosion tests were performed to study the critical shear stress of cohesive soils and soil mixtures.Linear relationships were observed between critical shear stress and cohesion of cohesive soils.Mixture critical shear stress relates to noncohesive particle size and cohesive soil erodibility.A formula for calculating the critical shear stress of soil mixtures is proposed and verified.Abstract. The incipient motion of soil is an important engineering property that impacts reservoir sedimentation, stable channel design, river bed degradation, and dam breach. Due to numerous factors influencing the erodibility parameters, the study of critical shear stress (tc) of cohesive soils and soil mixtures is still far from mature. In this study, erosion experiments were conducted to investigate the influence of soil properties on the tc of remolded cohesive soils and cohesive and noncohesive soil mixtures with mud contents varying from 0% to 100% using an erosion function apparatus (EFA). For cohesive soils, direct linear relationships were observed between tc and cohesion (c). The critical shear stress for soil mixture (tcm) erosion increased monotonically with an increase in mud content (pm). The median diameter of noncohesive soil (Ds), the void ratio (e), and the organic content of cohesive soil also influenced tcm. A formula for calculating tcm considering the effect of pm and the tc of noncohesive soil and pure mud was developed. The proposed formula was validated using experimental data from the present and previous research, and it can reproduce the variation of tcm for reconstituted soil mixtures. To use the proposed formula to predict the tcm for artificial engineering problems, experimental erosion tests should be performed. Future research should further test the proposed formula based on additional experimental data. Keywords: Cohesive and noncohesive soil mixture, Critical shear stress, Erodibility, Mud content, Soil property.

scholarly journals Testing the influence of a sand mica mixture on basin fill in extension and inversion experiments

2015 ◽  
Vol 87 (1) ◽  
pp. 51-62 ◽  
Author(s):  
CAROLINE J.S. GOMES ◽  
TAYNARA D'ANGELO ◽  
GISELA M.S. ALMEIDA
Keyword(s):  
Shear Stress ◽  
Physical Models ◽  
Normal Faults ◽  
Striking Difference ◽  
Fault Propagation ◽  
Peak Shear Stress ◽  
Internal Deformation ◽  
Deformation Patterns ◽  
And Inversion ◽  
Basin Fill

We compare the deformation patterns produced by sand and a sand mica mixture (14:1 ratio of sand to mica by weight) while simulating basin fill in extension and inversion models to analyze the potential of the sand mica mixture for applications that require a strong elasto-frictional plastic analogue material in physical models. Sand and the sand mica mixture have nearly equal angles of internal friction, but the sand mica mixture deforms at a significantly lower level of peak shear stress. In extension, the sand mica mixture basin fill experiments show fewer normal faults. During inversion, the most striking difference between the sand and the sand mica mixture basin fill experiments is related to the internal deformation in fault-propagation folds, which increases with an increase in the basal friction. We conclude that our strongly elasto-frictional plastic sand mica mixture may be used to simulate folds in experiments that focus on mild inversion in the brittle crust.

3-D Simulation for Blood Flow and Artery Compression in Asymmetric Stenotic Arteries With Axial Stretch

2001 ◽  
Author(s):  
Dalin Tang ◽  
Chun Yang ◽  
Shunnichi Kobayashi
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Shear Stress ◽  
Wall Stress ◽  
Small Strain ◽  
Rigid Wall ◽  
Severe Stenosis ◽  
Physiological Conditions ◽  
Oscillating Shear Stress ◽  
Stenotic Arteries

Abstract There has been increasing evidence that severe stenosis may cause artery compression and plaque cap rupture leading to heart attack and stroke. The physiological conditions under which that may occur and mechanisms involved are not well understood. It has been known that severe stenosis causes critical flow and wall mechanical conditions such as flow limitation, flow separation, low and oscillating shear stress distal to the stenosis, high shear stress and low or even negative flow pressure at the throat of stenosis, artery compression or even collapse. Those conditions are related to limitation of blood supply, intimal thickening and thrombosis formation, endothelism damage, platelet activation and aggregation, plaque cap rupture (for review, see [1,2]). Due to the complexity of the problem and lack of experimental data for mechanical properties of arteries under both expansion and compression, previous models were limited primarily to flow behaviors and with various limitations (axisymmetry, rigid wall, small strain, small pressure gradient). In this paper, experimental data for artery mechanical properties under physiological conditions were measured and a 3-d computational model is introduced to investigate flow behaviors and wall stress and strain distributions with fluid-structure interactions to better understand the mechanism involved in artery compression and plaque cap rupture.

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