• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.247-254
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• 2014

In this study, shear test performed to investigate the shear behavior of flat plate that reinforced by embedded GFRP(glass fiber reinforced polymer) plate with openings. Shape of the GFRP shear reinforcement is a plate with several openings to ensure perfect integration with concrete. The test parameters include the distance between the column face and the first line of GFRP plate and number of GFRP plate vertical strip. The result of test showed that when number of GFRP plate vertical strip was increased, shear strength improved. The shear strength for flat plate reinforced GFRP plate in various codes including ACI 318, BS 8110, EUROCODE 2, and KCI were compared to provide more rational approach for reinforced concrete flat plates with GFRP plate.

• Corrosion Science and Technology
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• v.23 no.2
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• pp.145-153
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• 2024

In the automotive industry, the hole expanding test is widely used to assess the formability of punched holes in sheets. This test provides a good representation of formability within the framework defined by the ISO 16630 standard. During hole expanding tests on galvanized high strength steels, a negative effect was observed when there was a delay between hole punching and expansion, as compared to performing both operations directly. This effect is believed to be caused by hydrogen aging, which occurs when hydrogen diffuses towards highly-work hardened edges. Therefore, the aim of this study is to demonstrate the migration of hydrogen towards work-hardened edges in high strength Zn-coated steel sheets using a novel Thermal Desorption Analyzer (TDA) designed for small samples. This newly-developed TDA setup allows for the quantification of local diffusible hydrogen near cut edges. With its induction heating and ability to analyze Zn-coated samples while reducing artifacts, this setup offers flexible heat cycles. Through this method, a hydrogen gradient is observed over short distances in shear-cut galvanized steel sheets after a certain period of time following punching.

• Journal of the Korea Concrete Institute
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• v.19 no.3
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• pp.301-312
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• 2007

A slab-column connection is susceptible to brittle punching shear failure, which may result in the necessity of shear reinforcement. In the present study, to investigate the earthquake resistance of newly developed lattice shear reinforcement, experimental study was performed for interior slab-column connections subjected to cyclic loading. For comparison, specimens with existing shear reinforcement method such as stud rail, shear band and stirrup were also tested. The test result showed that the structural capacity of the lattice shear reinforcement was superior to those of the existing methods and was greater than the code-specified strength. On the other hand, the existing methods did not significantly improve the shear strength of the specimens. The shear strengths of the existing methods were much less than the code-specified shear strength.

• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.38-45
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• 2018

Bridges are structures where safety must be ensured. Generally, the destruction mechanism of bridge deck shows punching shear. Lately, the high-strength concrete is often used to increase the lifespan of bridges. The benefits of using the high-strength concrete are that it increases the durability and strength. On the contrary, it reduces the cross-section of the bridges. This study suggested the optimal thickness of bridge deck with application of high-strength concrete and the study evaluated its structural performance experimentally. The evaluation result shows that 180 mm and 190 mm of thickness are optimal for 100 MPa and 120 MPa high-strength concrete bridge deck respectively.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.891-896
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• 2002

Flat plate is susceptible to punching shear failure at the slab-column connection, which may cause catastrophic structural collapse. To prevent such brittle failure, strength and ductility of the connection should be ensured. However, since it is very difficult to experimentally simulate the actual load and boundary conditions of the flat plate system, it is not easy to obtain reliable information and data regarding to the strength and ductility of the flat plate-column connection. In the present study, numerical studies were performed for interior connections of continuous flat plate. The results were compared with the existing experiments, and the variations of bending moment, shear, torsional moment around the connection were investigated. Based on the findings of the numerical studies, the disadvantages of current design methods were discussed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.2
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• pp.121-128
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• 2014

In this study, The purpose of this study is to experimentally investigate the shear behavior of reinforced flat plate embedded with GFRP(glass fiber reinforced polymer) plate with openings. The GFRP shear reinforcement is manufactured into a plate shape with several openings to ensure perfect integration with concrete. The test was performed on 7 specimens. the parameters include the type of reinforcement and amount of the shear reinforcement., From the test, we analysed the crack, failure mode, Strain, load-displacement graph. a calculation of the shear strength of reinforced flat plate with GFRP plate based on the ACI 318-11 was compared with the test results. The results of the experiment indicate that GFRP plate is successfully applied as a shear reinforcement in the flat plate under punching shear.

• International Journal of Railway
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• v.2 no.4
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• pp.131-138
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• 2009

Static tensile and fatigue tests were conducted using tensile-shear specimens to evaluate the fatigue strength of a SPCC sheet clinch joint. The maximum tensile strength of the specimen produced at the optimal punching force was 1750 kN. The fatigue endurance limit (=760 N) approached 43% of the maximum tensile load (=1750 N) at a load ratio of 0.1, suggesting that the fatigue limit is approximately half of the value of the maximum tensile strength. The FEM analysis showed that at the fatigue endurance limit, the maximum von-Mises stress of 373 MPa is very close to the ultimate tensile strength of the SPCC sheet (=382 MPa).

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.233-238
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• 2002

This study presents failure mechanisms for the pull-out strength of headed reinforcement for upper bound solution based on the limit theorem. The failure mechanisms to be presented follow the failure surface pattern of punching shear failure found in the joints of slab with a column. Several failure surfaces of the mechanisms have different characteristics for dissipation works and these mechanisms are able to interpret the role of bar details surrounding headed reinforcement.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.10-21
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• 2014

The joint of prefabricated steel grid composite deck is composed of concrete shear key and high-tension bolts. The flexural and shear strength of the joint were experimentally evaluated only by the bending and push-out test of the joint element. In this study the lateral load transfer behavior of the joint in deck structure system is experimentally evaluated. Several decks connected by the joint are prefabricated and loaded centrically and eccentrically. In the case of centrically loaded specimens, the analysis results show that for the same loading step the rotation angle of the joint with 4 high-tension bolts is larger than the case of the joint with 9 high-tension bolts. Consequently, flexural stiffness of deck and lateral load transfer decrease in the case of specimen with 4 high-tension bolts. But, in the case of eccentrically loaded specimens, it is found that there are no significant differences in the load transfer behavior. The further analysis results about the structural behavior of the joint show that lateral load transfer can be restricted by the load bearing capacity of the joint as well as punching shear strength of the slab. Furthermore, considering that high-tension bolts in the joint didn't reach to the yielding condition until the punching shear failure, increase in the number of high-tension bolts from 4 to 9 has a greater effect on the flexural stiffness of the joint and deck system than the strength of them.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.415-420
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• 2003

This Study is performed to analyze the behavior of inverted T-shaped Composite Basement Wall(CBW). For this, it is purposed to analyze the failure mechanisms of inverted T-shaped composite basement wall and propose the method of evaluating strength for design. The failure mechanisms would be devided into 4 type mechanisms from previous experimental results, that is hanger failure, punching shear failure, flexural failure and the buckling of H-pile. A strength evaluation procedure for CBW is induced by analyzing respective failure mechanism. Then, the strength for actual structure consisted of inverted T-shaped composite basement wall was evaluated and the expected failure mechanism was determined.