Behaviour of headed studs in composite beams: full-size tests

1989 ◽  
Vol 16 (5) ◽  
pp. 712-724 ◽  
Author(s):  
B. S. Jayas ◽  
M. U. Hosain
Keyword(s):  
Empirical Equation ◽  
Composite Beams ◽  
Shear Capacity ◽  
Horizontal Shear ◽  
Principal Mode ◽  
Full Size ◽  
Pull Out ◽  
Shear Loads ◽  
Predicted Values ◽  
Good Agreement

This paper summarizes the results of tests conducted on four full-size composite beams and two full-size push-off specimens which are companions of the first two beams. In these specimens, the ribbed metal deck was placed perpendicular to the beam span. Concrete pull-out was the principal mode of failure. The ultimate horizontal shear loads observed in the push-off specimens agreed reasonably well with those predicted using an empirical equation proposed by the authors. The predicted values of flexural capacity, calculated indirectly using the same equation, were in good agreement with those observed in the four beam specimens. Key words: composite beam, headed shear stud, stud shear capacity, stud pull-out failure, full-size tests, perpendicular ribbed metal deck.

Behaviour of headed studs in composite beams: push-out tests

1988 ◽  
Vol 15 (2) ◽  
pp. 240-253 ◽  
Author(s):  
B. S. Jayas ◽  
M. U. Hosain
Keyword(s):  
Composite Beams ◽  
Shear Capacity ◽  
Concrete Slabs ◽  
Steel Beam ◽  
Principal Mode ◽  
Pull Out ◽  
Factor Design ◽  
Headed Stud ◽  
Load And Resistance Factor ◽  
Push Out

This paper briefly summarizes the results of tests conducted on 18 full-size push-out specimens and 4 pull-out specimens. The objective of the project was to study the behaviour of headed studs in composite beams with ribbed metal decks perpendicular and parallel to the steel beam. The longitudinal spacing of the headed studs and the rib geometry of the metal decks were the principal experimental parameters.Five of the push-out specimens had solid concrete slabs, in five specimens the ribbed metal deck was placed parallel to the steel beam, and in the remaining eight specimens the metal deck was perpendicular to the steel beam. In most cases 38 mm deck and 16 × 76 studs were used.Test results obtained by the authors appear to indicate that with some exceptions the current Canadian Standards Association and Load and Resistance Factor Design codes are able to predict stud strength correctly for specimens with solid slabs and with parallel ribbed slabs only when failure occurs owing to stud shearing, i.e., when the studs are spaced sufficiently apart. It is recommended that these codes include a provision to check the possibility of concrete-related failures when the longitudinal stud spacing approaches or falls below six times the stud diameter for solid and parallel ribbed slabs.Stud pull-out was the principal mode of failure in the specimens with perpendicular ribbed metal decks. An equation recently proposed by Hawkins and Mitchell appears to underestimate the capacity for specimens with 38 mm deck. For specimens with 76 mm deck, their equation overestimates the stud capacity. The authors have proposed two separate but similar empirical equations for specimens with 38 and 76 mm deck. Key words: composite beam, headed stud, stud shear capacity, stud pull-out failure, minimum stud spacing, perpendicular deck, parallel deck.

scholarly journals Finite element modelling of monotonic pull-out test of deformed steel rebar embedded in well-confined concrete

2021 ◽  
Vol 331 ◽  
pp. 05012
Author(s):  
Patria Kusumaningrum ◽  
Gigih Muslim Prayogo ◽  
Sri Tudjono
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Empirical Equation ◽  
Bond Stress ◽  
Confined Concrete ◽  
Bond Slip ◽  
Steel Rebar ◽  
Bond Model ◽  
Pull Out ◽  
Good Agreement

A finite element study carried out using LS DYNA and aimed to simulate the monotonic pull-out test of deformed steel rebar embedded in concrete is presented in this paper. Three models of the interface between deformed steel rebar and well-confined concrete, i.e. perfect bond model and two bond-slip models are observed and compared. Bond stress-slip response and rebar stress-slip response obtained numerically are validated with experimental data and empirical equations available from the literature. The full bond model overestimates the response, providing higher rebar stress. In the bond-slip models, good agreement is observed between numerical and experimental bond stress and rebar Stress–slip responses. The empirical equation of bond-slip proposed by Murcia-Delso and Shing (2014) is found to overestimate the peak bond stress.

scholarly journals Shear Performance Assessment of Sand-Coated GFRP Perforated Connectors Embedded in Concrete

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1906 ◽  
Author(s):  
Zhihua Xiong ◽  
Yuqing Liu ◽  
Yize Zuo ◽  
Haohui Xin
Keyword(s):  
Shear Strength ◽  
Parametric Analysis ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Pull Out ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Shear Performance ◽  
Embedment Length ◽  
Good Agreement

