Behavior and design method for offset multi-wedges swaged couplers under uniaxial tension

2020 ◽  
pp. 136943322096847
Author(s):  
Zexin Liu ◽  
Peijun Wang ◽  
Yuanjian Liu ◽  
Ying Chen ◽  
Fangzhou Liu

This paper proposed an Offset Multi-Wedges Swaged Couplers (OMWSC) as mechanical connection of steel rebars. The behavior of the connection consisting of two steel rebars connected by one OMWSC under uniaxial tension is investigated by Finite Element Model (FEM) simulations, which is verified through test results by considering the load-displacement curve, the failure mode and the failure deformation, and the insertion force to install the wedges. Parameter studies are carried out using the verified FEM. Studied parameters included the rebar surface type, the wedge diameter, the steel rebar diameter, the overlap ratio of the wedges that is defined as the ratio of wedge distance to the effective wedge distance, the extrusion ratio that is defined as a half of the wedge diameter to the gap of the two rebars, and the edge distance. Design equations for the coupler and the wedge of an OMWSC are proposed. Verification of the proposed design methods proved the OMWSC designed using the proposed method would not fail prior to the failure of steel bars.

2000 ◽  
Author(s):  
Won-Bae Na ◽  
Tribikram Kundu ◽  
Mohammad R. Ehsani

Abstract The feasibility of detecting interface degradation and separation of steel rebars in concrete beams using Lamb waves is investigated in this paper. It is shown that Lamb waves can easily detect these defects. A special coupler between the steel rebar and ultrasonic transducers has been used to launch non-axisymmetric guided waves in the steel rebar. This investigation shows that the Lamb wave inspection technique is an efficient and effective tool for health monitoring of reinforced concrete structures because the Lamb wave can propagate a long distance along the reinforcing steel bars embedded in concrete as the guided wave and is sensitive to the interface debonding between the steel rebar and concrete.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hanquan Yuan ◽  
Lihua Zhu ◽  
Haoyi Zhou ◽  
Dong Jiang ◽  
Baoquan Liu ◽  
...  

The coal crusher generates large vibrations when crushing coal blocks, which can affect the equipment itself, as well as the safety of the structure. In order to study the dynamic characteristics of coal crusher, a finite element model of the coal crusher chamber in the Shangluo power plant was built by using ABAQUS. Firstly, modal and harmonic response analyses were conducted, and the comparison shows that the numerical results are basically in accordance with the test results. Then, shock absorption research was performed using a parametric analysis that included the stiffness and position of the spring vibration isolator, the mass, and material of the vibration-isolation platform. Finally, the dynamic coefficient of a coal crusher was discussed. The results showed that, compared with the stiffness of the spring vibration isolator, the mass of the vibration-isolation platform had more influence on the vibration displacement of the coal crusher. To achieve better vibration isolation, the concrete platform is suggested, and the eccentricity of the spring vibration isolator should not exceed 5%. When static design method is adopted to calculate the bearing capacity of the supporting structure subjected to the dynamic load of the coal crusher, the dynamic coefficient of a coal crusher is suggested as 1.5.


Author(s):  
Jennifer M. Bastiaan ◽  
Amir Khajepour

A physical testing program is performed in support of finite element model creation for a 50-series passenger car tire. ABAQUS finite element analysis software is used along with its standard material models. Uniaxial tension testing of tire samples cut from the tread composite, tread rubber and sidewall composite is performed in order to obtain material properties. Hyper-elastic material coefficients for tread rubber are fit using uniaxial tension test data. Results show that the Arruda-Boyce hyper-elastic material model fits the test data well and it predicts reasonable overall behavior in uniaxial tension and uniaxial compression. Most other hyperelastic material models are found to predict unrealistic behavior in uniaxial compression for the tire samples, especially in the 0 to 20% compressive strain range. Frequency response testing of two inflated passenger car tires of different sizes, makes and models is also performed to assist in defining the viscoelastic material model for tread rubber. Test results show that tire modal damping is in the 2 to 4% range for most modes below 200 Hz, and the response curves, modal density and modal damping are remarkably similar for the two tires tested. The tire finite element model with updated material properties is simulated for nine combinations of air inflation pressure and vertical load in order to calculate static loaded radius. The analysis results are compared with physical test results and the analysis results are found to deviate at most by 3% compared to the tests.


