scholarly journals Test results and strength estimation of R/C beams strengthened against flexural or shear failure by the use of SRP and CFRP

2012 ◽  
Vol 43 (3) ◽  
pp. 1117-1129 ◽  
Author(s):  
George J. Mitolidis ◽  
Thomas N. Salonikios ◽  
Andreas J. Kappos
Keyword(s):  
Shear Failure ◽  
Test Results

Experimental Study on the Structural Performance of Beam-Column Joints in Old Buildings without Designed Shear Reinforcement under Earthquake

2017 ◽  
Vol 902 ◽  
pp. 33-40
Author(s):  
Cong Thuat Dang ◽  
Ngoc Hieu Dinh
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Test Results ◽  
Shear Reinforcement ◽  
Reinforcing Bars ◽  
Reinforced Concrete Buildings ◽  
Concrete Buildings ◽  
Gravity Load ◽  
Load Beam

Old reinforced concrete buildings constructed around 1980’s in many developing countries have been designed against mainly gravity load. Beam-column joints in these buildings contain slightly or no shear reinforcement inside the panel zones due to the construction convenience, and are vulnerable to shear failure in beam-column joints under the action of earthquake loads, especially for the exterior beam-column joints. This experimental study aimed to investigate the seismic performance of five half-scale exterior beam-column joints simulating the joints in existing reinforced-concrete buildings with non-shear hoop details. The test results showed that the structural performances of the beam-column joints under earthquake including failure mode, load-drift ratio relationship, shear strain of the joints and energy dissipation are strongly affected by the amount of longitudinal reinforcing bars of beams.

Behaviors of Xiashu Loess in the Lower Reaches of China’s Yangtze River under Triaxial Compression and the Microscopic Explanations

2016 ◽  
Vol 858 ◽  
pp. 91-97
Author(s):  
Jun Hua Xiao ◽  
Wen Qi Zheng
Keyword(s):  
Mechanical Properties ◽  
Yangtze River ◽  
Shear Failure ◽  
Triaxial Compression ◽  
Processing Technique ◽  
Point Of View ◽  
Image Processing Technique ◽  
Test Results ◽  
Compression Tests ◽  
Triaxial Compression Tests

To investigate the macroscopic mechanical properties of undisturbed structural Xiashu loess in the lower reaches of China’s Yangtze River under triaxial compression, and obtain the intrinsic explanations for the macroscopic mechanical properties from the microscopic point of view, in laboratory, triaxial compression tests were carried out, microstructure images of sheared samples were collected by scanning electron microscope (SEM), and quantitative parameters of microstructure (mainly about particle or pore size, distribution, and alignment) were extracted by digital image processing technique. Based on the test results, the deviator stress-strain relationships of both undisturbed and remoulded Xiashu loess, the structural strength, and the microstructural evolution mechanism about the formation of shear failure zone of Xiashu loess under triaxial compression were analyzed.

scholarly journals Pullout Behavior of GFRP Anti-Floating Anchor Based on the FBG Sensor Technology

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Ming-yi Zhang ◽  
Zheng Kuang ◽  
Xiao-yu Bai ◽  
Xiao-yu Chen
Keyword(s):  
Axial Force ◽  
Shear Failure ◽  
Distribution Functions ◽  
Sensor Technology ◽  
Force Distribution ◽  
Test Results ◽  
Glass Fiber Reinforcement ◽  
Promising Solution ◽  
Service Conditions ◽  
Fbg Sensors

Building anti-floating anchors have been increasingly used in recent years, but conventional steel anchors under service conditions are easily subjected to chemical erosion. Glass fiber reinforcement polymer (GFRP) is a promising solution to this problem. In this study, field pullout tests were conducted on three full instrumented GFRP anti-floating anchors in weathered granite. Specifically, the GFRP anchors during pultrusion were innovatively embedded with bare fiber Bragg grating (FBG) sensors to monitor the axial force distribution along depth. It was found that the embedded FBG could reliably monitor the axial force distribution of GFRP anchors. The ultimate pullout force of a GFRP anchor with diameter of 28 mm and anchorage length of 5 m was up to 400 kN. The GFRP anchor yielded at 0.8 m underground. Force distribution and field photos at failure indicated shear failure occurred at the anchor/bolt interface at the end of the tests. The feasibility of the GFRP anti-floating anchor was also verified in civil engineering. Finally, an elastic mechanical model and Mindlin’s displacement solution are used to get distribution functions of axial force and shear stress along the depth, and the results accord with the test results.

