scholarly journals Analysis of Bearing Strength of Post-Tensioning Anchorage Zone with Respect to Relative Bearing Area and Lateral Confinement Design

2021 ◽  
Vol 11 (18) ◽  
pp. 8386
Author(s):  
Jin-Kook Kim ◽  
Jun-Mo Yang
Keyword(s):  
Error Rate ◽  
Small Diameter ◽  
Average Error ◽  
Displacement Curve ◽  
Proportional Limit ◽  
Lateral Confinement ◽  
Bearing Strength ◽  
Bearing Plate ◽  
Load Displacement ◽  
Post Tensioning

This study aimed to evaluate the bearing strength of the post-tensioning anchorage zone with respect to the relative bearing area and lateral confinement design of spiral and stirrup rebars. Eleven specimens were fabricated and tested to fracture in accordance with EAD 160004-00-0301. Load-displacement curves and fracture modes were analyzed. Then, the conventional design equation for the bearing strength and previous findings on the relative bearing area was re-investigated in comparison with the test results. From the test, the representative findings are as follows: (1) A specimen with relatively small size and less lateral reinforcement is more likely to be affected by the wedge action of the anchorage device; however, a larger specimen is affected by both concrete crushing and/or spalling; (2) The behavior of the anchorage zone is markedly affected by the local behavior near the anchorage bearing plate, and the sectional efficiency is mostly determined by A/Ag; (3) For specimens with A/Ag = 9.52, the proportional limit of the load-displacement curve is determined by the yield of spiral rebar or fracture of the bearing plate, but the later part of the curve is determined by lateral confinement; (4) The maximum A/Ag that could produce 100% sectional efficiency is about 2.0 for the anchorage bearing plate used in the test; (5) For a fully confined specimen with a small-diameter spiral for minimum anchorage spacing, the stirrup rebar design mainly influences crack occurrence and patterns when the size of the specimen is equal to the minimum anchorage spacing; however, the area of the load-displacement curve after the proportional limit as well as crack occurrence and patterns are also influenced by stirrup rebar design when A/Ag is relatively large; (6) Finally, a revised design model is proposed to effectively estimate the ultimate bearing strength of the post-tensioning anchorage zone without respect to A/Ag. From the comparison of the design equations, it was concluded that the proposed equation provides a more reliable prediction with a 14.0% average error rate and 5.7% standard deviation of error rate.

scholarly journals Investigation on the behavior of rigid polyvinylchloride pipes subjected to uniaxial compression loads

2017 ◽  
Vol 23 (3) ◽  
pp. 145
Author(s):  
Abdullah Ali Nasser Alhamati ◽  
Abdul Halim Ghazali ◽  
Jamalodin Norzaie
Keyword(s):  
Uniaxial Compression ◽  
Small Diameter ◽  
Experimental Tests ◽  
Displacement Curve ◽  
Axial Loads ◽  
Pipe System ◽  
Euler Buckling ◽  
Specimen Height ◽  
Brick Element ◽  
Load Displacement

The objective of this research was to investigate the capability of rigid Polyvinylchloride (PVC-U) pipes to sustain axial loads. The behavior of PVC-U pipes specimens subjected to short-term uniaxial compression loads were experimentally investigated. Results of the load-displacement tests on pipes of different wall thickness, diameter, and specimen heights were recorded. The experimental test results show that the PVC-U pipes are capable of supporting loads greater than the required design load (3.4 kN). Increasing the pipe specimen height decreases the pipe strength for supporting the axial loads.  Euler buckling was observed in the pipe specimens with small diameter and long axial height. Furthermore, an attempt has been made to utilize the ANSYS finite element commercial package to model the pipe system using eight noded brick element and the results were compared with those obtained from the experimental tests. Good agreement was found between the two sets of results, within the elastic range of the load-displacement curve.

Bearing strength and failure analysis on the interference-fit double shear-lap pin-loaded composite

2016 ◽  
Vol 27 (2) ◽  
pp. 179-200 ◽  
Author(s):  
Peng Zou ◽  
Kaifu Zhang ◽  
Yuan Li ◽  
Ping Liu ◽  
Huanhuan Xie
Keyword(s):  
Composite Laminates ◽  
Composite Structures ◽  
Progressive Failure ◽  
Tensile Load ◽  
Failure Criteria ◽  
Displacement Curve ◽  
Progressive Damage ◽  
Interference Fit ◽  
Bearing Strength ◽  
Load Displacement

Interference-fit technology has a wide effect on the strength and fatigue life of composite structures. The damage around the hole may accelerate the structure failure. In this paper, a progressive damage model is developed to predict the response of interference-fit pin-loaded composite laminates during the installation and loading process with the ABAQUS subroutine user-define-field (USDFLD). The model takes contact at the pin–hole interface, the nonlinear shear stress–strain relationship and the property progressive damage into consideration. The loading procedure is separated into two parts: (a) installing the Hi-Lok pin. (b) Applying the tensile load. To predict progressive failure, the mixed failure criteria combining Hashin criteria and the maximum stress failure criteria, and the Camanho and Matthews degradation rules are conducted. The insertion load, stress and damage around the hole, load–displacement curve, and the bearing strength are predicted. A series of experiments have also been performed and the rationality of the model is testified. The parametric study is also made to analyze the effect of fit conditions on insertion load, damage, and load–displacement curve.