In order to evaluate the shear performance of sand-coated glass fiber-reinforced polymer (GFRP) perforated connectors (SCGPC) embedded in concrete, 8 pull-out tests were conducted. Finite element (FE) analysis considering GFRP failure and cohesion between GFRP and concrete of SCGPC were conducted for parametric analysis. Effects of surface treatment, hole’s radius, embedment length, and multi holes were examined. The test and theoretical analysis revealed that the strength of SCGPC is considerably larger than GFRP Perforated Connector (GPC). The stiffness of SCGPC is determined by the adhesion between concrete and GFRP. When GFRP plate’s thickness is less than the critical thickness, the embedment length plays a major role in the strength of SCGPC. When embedment length is less than the effective bond length, the shear strength of SCGPC is governed by both the adhesion and GPC’s shear capacity; otherwise, the strength of SCGPC is governed by the adhesion strength. Furthermore, an empirical equation was suggested to predict the shear strength of SCGPC. The equation involves the failure mechanism of both bond and GPC and deals the strength of SCGPC into two ranges according to the embedment length. Good agreement was achieved between the strength prediction by the suggested equation and the parametric analysis result.

scholarly journals Seasonal Estimates and Uncertainties of Snow Accumulation from CloudSat Precipitation Retrievals

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 363
Author(s):  
George Duffy ◽  
Fraser King ◽  
Ralf Bennartz ◽  
Christopher G. Fletcher
Keyword(s):  
Time Scales ◽  
Snow Water Equivalent ◽  
Spatial Scales ◽  
Snow Accumulation ◽  
High Latitudes ◽  
Percentage Points ◽  
Snow Water ◽  
Time Periods ◽  
Predicted Values ◽  
Good Agreement

CloudSat is often the only measurement of snowfall rate available at high latitudes, making it a valuable tool for understanding snow climatology. The capability of CloudSat to provide information on seasonal and subseasonal time scales, however, has yet to be explored. In this study, we use subsampled reanalysis estimates to predict the uncertainties of CloudSat snow water equivalent (SWE) accumulation measurements at various space and time resolutions. An idealized/simulated subsampling model predicts that CloudSat may provide seasonal SWE estimates with median percent errors below 50% at spatial scales as small as 2° × 2°. By converting these predictions to percent differences, we can evaluate CloudSat snowfall accumulations against a blend of gridded SWE measurements during frozen time periods. Our predictions are in good agreement with results. The 25th, 50th, and 75th percentiles of the percent differences between the two measurements all match predicted values within eight percentage points. We interpret these results to suggest that CloudSat snowfall estimates are in sufficient agreement with other, thoroughly vetted, gridded SWE products. This implies that CloudSat may provide useful estimates of snow accumulation over remote regions within seasonal time scales.

scholarly journals Longitudinal shear capacity of the slabs of composite beams

1976 ◽  
Vol 3 (4) ◽  
pp. 514-522 ◽  
Author(s):  
M. N. El-Ghazzi ◽  
H. Robinson ◽  
I. A. S. Elkholy
Keyword(s):  
Composite Beam ◽  
Shear Failure ◽  
Concrete Slab ◽  
Compressive Force ◽  
Longitudinal Shear ◽  
Composite Beams ◽  
Shear Capacity ◽  
Slab Width ◽  
Two Parameters ◽  
Concrete Elements

The longitudinal shear failure of the slab of composite beams is constrained to occur at a predetermined shear surface. A method for calculating the longitudinal shear capacity of the slab of simply-supported steel–concrete composite beams is presented. The method is based on analyzing the stresses at failure of the concrete elements located at the slab shear surface.A design chart based on estimating the transverse normal stress required within the concrete slab to achieve the full ultimate flexural capacity of the composite beam is proposed. Alternatively, using elastic–plastic stress distribution across the concrete slab, the longitudinal compressive force due to bending and hence the applied moment can be predicted for any longitudinal shear capacity of the slab. The proposed design and analysis when compared to previous tests and analysis showed good agreement.The slab width and the shear span of the composite beam are found to be two important parameters which cannot be neglected when estimating the longitudinal shear capacity of the slab. These two parameters have been neglected in the empirical solutions previously adopted.

The Fatigue Behavior of Negative Moment Regions of Continuous Composite Beams at Low Temperatures

1975 ◽  
Vol 2 (1) ◽  
pp. 98-115
Author(s):  
A. E. Long ◽  
K. Van Dalen ◽  
P. Csagoly
Keyword(s):  
Fatigue Behavior ◽  
Bending Moment ◽  
Composite Beams ◽  
Horizontal Shear ◽  
Shear Connectors ◽  
Significant Difference ◽  
Show Evidence ◽  
Negative Moment ◽  
Central Support ◽  
Push Out

The fatigue behavior of the negative moment region of continuous steel–concrete composite beams under Canadian temperature conditions was studied. Tests were conducted on three 26 ft 0 in. (7.92 m) long beams, continuous over a central support, and on 11 conventional push-out specimens. These were supplemented by a theoretical study of the internal forces in the beams using an iterative method of analysis.The close agreement between measured and theoretical strains and deflections indicated that good interaction was achieved throughout the length of the beams. The beams sustained 500 000 cycles of loading with no serious deterioration of composite action. The pattern of stud failures was consistent from beam to beam and reflected closely the calculated distribution of horizontal shear force at the steel–concrete interface. Stud shear connectors in the negative moment region where the slab had cracked in tension were found to be slightly less effective than studs in the positive bending moment regions.Neither the detailed study of individual connectors in the beams nor the results of the push-out tests show evidence of a reduction in the fatigue life of studs at −20 °F (−29 °C) relative to room temperature. The beams also exhibited no significant difference in their overall performance at these two temperatures.

