Shear Capacity Study on Double-Nut Stud Shear Connector

2012 ◽  
Vol 512-515 ◽  
pp. 1991-1994
Author(s):  
Yang Wang ◽  
Tian Li

A new stud—double-nut stud was present. The goals of the study were two fold, firstly to compare with traditional stud and secondly to search the affect factors of capacity, get calculation equations .We present an analysis of double-nut stud, include different concrete strength and different stud size. This study showed double-nut stud is better than traditional stud, for it has higher shearing stiffness and bearing capacity, makes steel beam and the concrete slab to work together. These results suggest that all equations of stud are not applicable computation double -nut stud, it should make 1.35-1.5 adjustment coefficient.

2011 ◽  
Vol 99-100 ◽  
pp. 166-169
Author(s):  
Yi Min Dai ◽  
Xu Guang Yan ◽  
Jing Chen ◽  
Xiang Jun Wang

Based on the test data of twelve push-out specimens with different holes filling different materials,the paper compared and analyzed the capacity and the corresponding slip value of the stud shear connector. The results show that, as to the two different kinds of holes shape ,the strength of the stud shear connectors of square push-out specimens was huger than that of circular specimens with the same condition; the strength of stud shear connectors in steel-concrete composite structure was decided by the strength of concrete surrounding the shear in the holes, with increasing concrete strength, the strength of stud shear connectors improved greatly; The outputs of this study are very useful for further understanding of the characteristics of the stud,it is also expected that the results presented in this paper should be valuable for the design of the composite beams.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2958 ◽  
Author(s):  
Jun Chen ◽  
Wei Wang ◽  
Fa-Xing Ding ◽  
Ping Xiang ◽  
Yu-Jie Yu ◽  
...  

The high-strength bolt shear connector in prefabricated concrete slab has advantages in applications as it reduces time during the construction of steel-concrete composite building structures and bridges. In this research, an innovative and advanced bolt shear connector in steel-concrete composite structures is proposed. To investigate the fundamental mechanical behavior and the damage form, 22 static push-off tests were conducted with consideration of different bolt dimensions, the reserved hole constraint condition, and the dimension of slab holes. A finite element (FE) model was established and verified by using test results, and then the model was utilized to investigate the influence of concrete strength, bolt dimension, yield strength, bolt pretension, as well as length-to-diameter ratio of high strength bolts on the performances of shear connectors. On the basis of FE simulation and test results, new design formulas for the calculation of shear resistance behavior were proposed, and comparisons were made with current standards, including AISC, EN 1994-1-1, GB 50017-2017, and relevant references, to check the calculation efficiency. It is confirmed that the proposed equation is in better agreement with the experimental results.


2010 ◽  
Vol 163-167 ◽  
pp. 11-15
Author(s):  
Wen Qi Hou ◽  
Mei Xin Ye ◽  
Ye Zhi Zhang

Abstract. In the presented paper, reverse push-out test method was put forward and applied in the ultimate bearing capacity experiments of studs with concrete slab in tension. Ultimate bearing capacity experiments were carried out on 22 reverse push-out specimens composed of C50 or C40 concrete, 14MnNbq steel girder and Φ22studs. Results showed that ultimate bearing capacity of studs, pu, in tensile concrete slab is controlled by concrete failur, concrete strength, studs arragement and reinforcement ratio are the main influence factors of pu. Compared with that in compressive concrete, pu of Φ22 studs in tensile concrete is reduced about 30% averagely. According to the test results, a fitted load-slip relationship curve and a regression formula of pu for studs in tensile concrete were put forward, calculated results were in good agreement with the test results.


