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.

Damage Detection with FBG Sensors for Pre-Stress Concrete Girders

2017 ◽  
Vol 737 ◽  
pp. 454-458 ◽  
Author(s):  
Seong Cheol Lee ◽  
Kyung Joon Shin ◽  
Jae Min Kim ◽  
Hwan Woo Lee
Keyword(s):  
Prestressed Concrete ◽  
Shear Failure ◽  
Experimental Program ◽  
Test Results ◽  
Strain Variation ◽  
Concrete Members ◽  
Concrete Girders ◽  
Drastic Increase ◽  
Fbg Sensors ◽  
Tendon Strain

In this paper, possibility to detect damage on post-tensioned concrete girders was investigated through an experimental program with 6 m long specimens containing smart tendons where FBG (Fiber Bragg Grating) sensors were embedded. Total six specimens were fabricated and tested, and test variables were prestressing tendon’s profile and web thickness. All the specimens were subjected to 3-points loading, and they exhibited shear failure. Through the test, it was observed that tendon strains were successfully measured through FBG sensors regardless of the test variables. It was also observed that tendon strains within the pure span significantly increased while ones nearby the anchors beyond the pure span were constant. When the specimen was cracked, FBG sensors nearby cracks showed relatively drastic increase on tendon strain. Since strain variation along tendons cannot be detected by conventional equipment such as a load-cell, the test results indicated that actual tendon strains can be easily measured with FBG sensors. These results showed that FBG sensors can be useful to check whether prestressed concrete members were significantly damaged. In addition, it is expected that FBG sensors can be helpful on more reasonable maintenance of PSC girders.

Design of combined brake system for light weight scooters

2021 ◽  
pp. 095440702110240
Author(s):  
Yuan-Ting Lin ◽  
Chyuan-Yow Tseng ◽  
Jao-Hwa Kuang ◽  
Yeong-Maw Hwang
Keyword(s):  
Ride Comfort ◽  
Brake System ◽  
Force Distribution ◽  
Test Results ◽  
Systematic Method ◽  
Braking Performance ◽  
Evaluation Indexes ◽  
Low Costs ◽  
Braking Force ◽  
Good Agreement

The combined brake system (CBS) is a mechanism that links the front and rear brakes for scooters. For two-wheeled scooters, a CBS with appropriate braking force distribution can reduce the risk of crashing accidents due to insufficient driving proficiency. The design of the braking force distribution for a CBS is challenging to the designer because it has to fulfill many requirements such as braking performance, ride comfort, reliability, and low costs. This paper proposes a systematic method to optimize the parameters of CBS. The evaluation indexes for the design are first discussed. The steps to determine the critical parameter to meet the indexes and a method to predict braking performance are developed. Finally, driving tests are carried out to verify the effectiveness of the proposed method. Experimental results showed that the deceleration of the tested scooter equipped with the designed CBS achieves an average mean fully developed deceleration (MFDD) of 5.246 m/s2, higher than the homologation requirement. Furthermore, the proposed method’s prediction of braking performance is in good agreement with the test results, with errors <1%.

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.

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.

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

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.

The Application of Fiber Optic Test Technology in Deformation Monitoring of Highway Corrugated Steel Pipe Culvert

2011 ◽  
Vol 255-260 ◽  
pp. 1007-1011
Author(s):  
Fan Zhang ◽  
Ping Fang ◽  
Hai Tao Qian
Keyword(s):  
Term Structure ◽  
Fiber Optic ◽  
Steel Structure ◽  
Deformation Monitoring ◽  
Steel Pipe ◽  
Test Results ◽  
Test Technology ◽  
Testing Technology ◽  
Fbg Sensors ◽  
Test Points

Compared to the traditional testing technology, the fiber bragg grating(FBG) test technology has many unique advantages and is suitable for the long-term structure health monitoring. By testing the stress and strain conditions of the corrugated steel pipe culverts under different fill heights with FBG sensors set in the inner and outer of the culverts, the mechanical properties of the steel pipe culverts could be obtained. The field fiber optic test results show that the FBG sensors can be used in the structures under complex engineering conditions. When the fill height is added, the FBG test results will change significantly in real-time, and the strain values of all test points on the culvert will change with the increase of the fill height, particularly in the top and bottom test points of the culvert. So the Fiber optic test technology can adapt to the testing requirements of the corrugated steel structure, and can provide a basis for the design of the corrugated steel pipe.

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