Prediction of Thermal Conductivities of Fibre Reinforced Composites using a Thermal-Electrical Analogy

2005 ◽  
Vol 13 (6) ◽  
pp. 637-644
Author(s):  
Young Jun Cho ◽  
Jae Ryoun Youn ◽  
Tae Jin Kang ◽  
Sung Min Kim
Keyword(s):  
Fibre Orientation ◽  
Reinforced Composites ◽  
Laminate Composites ◽  
Reinforced Composite ◽  
Electrical Analogy ◽  
Out Of Plane ◽  
Predicted Values ◽  
Fibre Reinforced Composites ◽  
Good Agreement ◽  
Thermal Conductivities

An approach for predicting the effective thermal conductivities of fibre reinforced composites has been developed, based on a thermal-electrical analogy. In the voxelization method, the unit cell of the laminate composites is divided into a number of volume elements, and the material properties considering the local variations of fibre orientation have been given to each element. By constructing a series-parallel thermal resistance network, the thermal conductivities of a fibre reinforced composite in both in-plane and out-of-plane directions have been predicted. The reported thermal conductivities of a graphite/epoxy composite of a balanced plain weave laminate were used for the comparison with the predicted values of the model, and good agreement was found.

Quantifying the thickness of each color material in multilayer transparent specimen based on transmission image

2020 ◽  
Vol 90 (21-22) ◽  
pp. 2522-2532
Author(s):  
Lijun Chen ◽  
Hua Shen ◽  
Fumei Wang
Keyword(s):  
Optical Depth ◽  
Low Cost ◽  
Estimating Equation ◽  
Color Film ◽  
Transparent Films ◽  
Transmission Image ◽  
Multilayer Specimen ◽  
Predicted Values ◽  
Physical Thickness ◽  
Good Agreement

Combing the color transmission image and the Beer–Lambert law shows a great application prospect in quantifying each material in multilayer specimen. Here, a novel, low-cost, and efficient optical algorithm is proposed to predict the thickness of each color material in a multilayer specimen from the color transmission image based on the Beer–Lambert Law. In this work, a normal scanner is employed to achieve the color transmission image of the monochrome transparent films. RGB values represent the transmitted intensity. A linear relationship between the optical depth and physical thickness is observed under different monochromatic lights. It is supposed that for a multilayer transparent film which consisted of different monochrome transparent films, the optical depth is related to the physical thickness of each monochrome transparent component. Therefore, an estimating equation is proposed to predict the thickness of each color material in the multilayer specimen. According to the result, the standard deviation of predicted thickness and practical thickness of each color film in the multilayer specimen is 0.93%. Fairly good agreement and high accuracy are obtained between the practical and predicted values, and the validity of this method is confirmed.

scholarly journals Foam Formation by Compression/Decompression Cycle of Soft Porous Media

2020 ◽  
Vol 4 (3) ◽  
pp. 31
Author(s):  
Phillip Johnson ◽  
Mauro Vaccaro ◽  
Victor Starov ◽  
Anna Trybala
Keyword(s):  
Mechanical Properties ◽  
Porous Media ◽  
Porous Material ◽  
Foam Formation ◽  
Compression Device ◽  
The Media ◽  
Minimum Separation ◽  
Soft Porous Media ◽  
Predicted Values ◽  
Good Agreement

A theory of the amount of foam produced by compression/decompression cycles of a soft porous media is developed. The amount of foam produced was found to be dependent on both the amount of surfactant within the media and the minimum separation between the plates of the compression device. The latter is determined by the mechanical properties of the soft media. The theory also shows the importance of the decompression of the media as this is the mechanism of where the air penetrates into the soft porous material. The accumulated air is used during the compression stage for foam formation. The theoretically predicted values of foam mass are found to have good agreement with experimental observations, which validates the theory predictions. The theory also predicts independence of the foam produced in terms of the frequency of compression/decompression cycles, which agrees with our experimental observations.

Theoretical Model of the Spanwise Mixing Caused by Periodic Incoming Wakes

1994 ◽  
Author(s):  
K. Imanari
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Turbulent Diffusion ◽  
Axial Flow ◽  
Single Stage ◽  
Mixing Coefficients ◽  
Predicted Values ◽  
Good Agreement ◽  
Axial Flow Compressors

A theoretical model is proposed for the spanwise mixing caused by periodic incoming wakes in the context of turbulent diffusion in axial-flow compressors prior to repeating-stage conditions. The model was used to predict the spanwise mixing coefficients across a stator of a single-stage compressor without IGVs. The correctness of the theory was demonstrated by the results that the predicted values were in good agreement with the associated experimental data.

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