• Journal of the Korean Society for Railway
• /
• v.6 no.3
• /
• pp.179-185
• /
• 2003

This paper was to find out the design methodology for korean railway station of steel structure using by wooden structure system. Traditionally Korean architecture was made by wooden structure system what is called Gong-Po (wooden bracket structure system). The abundant ornament of Korean architecture is resulted from the composition rule of Gong-Po(wooden bracket structure system). But Korean wooden structural system have a limit in constructing large building, for example railway station, airport terminal, convention center etc. It is needed to convert wooden structure system into steel structure system. But there are many differences between wooden structure and steel structure in texture, material strength, joint system of elements etc. In this paper, we will show you how to make a joint system for steel structure of railway station and how to present the traditionality of Korean architecture in railway station.

• Journal of Welding and Joining
• /
• v.7 no.3
• /
• pp.36-43
• /
• 1989

The furnace brazing in a Ar of copper to martensitic stainless steel(13.5Cr) using Cu-(5~8%)P-(0~8%)Sn powders was investigated. Shear strength, wettability, reacted layer, defect ratio at the stainless steel interface was evaluated. As Sn was added to the Cu-P powders, defect ratio and P content at the stainless steel interface decreased. And also as Sn was added, defect form at the stainless steel interface changed from the continuous layer to the discrete type, and shear strength of the brazed joint increased.

• Journal of the Korean Society of Industry Convergence
• /
• v.22 no.6
• /
• pp.615-626
• /
• 2019

In this study, the applicability of PHC pile jointing method using rectangular steel tubular was studied. PHC pile joints are welded and bolt assembly. The bolt assembly method is a method that improves the various problems of welded joints. Numerical analysis and tests were conducted to analyze the applicability of the PHC pile jointing method using a rectangular steel tubular. The tests were carried out to test the material properties of the rectangular steel tubular material and the bending test of the pile joints. The numerical analysis was interpreted in the same conditons as the tests conditions. As a result, the material strength of each rectangular steel tubular could be used as a joint material. In the bending test, it was evaluated as a sTable material above the allowable stress of piles. In the numerical analysis results under the same conditions as the tests, it was possible to apply the pile joint material without exceeding the allowable stress of the material.

• Journal of Welding and Joining
• /
• v.20 no.4
• /
• pp.510-516
• /
• 2002

Recently the laser welding technology has been applied increasingly for the automotive bodies. But the lap joint laser welding for 3 dimensional automotive body is new while the butt joint laser welding is well known as the tailored blank technology. In this study, the process window was found for the full penetration welding of the lap joint of the 1mm-thick high strength steel sheets. The limit curves and characteristic curves were suggested to define the boundaries and the contour lines in a space of the welding speed and the gap size. The characteristics of the weld sectional geometry were used to determine the limit curves. They are bead width, penetration depth and sectional area. After the observed data was analysed carefully, it was noticed that there was a transition point at which the sectional shape was changed and the bead area jumped as the welding speed was increased. Also a new concept of 'input energy Per volume' was suggested to distinguish the difference at the transition Point. The difference of sectional areas at the transition point can be related to the dynamic keyhole phenomena.

• Advances in aircraft and spacecraft science
• /
• v.5 no.5
• /
• pp.595-613
• /
• 2018

The objective of our study is to analyze the behavior of bonded, riveted and hybrid (bonded / riveted) steel / steel assemblies by tensile tests and to show the advantage of a hybrid assembly over other processes. the finite element method with the ABAQUS numerical code was used to model the fracture behavior of the different assemblies. Cohesive zone models (CZM) have been adopted to model crack propagation in bonded joints using a bilinear tensile separation law implemented in the ABAQUS finite element code. The riveted assemblies were modeled with the XFEM damage method identified in this ABAQUS numerical code. Both CZM and XFEM methods are combined to model hybrid assemblies. The results are consistent with the experimental results and make it possible to guarantee the validity of the applied numerical model. The use of a hybrid assembly shows a high resistance compared to other conventional methods, where the number of rivets has been highlighted. The use of the hybrid assembly improves mechanical strength and increases service life compared to a single lap joint and a riveted joint.