2018 ◽  
Vol 7 (4.37) ◽  
pp. 127
Author(s):  
Aamer Najim Abbas ◽  
Nura Jasim Muhammed

Eight (120 mm) square and (1 m) long reinforced concrete columns were tested under axial load to large inelastic deformations. The main purpose of this research was to investigate the behavior of column sections confined by rectilinear ties. Major variables considered in this program included: (1) Distribution of longitudinal and lateral steel, including unbalanced section due to the asymmetric distribution of reinforcing steel bars (2) type of concrete; normal concrete and self-compacting concrete. Finite element model was performed to validate the experimental results of this investigation. Test results indicate that a asymmetric distribution longitudinal bars results in desired performance of columns. Unsupported longitudinal bars and its number effective only at large deformations and result in rapid deterioration of column behavior at a later stage. There is 8.75% and 35.65% decrease in ultimate capacity under the control column, asymmetric distribution of reinforcing steel bars appears a more brittle while symmetric bars yields more elastic than brittle, it adds safety when failure happens.   


2020 ◽  
Vol 10 (14) ◽  
pp. 4935
Author(s):  
Peiyao Zhang ◽  
Quanquan Guo ◽  
Fei Ke ◽  
Weiyi Zhao ◽  
Yinghua Ye

Double steel-concrete composite shear wall is a novel composite structure. Due to its good mechanical properties, it has been considered as a substitute for reinforced concrete walls in nuclear facilities, marine environmental structures, and high-rise buildings. However, the design method of the double-steel concrete composite shear wall is lacking. The purpose of this paper is to propose the bending capacity formula under large and small eccentric loads. By summarizing the test results of 49 steel-concrete composite double shear walls under cyclic loading from different studies, it was found that the bending failure of double-steel-concrete composite shear walls was featured by the concrete crushing at the bottom. A finite element model was established and it could simulate the axial and bending performance of double steel-concrete composite shear walls reasonably well. According to the experimental results and FE analysis, the primary assumptions for calculating the axial and bending bearing capacity of the double steel-concrete composite shear walls were proposed. Based on these assumptions, the bearing capacity formulas were derived according to the equilibrium theory of the cross section. The calculation results obtained by the bearing capacity formulas were in good agreement with the test results.


2016 ◽  
Vol 10 (1) ◽  
pp. 625-640
Author(s):  
Xingyou Yao ◽  
Yanli Guo

The aim of this paper is to investigate the inelastic bending capacity and design method of cold-formed steel lipped channel bending members. The bending tests were conducted on 30 cold-formed steel lipped channel members. The nominal yield stress and the nominal thickness of the bending members were 235 MPa and 2mm. The theoretical global buckling stress was higher three times than the yield stress which can make sure the failure of members were in inelastic stage. For each specimen, an analytical analysis using Finite Element Method (FEM) was also conducted considering the influence of the boundary, the ultimate bending capacity, and the failure mode could also be captured. The test results show that the Chinese cold-formed steel specification Technical code of cold-formed thin-walled steel structures (GB50018-2002) is conservative for lipped channel bending sections in inelastic stage. The test results are used to put forward to a revised design method based on effective width method for the current Chinese cold-formed steel specification. The comparison on the bending capacity between the test results and the calculated results by using the proposed method, effective width method and direct strength method in North American cold-formed steel specification (AISI-S120-2016(draft)) shows that the proposed method can consider the inelastic reserve capacity of bending members well. The failure modes and bending capacity of bending members obtained using the idealized shell finite element model, which are close to the experimental results, shows that the idealized model is very well to model the buckling behavior and calculate capacity of bending members.


2020 ◽  
Vol 4 (4) ◽  
pp. 182
Author(s):  
Luciano Ombres ◽  
Salvatore Verre

In the paper, the bond between a composite strengthening system consisting of steel textiles embedded into an inorganic matrix (steel reinforced grout, SRG) and the concrete substrate, is investigated. An experimental investigation was carried out on medium density SRG specimens; direct shear tests were conducted on 20 specimens to analyze the effect of the bond length, and the age of the composite strip on the SRG-to-concrete bond behavior. In particular, the tests were conducted considering five bond length (100, 200, 250, 330, and 450 mm), and the composite strip’s age 14th, 21st, and 28th day after the bonding. Test results in the form of peak load, failure modes and, bond-slip diagrams were presented and discussed. A finite element model developed through commercial software to replicate the behavior of SRG strips, is also proposed. The effectiveness of the proposed numerical model was validated by the comparison between its predictions and experimental results.


2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.


2011 ◽  
Vol 243-249 ◽  
pp. 1528-1535
Author(s):  
Yu Zhao ◽  
Yong Jun Zhou ◽  
Jing Sun ◽  
Jin Tao Tang ◽  
Xu Li

Cable-stayed self-anchored suspension composed bridges have novel structures and aesthetic appearance with complex system and difficulty for design and construction. In order to acquire a better knowledge of the load-carrying capability of this type of bridges, based on a real bridge and the theory of abnormal similarity, a full-bridge scaled down(1:20) test model was built to simulate the whole process of construction. The test results were preferably fit the theoretical calculation value. It can be seen that the design of the bridge was reasonable, and the accuracy of the calculation of finite element model was verified at the same time. The test and the related results can be used as the reference for the test and design of the similar bridges.


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