• Steel and Composite Structures
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• v.36 no.5
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• pp.493-506
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• 2020

The load-slip relationship of the shear connection is an important parameter in design and analysis of composite structures. In this paper, a load-slip curve prediction method of the shear connection based on the artificial neural networks (ANNs) is proposed. The factors which are significantly related to the structural and deformation performance of the connection are selected, and the shear stiffness of shear connections and the transverse coordinate slip value of the load-slip curve are taken as the input parameters of the network. Load values corresponding to the slip values are used as the output parameter. A twolayer hidden layer network with 15 nodes and 10 nodes is designed. The test data of two different forms of shear connections, the stud shear connection and the perforated shear connection with flange heads, are collected from the previous literatures, and the data of six specimens are selected as the two prediction data sets, while the data of other specimens are used to train the neural networks. Two trained networks are used to predict the load-slip curves of their corresponding prediction data sets, and the ratio method is used to study the proximity between the prediction loads and the test loads. Results show that the load-slip curves predicted by the networks agree well with the test curves.

• Steel and Composite Structures
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• v.42 no.4
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• pp.477-487
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• 2022

The shear stiffness of headed-stud shear connectors has no unified definition due to the nonlinear characteristics of its load-slip relationship. A unified framework was firstly adopted to develop a general expression of shear load-slip equation for headed-stud shear connectors varying in a large parameter range based on both force and energy balance. The pre- and post-yield shear stiffness were then determined through bilinear idealization of proposed shear load-slip equation. An updated and carefully selected push-out test database of 157 stud shear connectors, conducting on studs 13~30mm in diameter and on concretes 30~180 MPa in cubic compressive strength, was used for model regression and sensitivity analysis of shear stiffness. An empirical calculation model was also established for the stud shear stiffness. Compared with the previous models through statistical analysis, the proposed model demonstrates a better performance to predict the shear load-slip response and stiffness of the stud shear connectors.

• Korea-Australia Rheology Journal
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• v.15 no.2
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• pp.55-61
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• 2003

The steady shear flow properties of vaseline generally used as a base of the pharmaceutical dosage forms were studied in the consideration of wall slip phenomenon. The purpose of this study was to show that how slip may affect the experimental steady-state flow curves of semisolid ointment bases and to discuss the ways to eliminate (or minimize) wall slip effect in a rotational rheometer. Using both a strain-controlled ARES rheometer and a stress-controlled AR1000 rheometer, the steady shear flow behavior was investigated with various experimental conditions ; the surface roughness, sample preparation, plate diameter, gap size, shearing time, and loading methods were varied. A stress-controlled rheometer was suitable for investigating the flow behavior of semisolid ointment bases which show severe wall slip effects. In the conditions of parallel plates attached with sand paper, treated sample, smaller diameter fixture, larger gap size, shorter shearing time, and normal force control loading method, the wall slip effects could be minimized. A critical shear stress for the onset of slip was extended to above 10,000 dyne/$\textrm{cm}^2$. The wall slip effects could not be perfectly eliminated by any experimental conditions. However, the slip was delayed to higher value of shear stress by selecting proper fixture properties and experimental conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.234-243
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• 2002

When a vehicle is operated over sort terrain, torque(or soil thrust) applied to driving wheel brings about shear displacement far soil due to compression and shear failure of soil under tire. This shear displacement give rise to slip and a additional sinkage due to slip. This additional sinkage is usually referred to as slip-sinkage. The slip-sinkage is affected by soil conditions and inflation pressure of tire. This slip-sinkage influence tractive performance on driving wheel . We conducted the experimental study far investigating the effect of slip on sinkage and tractive performance of driving wheel, such as motion resistance, thrust and drawbar pull. The experiment was carried out over three different soil conditions(soft, hard and very hard soil) far a tire with three levels of inflation pressure(120kPa, 240kPa and 360kPa). The results of this study show qualitatively slipsinkage characteristics and slip-tractive performance relationships of driving wheel with soil conditions and inflation pressure of tire.

• Structural Engineering and Mechanics
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• v.7 no.4
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• pp.413-432
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• 1999

A macro-element model is developed to account for shear deformation and bond slip of reinforcement bars in the beam-column joint region of reinforced concrete structures. The joint region is idealized by two springs in series, one representing shear deformation and the other representing bond slip. The softened truss model theory is adopted to establish the shear force-shear deformation relationship and to determine the shear capacity of the joint. A detailed model for the bond slip of the reinforcing bars at the beam-column interface is presented. The proposed macro-element model of the joint is validated using available experimental data on beam-column connections representing exterior joints in ductile and nonductile frames.