Author(s):  
Valentino Vigneri ◽  
Christoph Odenbreit ◽  
Matthias Braun

For composite beams using novel steel sheeting, the current Eurocode 4 rules sometimes overestimate the load bearing capacity of the shear connector. This is due to the larger rib heights and the smaller rib widths in comparison with the old studies, which have been carried out to calibrate the current design equations. The RFCS Project “DISCCO” investigated this phenomena and the working group under mandate M515, CEN/TC250/SC4/SC4.T3 is enhancing this equation and working on a proposal to be taken over in the new version of Eurocode 4.The proposed new equation covers the failure behaviour of the shear connection more in detail. The test results show, that the failure consists in a combined concrete cone and stud in bending. Due to the geometry of novel steel sheeting, the load bearing capacity of the headed stud shear connector is no more limited by its shear capacity, but by its bending capacity.A 3D non-linear finite element model is developed and validated through the support of the DISCCO push-out tests. A good agreement between numerical and experimental results in terms of force-slip behaviour is achieved. Special attention of this work lies on the numerical evaluation of the number of plastic hinges ny: a stress-based procedure is presented and the results are compared to the equations presented for new Eurocode 4.The numerical simulations show that the upper plastic hinge moves up as the slip increases due to the progressive crushing of the concrete in the rib. From the parametric study, it turns out that ny is linearly proportional to the embedment depth. Compared to pre-punched hole decking, through-deck welding specimen activates less plastic hinges in the studs because of the higher stiffness provided at the base of the stud.


2014 ◽  
Vol 578-579 ◽  
pp. 1522-1530
Author(s):  
Ya Chuan Kuang ◽  
Jin Ren Feng ◽  
Zhi Wu Yu ◽  
Xiao Jie Liu

Stud shear connector corrosion is an important factor for the durability degradation of steel-concrete composite structures. Stud shear connector corrosion in the natural environment is a slow process, so the shear capacity of deteriorated stud shear connector was studied by accelerate d deterioration using a galvanstatic method in this paper. Then, bending tests were conducted to study the structural behavior of steel-concrete composite beam after stud shear connector corrosion. Experimental results show that with the increase of conduction time, the corrosion rate of stud increases, the shear capacity of stud as well as the flexural capacity of steel-concrete composite beam decreases and the relative bond-slip between steel beam and concrete increases when loading. By the regression analysis of experimental results, formula was proposed to predict the shear capacity of studs after corrosion and the flexural capacity of deteriorated steel-concrete composite beam.


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 341 ◽  
Author(s):  
Shuangjie Zheng ◽  
Yuqing Liu ◽  
Yangqing Liu ◽  
Chen Zhao

In steel and concrete composite bridges, it is difficult to perforate the reinforcing bars through the circular holes of conventional perfobond shear connectors with multi-ribs. To ease the installation of perforating rebars, an alternative notched perfobond shear connector was proposed by cutting out the edge of the circular hole. This paper presents the push-out test results of six specimens which were fabricated and loaded to failure. The main purpose was to compare the failure mode, shear capacity and slip behavior of perfobond shear connectors using circular holes and notched holes. Furthermore, 43 nonlinear finite element simulations were performed to further study the effects of several variables, including the hole diameter, the hole distance, the hole number, the cut width, the perfobond thickness, the concrete strength, the rebar diameter, the rebar strength, and the steel strength. The parametric results were generated to evaluate the shear capacity equations for perfobond shear connectors. Finally, an analytical model was developed to estimate the shear capacity of notched perfobond shear connectors.


Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 29 ◽  
Author(s):  
Shuangjie Zheng ◽  
Chen Zhao ◽  
Yangqing Liu

In composite structures, the perfobond connector is an alternative type of shear connector which consists of a steel plate with a certain number of holes. The load–slip relationship is critical for structural analysis and numerical simulation of composite structures using perfobond connectors. In this study, push-out tests were conducted on 72 specimens to obtain the load–slip behaviors of perfobond connectors. Based on the test results, parametric study was performed to analyze the effects of changing the hole geometry, the concrete strength, the configuration of the rebar in hole, the dimensions of the perfobond rib, and the size of the concrete slab. Furthermore, the characteristics and physical meanings of the load–slip curves were analyzed, and the limits and conditions for theoretical expressions were derived. Finally, an analytical model was proposed to express the load–slip relationship of perfobond connectors covering a wide range of design variables.


