• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.1
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• pp.71-77
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• 2016

In this study, the seismic performance of connections between filled composite beam (CG beams) and forming angle composite (FAC) column was experimentally evaluated. First, the bending tests were conducted on two CG beams and the axial tests were conducted on two FAC columns. Then, based on these preliminary test results, the cyclic loading test were performed on two interior connections between CG beam and FAC column. The main difference of two specimens is the plate shape of the CG beam. The test results showed that both specimens achieved the maximum story drift capacity over 0.04 radian which is required for special moment frame.

• International journal of steel structures
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• v.18 no.5
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• pp.1772-1783
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• 2018

Nowadays, the researches about composite structure system are being implemented in various fields, and many steel structures are designed based on that. In this study, the bending and seismic performance of the newly developed high-performance cold forming composite beam are evaluated by several experiments. As a result of the bending performance test, the bending moment of beam was increased stably depending on the depth and plate thickness of beam, and it is considered that the bending moment can be evaluated by the equation of a composite beam design. As a result of the seismic performance test, it was verified that sufficient seismic performance was obtained despite the increase of a negative moment rebar and depth of beam. In addition, the nominal bending moment has obtained the strength above the plastic bending moment, and also the plastic rotation angle has satisfied the requirement of composite intermediate moment frame.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.194-197
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• 2007

The dome stretching and tension test have been made to obtain a forming limit curve(FLC) for the copper alloy which is used for manufacturing the regenerative cooling chamber. For experimental survey of the forming limit curve, we have used in-plane tension specimen to obtain tension-compression strain state and also out of plane specimen to obtain tension-tension strain state through dome stretching test. All specimens are divided into longitudinal and radial direction specimens by the manufacturing method. The test results shows that in tension-tension region, copper alloy possesses a maximum major strain of 62.3% and maximum minor strain of 58.6%. In the tension-compression region, maximum major strain is 60.5% and maximum minor strain is 25.8%.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.29-36
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• 2008

In this paper, the orbital forming analysis of an automotive hub bearing was studied to predict forming performances using the explicit finite element method. To find an efficient solution technique for the orbital forming, axisymmetric finite element models and 3D solid element models were solved and numerically compared. The time scaling and mass scaling techniques were introduced to reduce the excessive computational time caused by small element size in case of the explicit finite element method. It was found from the numerical simulations on the orbital forming that the axisymmetric element models showed the similar results to the 3D solid element models in forming loads whereas the deformations at the inner race of bearing were quite different. Finally the strains at the inner race of bearing and the forming forces to the peen were measured for the same product of the numerical model by test, and were compared with the 3D solid element results. It was founded that the test results were in good agreements with the numerical ones.

• Transactions of Materials Processing
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• v.9 no.6
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• pp.670-680
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• 2000

The purpose of this study is to provide the database of forming limit diagram applicable to the warm forming of oil pan. The test materials are SCP1 and SCP3C with the thickness of 1.4mm which is used for the oil pan of automobile. The testing temperature is 5$^{\circ}C$~15$0^{\circ}C$ which is In the range of practical usage. The results are the forming limit diagram limiting dome height and the maximum punch load at each temperature such as 5$^{\circ}C$, $25^{\circ}C$, 6$0^{\circ}C$, 9$0^{\circ}C$, 12$0^{\circ}C$ and 15$0^{\circ}C$. From these results, we can see that the forming limit curves are translated depending upon the temperature and that FLC at low temperature is higher than at high temperature. Both of limiting dome height and maximum punch load also decrease as the temperature increases. Present results can be useful for die trial and forming analysis as a tool of evaluating the forming severity for the sheet metal forming processes at the warm working condition by comparing the practical strains with FLC.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.121-126
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• 2011

An accumulator placed on the refrigerant cycle pipe lines is a part to relax fluctuations of pressure within the pipe lines and stabilize refrigerants flowed into pipe. The accumulator has been mainly manufactured by the process of tube spinning using CNC(Computer Numerical Control) lathe. However, this process has the defects which are low productivity per hour and high cost. For that reason, tube end-forming using roll die is actively being developed, recently. The purpose of this study is to develope the tube end-forming process using roll die in order to manufacture the accumulator for the refrigeration pipe lines. First, the process design of tube end-forming was performed based on specification of product, and then was verified with FE analysis. Also, the effects of friction coefficient and revolution speed of roll die on forming load were investigated. The analytical results were applied in the final process design of tube end-forming. Finally, tube end-forming test was carried out to verify the validity of the FE analysis and the process design.