Mechanical Properties of Adobe Masonry in Shear Test

2011 ◽  
Vol 71-78 ◽  
pp. 3691-3694
Author(s):  
Feng Wu ◽  
Gang Li ◽  
Jin Qing Jia ◽  
Hong Nan Li
Keyword(s):  
Shear Strength ◽  
Shear Failure ◽  
Small Towns ◽  
Test Results ◽  
Double Shear ◽  
Adobe Masonry ◽  
Force Displacement ◽  
Good Workability ◽  
Loading Procedure ◽  
Low Shear

There are many adobe buildings in small towns and villages of China, which have low shear strength of mud in joints and suffer great damages in big earthquakes. Mud with three different proportions of soil and sand are used in adobe masonry to discuss shear behavior and strength in this paper. Adobe samples in tests were laid by mud with clay-silt soil: construction medium sand at ratios of 1:0.8, 1:1.0 and 1:1.2 respectively, and adobe brick at ratio of 1:1.0 which has good workability. Short straws are mixed into mud and brick at 0.5% by weight. By monotonous loading procedure parallel to bed joint, two bed joints in prisms behave double shear failure in sequence. Meanwhile shear strengths and force-displacement curves are also obtained. Fitting equation for adobe shear strength is calculated, and the calculated results are agree with test results well. Shear failure of adobe masonry behaves brittle from force-displacement curves.

The Nature of Chip Formation in Orthogonal Machining

1984 ◽  
Vol 106 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Daeyong Lee
Keyword(s):  
Shear Failure ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Test Results ◽  
Mechanical Instability ◽  
Specific Level ◽  
Orthogonal Machining ◽  
Analysis Technique ◽  
Machining Test ◽  
Hardening Coefficient

Orthogonal machining experiments were conducted at the cutting speed of 8.5 × 10−2 cm/s with 6061-T6 aluminum, 4340 steel and Ti-6Al-4V titanium to measure strain distributions in the deformed chip using a grid analysis technique. While the aluminum alloy with low strength and the steel with high strain hardening coefficient displayed large uniform strains with a continuous chip morphology, the titanium alloy exhibited highly nonuniform strain distributions within segmented chips. Some of these observations as well as published machining test results could be rationalized on the basis of a shear failure criterion where a specific level of critical shear strain might be estimated on the basis of a thermal-mechanical instability analysis.

Experimental Study on Interlaminar Shear Properties of T300/BMI Composite Laminates

2013 ◽  
Vol 718-720 ◽  
pp. 157-161
Author(s):  
Zong Hong Xie ◽  
Hai Han Liu ◽  
Jian Zhao ◽  
Jun Feng Sun ◽  
Fei Peng ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Shear Test ◽  
Failure Modes ◽  
Shear Failure ◽  
Test Method ◽  
Test Results ◽  
Shear Properties ◽  
Test Fixture ◽  
Iosipescu Shear Test ◽  
Interlaminar Shear

A modified test fixture to measure the shear properties of composite laminates was designed and manufactured based upon Iosipescu shear test method. Tests on interlaminar shear propertis of T300/BMI composite laminates were conducted according to ASTM D 5379 test standard. Interlaminar shear stress/strain curves and shear failure modes were obtained. The test results showed that the modified shear test fixture and test method were effective in measuring the shear properties of composite laminates.

Analysis of Bending Loads on Bamboo-Balsa and Bamboo-Polypropylene Honeycomb Composite Sandwiches

2015 ◽  
Vol 1125 ◽  
pp. 94-99 ◽  
Author(s):  
Aldyandra Hami Seno ◽  
Eko Koswara ◽  
Hendri Syamsudin ◽  
Djarot Widagdo
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Models ◽  
Future Research ◽  
Test Results ◽  
Bending Tests ◽  
Bending Loads ◽  
Bending Behavior ◽  
Honeycomb Cores ◽  
Load Deflection Curve

This research was done to evaluate the bending behavior (load-deflection curve and failuremode) of sandwich structures using Tali Bamboo strips as sandwich skin material. Bending tests wereconducted on sandwich specimens with end grain balsa (3-point bending) and polypropylene (PP)honeycomb cores (4-point bending) to evaluate their bending behavior. From the test results,analytical and numerical models were developed to simulate the observed bending behavior. Themodels are able to simulate the pre-failure bending behavior and failure modes (core shear failure) ofthe specimens. It is also shown that for thin (length/thickness > 20) sandwiches the models are moreaccurate since shear effects are less prominent. With the obtained models a predictive comparison isdone between the PP and balsa cored specimens since the testing configuration for each type wasdifferent. The analysis results show that balsa cored specimens are able to withstand higher transversebending loads due to the higher shear strength of the balsa core. These prediction results are to beproven by specimen testing which is the subject of future research.