scholarly journals Study on the Strength Performance of Recycled Aggregate Concrete with Different Ages under Direct Shearing

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2312
Author(s):  
Xin Liang ◽  
Fang Yan ◽  
Yuliang Chen ◽  
Huiqin Wu ◽  
Peihuan Ye ◽  
...  
Keyword(s):  
Shear Strength ◽  
Shear Force ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Displacement Curve ◽  
Direct Shear ◽  
Replacement Ratio ◽  
Aggregate Concrete ◽  
Concrete Failure ◽  
Load Displacement

In order to study the mechanical properties of recycled aggregate concrete (RAC) at different ages, 264 standard cubes were designed to test its direct shear strength and cube compressive strength while considering the parameters of age and recycled aggregate replacement ratio. The failure pattern and load–displacement curve of specimens at direct shearing were obtained; the direct shear strength and residual shear strength were extracted from the load–displacement curves. Experimental results indicate that the influence of the replacement ratio for the front and side cracks of RAC is insignificant, with the former being straight and the latter relatively convoluted. At the age of three days, the damaged interface between aggregate and mortar is almost completely responsible for concrete failure; in addition to the damage of coarse aggregates, aggregate failure is also an important factor in concrete failure at other ages. The load–displacement curve of RAC at direct shearing can be divided into elasticity, elastoplasticity, plasticity, and stabilization stages. The brittleness of concrete decreases with its age, which is reflected in the gradual shortening of the elastoplastic stage. At 28 days of age, the peak direct shear force increases with the replacement ratio, while the trend is opposite at ages of 3 days, 7 days, and 14 days, respectively. The residual strength of RAC decreases inversely to the replacement ratio, with the rate of decline growing over time. A two-parameter RAC direct shear strength calculation formula was established based on the analysis of age and replacement rate to peak shear force of RAC. The relationship between cube compressive strength and direct shear strength of recycled concrete at various ages was investigated.

Image Processing Based on Three-Dimensional Stereo Vision

2014 ◽  
Vol 556-562 ◽  
pp. 5017-5020
Author(s):  
Ting Ting Wang
Keyword(s):  
Image Processing ◽  
Binocular Vision ◽  
Stereo Vision ◽  
Error Rate ◽  
Three Dimensional ◽  
Processing Method ◽  
Stereoscopic Vision ◽  
Average Error ◽  
Traditional Model ◽  
Average Error Rate

Three-dimensional stereo vision technology has the capability of overcoming drawbacks influencing by light, posture and occluder. A novel image processing method is proposed based on three-dimensional stereoscopic vision, which optimizes model on the basis of camera binocular vision and in improvement of adding constraints to traditional model, moreover ensures accuracy of later location and recognition. To verify validity of the proposed method, firstly marking experiments are conducted to achieve fruit location, with the result of average error rate of 0.65%; and then centroid feature experiments are achieved with error from 5.77mm to 68.15mm and reference error rate from 1.44% to 5.68%, average error rate of 3.76% while the distance changes from 300mm to 1200mm. All these data of experiments demonstrate that proposed method meets the requirements of three-dimensional imageprocessing.

A novel method to determine critical CTOA directly by load-displacement curve

2020 ◽  
Vol 230 ◽  
pp. 107013
Author(s):  
Ying Zhen ◽  
Xuyang Li ◽  
Yuguang Cao ◽  
Shihua Zhang
Keyword(s):  
Displacement Curve ◽  
Novel Method ◽  
Load Displacement

Research on the Relationship between Indenter Tip Radius and Hardness with a Self-Designed Nanohardness Test Device

2008 ◽  
Vol 392-394 ◽  
pp. 267-270
Author(s):  
Qiang Liu ◽  
Ying Xue Yao ◽  
L. Zhou
Keyword(s):  
Single Crystal ◽  
Indentation Depth ◽  
Single Crystal Silicon ◽  
Indentation Hardness ◽  
Displacement Curve ◽  
Test Device ◽  
Crystal Silicon ◽  
Load Displacement ◽  
Depth Sensitivity ◽  
Tip Radius

Nanoindentation device has the ability to make the load-displacement measurement with sub-nanometer indentation depth sensitivity, and the nanohardness of the material can be achieved by the load-displacement curve. Aiming at the influence law of indenter tip radius to indentation hardness, testing on the hardness of single-crystal silicon were carried out with the new self-designed nanohardness test device based on nanoindentation technique. Two kinds of Berkovich indenter with radius 40nm and 60nm separately were used in this experiment. According to the load-depth curve, the hardness of single-crystal silicon was achieved by Oliver-Pharr method. Experimental results are presented which show that indenter tip radius do influence the hardness, the hardness value increases and the indentation size effect (ISE) becomes obvious with the increasing of tip radius under same indentation depth.