• Journal of Power System Engineering
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• v.17 no.3
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• pp.65-71
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• 2013

The under rail slide is the latest device to make accurate rectilinear reciprocating motion. In these day, 3-point type is used mostly for the products requiring high strength and performance such as refrigerator door guide or furniture drawer guide. However, It is all imported from foreign countries due to lack of the roll forming technique to make 3-point type under rail slide in domestic. Therefore, design and manufacturing technology for the 3-point type under rail slide are need to development through systematic study. In this paper, to make center member of 3-point ball-type under rail slide for the refrigerator doors, the roll forming modeling and simulation are performed using Shape-RF software. Tensile test is performed about SCP-1 1/2H for determine the mechanical properties of materials. Interference between the roll and the final shape are predicted from the results of the simulation ; this result show that the desirable performance and usefulness of the designed roll forming process.

• Geomechanics and Engineering
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• v.27 no.6
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• pp.573-582
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• 2021

From the effect of bound water, this study aims to seek the potential reasons for difference of mechanical experiment results of subgrades soils. To attain the comparatively test condition of bound water, dry forming (DF) and wet forming (WF) were used in the specimen forming process before testing, series of laboratory tests, i.e., CBR tests, direct shear tests and compaction tests. The measured optimal moisture contents, maximum dry densities, CBR, cohesion c, and internal friction angle 𝜑 were given contrastive analysis. Then to detect the adsorptive bound water in the subgrade soils, the thermal gravimetric and differential scanning calorimetry (TG-DSC) test were employed under different heating rates. The free water, loosely bound water and tightly bound water in soils were qualitatively and quantitatively analyzed. It was found that due to the different dehydration mechanics, the lost bound water in DF and WF process show their own characteristics. This may lead to the different mechanical properties of tested soils. The clayey particles have a great influence on the bound water adsorbed ability of subgrade soils. The more the clay content, the greater the difference of mechanical properties tested between the two forming methods. Moreover, in highway construction of southern China, the wet forming method is recommended for its higher authenticity in simulating the subgrade filed humidity.

• Composites Research
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• v.23 no.6
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• pp.55-60
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• 2010

In this paper, tensile and bending tests of glass/polypropylene composite (Twintex) specimens fabricated by various forming conditions were carried out and the results were compared according to the forming conditions to find the appropriate condition for the forming composite bone plates. From the tests it was found that the most appropriate forming conditions were $230^{\circ}C$, 3MPa. Composite bone plates were formed using this condition by two different fabricating methods for screw holes: one was a net shape molding and the other was drilling. The forming and bending tests revealed that the drilling process provided much better bending stiffness of bone plates. This paper provided the most appropriate condition for forming composite bone plates and this result was also expected to offer informative data on forming of other Twintex structures.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10b
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• pp.36-39
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• 2003

Due to the strength and biocompatibility requirement, the stainless steel SUS 316L is widely used for trauma internal fixation device. SUS 316L can be hardened and strengthened only by cold work. In this work, the material compression test is performed both in laboratory and computer simulation by a FEM analysis software DEFORM to correlate the hardness to strain. This data is then used for preform design and predict the hardness of the finish bone plate forging. Finally, we compared the hardness between the actual forging and computer analysis results. Although the predicted hardness from computer simulation. is 55HV higher than the final forging sample, we can get good compatibility on the hardening tendency of cold forging.