2019 ◽  
Vol 5 (10) ◽  
pp. 2081-2092
Author(s):  
Senqiang Lu ◽  
Wei Zhao ◽  
Puge Han ◽  
Zhenyuan Hang

In order to achieve a kind of shear connector suitable for rapid-assembling steel-concrete composite beams, a new type of hybrid shear connectors is proposed, in which the concrete slab with prefabricated circular holes and the steel beam with welded studs are installed and positioned, and then epoxy mortar is filled in the prefabricated hole to fix the studs. To study the mechanical behavior of these hybrid connectors, test on 18 push-out specimens with different prefabricated circular holes are carried out. ABAQUS finite element software is adopted to verify the relationship between the numerical simulation and experiment, influences of the epoxy mortar strength and prefabricated circular holes diameter are studied. The results show that filling epoxy mortar in the prefabricated hole is beneficial to improve the stiffness and bearing capacity of the specimen; the change of epoxy mortar strength has a certain impact on the bearing capacity and stiffness of the hybrid connector; In the case of the same strength of the filling material, the size of the prefabricated circular holes diameter directly affects the stiffness and bearing capacity of the shear stud. The shear capacity equations proposed by considering the epoxy mortar strength and prefabricated holes diameter, and it has a wide applicability.


Author(s):  
Bruna Catoia ◽  
Arthur Lima Rocha ◽  
Marcelo de Araújo Ferreira

ABSTRACT: Provided that the anchorage capacity is guaranteed at the supports, the bearing capacity of hollow core slabs depends on the shear capacity of the pretensioned concrete webs, wherein the critical section is in a region between h and 2h from the support. For line loads acting within 2h to 6h from the supports, especially for shallow slabs 150 to 200 mm deep, it is likely to have flexure-shear cracks within the transfer region, wherein the bearing capacity is highly affected by the actual prestressing forces at the critical section. Therefore, one of the major questions pondered by structural engineers is to determine the effective amount of prestressing force that affects the shear resistance mechanism near to the support. According to ABNT NBR 14861:2011, the shear capacity is based on the flexure-shear mechanism, wherein the shear strength is a sum of the tensile concrete strength in the slab webs plus the contribution of the prestressing forces at the critical section, wherein a coefficient of 0.15 is considered. However, in both codes NBR 14861 and NBR 6118 it is required that this coefficient 0.15 should be further multiplied by an additional reduction factor in order to take into account the effect of the transmission length near to the support. Considering the current revision of the NBR 14861, this paper presents a theoretical-experimental comparison from standard shear tests of hollow core slabs with nominal depths from 150 to 200 mm carried out in different research at NETPre-UFSCar. Based on the analytical study of each term of the equation for the flexure-shear capacity, it has been observed that the coefficient 0.15 provides a conservative limit for the contribution of the actual prestressing force. Therefore, there is no need to apply any additional reduction factor in order to guarantee a safe design limit for the shear capacity.


2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Shuangjie Zheng ◽  
Chen Zhao ◽  
Yangqing Liu

In steel and concrete composite structures, it is unfavourable to install many headed studs or perfobond ribs with narrow spacings at the joints. To solve this problem, a new type of a mixed shear connector was developed by combining a headed stud and perfobond rib at the same steel beam flange. In this paper, totally nine push-out tests were conducted. The main purpose was to compare the failure mode and the load-slip behavior of the headed stud, perfobond rib, and mixed shear connector. Furthermore, 19 nonlinear finite element simulations were performed. The effects of connector dimension and material properties on the structural behaviors of mixed shear connectors were studied. Based on the experimental and parametric study, an analytical equation was finally proposed to evaluate the shear capacity of perfobond rib with a headed stud mixed shear connector.


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