• Korea-Australia Rheology Journal
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• v.20 no.2
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• pp.51-58
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• 2008

This paper describes a two-step Tikhonov regularization procedure for converting the steady shear data generated by parallel-disk viscometers, in the presence of wall slip, into a shear stress-shear rate function and a wall shear stress-slip velocity functions. If the material under test has a yield stress or a critical wall shear stress below which no slip is observed the method will also provide an estimate of these stresses. Amplification of measurement noise is kept under control by the introduction of two separate regularization parameters and Generalized Cross Validation is used to guide the selection of these parameters. The performance of this procedure is demonstrated by applying it to the parallel disk data of an oil-in-water emulsion, of a foam and of a mayonnaise.

• Steel and Composite Structures
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• v.17 no.6
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• pp.967-980
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• 2014

In regions of high shear forces in composite bridges, headed stud shear connectors need to be arranged with a small spacing in order to satisfy the design requirement of resisting the high interface shear force present at this location. Despite this, studies related to groups of headed studs are somewhat rare. This paper presents an investigation of the static behaviour of grouped stud shear connectors in high-strength concrete. Descriptions are given of five push-out test specimens with different arrangements of the studs that were fabricated and tested, and the failure modes, load-slip response, ultimate load capacities and related slip values that were obtained are reported. It is found that the load-slip equation given by some researchers based on a single stud shear connector in normal strength concrete do not apply to grouped stud shear connectors in high-strength concrete, and an algebraic load-slip expression is proposed based on the test results. Comparisons between the test results and the formulae provided by some national codes show that the equations for the ultimate capacity provided in these codes are conservative when used for connectors in high-strength concrete. A reduction coefficient is proposed to take into account the effect of the studs being in a group.

• Steel and Composite Structures
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• v.45 no.3
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• pp.425-436
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• 2022

The mechanical behaviors of the prefabricated steel-concrete composite beams are usually affected by the strength and the number of shear studs. Furthermore, the discrete degree of the arrangement for shear stud clusters, being defined as the clustering degree of shear stud λ in this paper, is an important factor for the mechanical properties of composite beams, even if the shear connection degree is unchanged. This paper uses an experimental and calculation method to investigate the influence of λ on the mechanical behavior of the composite beam. Five specimens (with different λ but having the same shear connection degree) of prefabricated composite beams are designed to study the ultimate supporting capacity, deformation, slip and shearing stiffness of composite beams. Experimental results are compared with the conventional slip calculation method (based on the influence of λ) of prefabricated composite beams. The results showed that the stiffness in the elastoplastic stage is reduced when λ is greater than 0.333, while the supporting capacity of beams has little affected by the change in λ. The slip distribution along the beam length tends to be zig-zagged due to the clustering of studs, and the slip difference increases with the increase of λ.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.385-390
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• 2001

This paper presents a nonlinear analysis technique with slip, the effects of slip modulus and composite action by shear connector on behavior and capacity in composite structure of sandwich system. As a results of this study, it proved that the slip modulus, in case of shear behavior, seldom influence load-resistance capacity such as yield and ultimate load, but in case of flexural behavior, it appropriately influence load-resistance capacity because of stress redistribution by slip. In case of flexural behavior, analysis result for perfect-composite results in over-estimation and perfect-slip results in under-estimation on behavior and capacity. Therefore, it is desirable to model steel-concrete interface with partial-composite. The effects of slip on behavior and capacity are less in case of positive composite than loosely composite, and it proved that composite action by shear connector improve the load-resistance capacity of this system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.577-580
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• 2003

Stress state of chip formation zone is one of the main problems in metal cutting mechanics. In two-dimensional case this process is usually considered as consistent shears of work material along single of several shear surfaces. separating chip from workpiece. These shear planes are assumed to be trajectories of maximum shear stress forming corresponding slip-line field. This paper suggests new approach to the constriction of slip-line field, which Implies uniform compression in chip formation zone. On the base of given model it has been found that imaginary shear line in orthogonal cutting is close to the trajectory of maximum normal stress and the problem about its determination have been considered. It has been shown that there is a second central slip-line field inside chip, which corresponds well to experimental data about stress distribution on tool rake face and tool-chip contact length. The suggested model could be useful in solution of various problems of machining.