Size Effect of Uniaxial Compressive Strength of Limestone

2012 ◽  
Vol 229-231 ◽  
pp. 233-238 ◽  
Author(s):  
Ze Hui Chen ◽  
Chang Wu Liu ◽  
Ji Wei Deng
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Size Effect ◽  
Shear Failure ◽  
Testing Machine ◽  
Peak Strain ◽  
Test Results ◽  
Effect Model ◽  
Splitting Failure ◽  
Uniaxial Compressive Test

Using the MTS testing machine, the uniaxial compressive test of varisized da-qing limestones were undertaken, and the effect of dimensions about compressive strength, peak strain, elastic modulus and destructional forms of rock specimens were studied. It demonstrates that along with the increase of length-diameter ratio, peak strain and compressive strength turn smaller, elastic modulus gradually increases, the destruction of rock samples have a transformation from splitting failure to shear failure. Combined with the test results, Obert L model and Yang Shengqi model, the two size-effect models with extensive applications are analyzed and contrasted. And the conclusion is drawn that Obert L model has a relatively broad applicability, while Yang Shengqi model has a stronger Targeting and higher accuracy. Thus based on the Yang Shengqi model, the size-effect model of da-qing limestone is put forward, and the result indicates that this model corresponds well with the test results, having certain practical value.

scholarly journals X-Ray Microtomography (μCT) as a Useful Tool for Visualization and Interpretation of Shear Strength Test Results

2015 ◽  
Vol 36 (4) ◽  
pp. 47-55 ◽  
Author(s):  
Damian Stefaniuk ◽  
Matylda Tankiewicz ◽  
Joanna Stróżyk
Keyword(s):  
Shear Strength ◽  
Shear Failure ◽  
Triaxial Compression ◽  
Soil Testing ◽  
Geometrical Parameters ◽  
Clayey Soils ◽  
Test Results ◽  
Strength Parameters ◽  
X Ray ◽  
Method Of Evaluation

Abstract The paper demonstrates the applicability of X-ray microtomography (ìCT) to analysis of the results of shear strength examinations of clayey soils. The method of X-ray three-dimensional imaging offers new possibilities in soil testing. The work focuses on a non-destructive method of evaluation of specimen quality used in shear tests and mechanical behavior of soil. The paper presents the results of examination of 4 selected clayey soils. Specimens prepared for the triaxial test have been scanned using ìCT before and after the triaxial compression tests. The shear strength parameters of the soils have been estimated. Changes in soil structure caused by compression and shear failure have been presented as visualizations of the samples tested. This allowed for improved interpretation and evaluation of soil strength parameters and recognition of pre-existing fissures and the exact mode of failure. Basic geometrical parameters have been determined for selected cross-sections of specimens after failure. The test results indicate the utility of the method applied in soil testing.

scholarly journals Characterization and performance of elementary hemp fibres: Factors influencing tensile strength

BioResources ◽  
2010 ◽  
Vol 5 (4) ◽  
pp. 2307-2322 ◽  
Author(s):  
Mizi Fan
Keyword(s):  
Tensile Strength ◽  
Shear Failure ◽  
Fibre Length ◽  
Test Results ◽  
Test Pieces ◽  
Hemp Fibres ◽  
Single Fibres ◽  
Strain Stress ◽  
And Performance ◽  
Optimized Treatment

This paper presents the outcomes from an extensive investigation on the structure and geometry of single hemp fibres, as well as configurations and related tensile strength (TS) of hemp fibres, with the aid of field emission scanning and optical microscopy. The results showed that 1) the TS increased with the decrease of the diameter of individual test pieces, due possibly to the stacks of multiple single fibres within the test pieces; 2) shear failure between single fibres in a test pieces played a significant role in the test results; 3) the TS was closely related to the number of both the inherent joints along the fibre length and single fibres contained in the test pieces; 4) the splits along the length and width of hemp fibres may complicate the test results, and 5) the optimized treatment prior to decortications may double the TS of hemp fibres compared to a normal retting processing. Reliable TS of single hemp fibres have been derived by a power regression, and the predicted TS were verified with an excellent agreement with experimentally tested results. The tensile strain-stress plot was found to be linear for all hemp test pieces, showing that the behaviour of single hemp fibres obeys Hooke’s law.

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