Detection of Microbubbles Using the Hough Transform

2013 ◽  
Vol 378 ◽  
pp. 478-482
Author(s):  
Yoshihiro Mitani ◽  
Toshitaka Oki
Keyword(s):  
Image Processing ◽  
Error Rate ◽  
Hough Transform ◽  
Detection Method ◽  
Experimental Results ◽  
Average Error ◽  
Image Processing Techniques ◽  
Average Error Rate ◽  
Processing Techniques

The microbubble has been widely used and shown to be effective in various fields. Therefore, there is an importance of measuring accurately its size by image processing techniques. In this paper, we propose a detection method of microbubbles by the approach based on the Hough transform. Experimental results show only 4.49% of the average error rate of the undetected microbubbles and incorrectly detected ones. This low percentage of the error rate shows the effectiveness of the proposed method.

scholarly journals Spin Wave Based Approximate 4:2 Compressor

2021 ◽  
Author(s):  
Abdulqader Mahmoud ◽  
Frederic Vanderveken ◽  
Florin Ciubotaru ◽  
Christoph Adelmann ◽  
Said Hamdioui ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Error Rate ◽  
Energy Efficient ◽  
Directional Coupler ◽  
State Of The Art ◽  
The Other ◽  
Average Error ◽  
Majority Gate ◽  
Micromagnetic Simulations ◽  
Average Error Rate

In this paper, we propose an energy efficient SW based approximate 4:2 compressor comprising a 3-input and a 5-input Majority gate. We validate our proposal by means of micromagnetic simulations, and assess and compare its performance with one of the state-of-the-art SW, 45nm CMOS, and Spin-CMOS counterparts. The evaluation results indicate that the proposed compressor consumes 31.5\% less energy in comparison with its accurate SW design version. Furthermore, it has the same energy consumption and error rate as the approximate compressor with Directional Coupler (DC), but it exhibits 3x lower delay. In addition, it consumes 14% less energy, while having 17% lower average error rate than the approximate 45nm CMOS counterpart. When compared with the other emerging technologies, the proposed compressor outperforms approximate Spin-CMOS based compressor by 3 orders of magnitude in term of energy consumption while providing the same error rate. Finally, the proposed compressor requires the smallest chip real-estate measured in terms of devices.

scholarly journals Spin Wave Based Approximate Computing

2021 ◽  
Author(s):  
Abdulqader Mahmoud ◽  
Frederic Vanderveken ◽  
Florin Ciubotaru ◽  
Christoph Adelmann ◽  
Said Hamdioui ◽  
...  
Keyword(s):  
Real Estate ◽  
Error Rate ◽  
Energy Efficient ◽  
State Of The Art ◽  
Magnetic Tunnel Junction ◽  
Domain Wall Motion ◽  
Full Adder ◽  
Average Error ◽  
Approximate Computing ◽  
Average Error Rate

By their very nature Spin Waves (SWs) enable the realization of energy efficient circuits as they propagate and interfere within waveguides without consuming noticeable energy. However, SW computing can be even more energy efficient by taking advantage of the approximate computing paradigm as many applications are error-tolerant like multimedia and social media. In this paper we propose an ultra-low energy novel Approximate Full Adder (AFA) and a 2-bit inputs Multiplier (AMUL). The approximate FA consists of one Majority gate while the approximate MUL is built by means of 3 AND gates. We validate the correct functionality of our proposal by means of micromagnetic simulations and evaluate the approximate FA figure of merit against state-of-the-art accurate SW, 7nm CMOS, Spin Hall Effect (SHE), Domain Wall Motion (DWM), accurate and approximate 45nm CMOS, Magnetic Tunnel Junction (MTJ), and Spin-CMOS FA implementations. Our results indicate that AFA consumes 43% and 33% less energy than state-of-the-art accurate SW and 7nm CMOS FA, respectively, and saves 69% and 44% when compared with accurate and approximate 45nm CMOS, respectively, and provides a 2 orders of magnitude energy reduction when compared with accurate SHE, accurate and approximate DWM, MTJ, and Spin-CMOS, counterparts. In addition, it achieves the same error rate as approximate 45nm CMOS and Spin-CMOS FA whereas it exhibits 50% less error rate than the approximate DWM FA. Furthermore, it outperforms its contenders in terms of area by saving at least 29% chip real-estate. AMUL is evaluated and compared with state-of-the-art accurate SW and 16nm CMOS accurate and approximate state-of-the-art designs. The evaluation results indicate that it saves at least 2x and 5x energy in comparison with the state-of-the-art SW designs and 16nm CMOS accurate and approximate designs, respectively, and has an average error rate of 10%, while the approximate CMOS MUL has an average error rate of 12.5%, and requires at least 64% less chip real-estate.

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