• International journal of steel structures
• /
• v.18 no.4
• /
• pp.1200-1209
• /
• 2018

In this study, a probabilistic framework of the damage assessment of pipelines subjected to extreme hazard scenario was developed to mitigate the risk and enhance design reliability. Nonlinear 3D finite element models of T-joint systems were developed based on experimental tests with respect to leakage detection of black iron piping systems, and a damage assessment analysis of the vulnerability of their components according to nominal pipe size, coupling type, and wall thickness under seismic wave propagations was performed. The analysis results showed the 2-inch schedule 40 threaded T-joint system to be more fragile than the others with respect to the nominal pipe sizes. As for the coupling types, the data indicated that the probability of failure of the threaded T-joint coupling was significantly higher than that of the grooved type. Finally, the seismic capacity of the schedule 40 wall thickness was weaker than that of schedule 10 in the 4-inch grooved coupling, due to the difference in the prohibition of energy dissipation. Therefore, this assessment can contribute to the damage detection and financial losses due to failure of the joint piping system in a liquid pipeline, prior to the decision-making.

• International journal of steel structures
• /
• v.18 no.4
• /
• pp.1284-1296
• /
• 2018

Carbon fiber reinforced polymer (CFRP), plates bonding repair method is one of the simple repair methods for cracked steel structures. In this study, the influence of width of CFRP plates on bending fatigue life of out-of-plane gusset joint strengthened with CFRP plates was investigated from the experimental and numerical point of view. In the bending fatigue test of cracked out-of-plane gusset joint strengthened with CFRP plates, the effect of width of CFRP plates on crack growth life was clarified experimentally. Namely, it was revealed that the crack growth life becomes larger with increasing the width of CFRP plates. In the numerical approach, the stress intensity factor (SIF) at the surface point of a semi-elliptical surface crack was estimated based on the linear fracture mechanics. Furthermore, the extended fatigue life of cracked out-of-plane gusset joint strengthened with CFRP plates was evaluated by using the estimated SIF at the surface point and the empirical formula of the aspect ratio of semi-elliptical crack. As the results of numerical analysis, the estimated fatigue life of the specimen strengthened with CFRP plates showed the good agreement with the test results.

• Journal of Korean Society of Steel Construction
• /
• v.24 no.2
• /
• pp.137-147
• /
• 2012

This paper describes an experimental study on the mechanical characteristic and behavior of a structure that has a joint between the reinforced concrete (RC) member and steel plate concrete (SC) member. An out-of-plane flexural test on an L-type test specimen and in-plane shear test on an I-type test specimen were carried out by means of repeated cyclic loading until their failure. Based on the results, the former showed pull-out failure mode of anchored vertical bars while the latter exhibited flexural failure mode of the basement member. These results reveal that the maximum capacity of the specimens is 96% and 82%, respectively, compared with the theoretical value.

• Journal of Korean Society of Steel Construction
• /
• v.28 no.4
• /
• pp.281-292
• /
• 2016

In this research, 10 specimens of FCAW welding with positions of 1G and 3G were tested to confirm the weldability, welding positions, and welded joint performance of 60mm HSA800 steel. The test results showed that FCAW 1G and 3G satisfied HSA800 steel's KS and the criteria for homogeneity of strength, indicating a good weld zones. However, according to the tensile test results of weld zone, 3G position FCAW welding requires improvement of welding techniques and methods.

• Journal of the Korean Society for Advanced Composite Structures
• /
• v.2 no.2
• /
• pp.13-19
• /
• 2011

This paper presents the stress distribution of the damaged butt joint of steel plate using CFRP laminates when the flange in tension zone of steel box girder is welded by butt welding. When CFRP sheets are patched on tension flange of steel-box girder, the stress distribution of a vertical and normal direction on damaged welding part is shown as parameters such as a variation of the thickness of adhesive, the overlap length with steel, and the modulus of elasticity of CFRP sheets. For the study, we wrote the computer program using the EAS(Enhanced assumed strain) finite element method for plane strain that has a very fast convergency and exact stress for distorted shape.