• Steel and Composite Structures
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• 제13권5호
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• pp.437-449
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• 2012

Concrete filled steel tube (CFST) structures have recently seen wide use in China, but studies of the shear problem of CFST are inadequate. This paper presents an experimental study on the shear capacity of circular concrete filled steel tube (CCFT) specimens with and without axial compression force. Shear capacity, ductility, and damage modes of CCFTs were investigated and compared. Test results revealed the following: 1) CCFTs with a small shear span ratio may fail in shear in a ductile manner; 2) Several factors including section size, material properties, shear span ratio, axial compression ratio, and confinement index affect the shear capacity of CCFTs. Based on test results and analysis, this paper proposes a design formula for the shear capacity of CCFTs.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 추계학술대회 논문집
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• pp.149-152
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• 2000

By using a three-dimensional finite element program HydroFORM-3D based on a rigid-plastic model, the hydroforming process for automobile subfrmae is analyzed in this study. The goal of this study is to accomplish preform design and determine the level of internal pressure for producing final hydroformed subframe component. Prior to hydroforming, the initial tube blank must be bent to the approximate centerline of the final part to enable the tube to be placed in the die cavity, After then, a preforming operation like stamping is carried out to the prebent tube. Finally, hydroforming process is performed to the preformed tube to get the final production. And through ductile fracture theory, the failure, bursting, is predicted during hydroforming process for tube blank with different diameter.

• 소성∙가공
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• 제14권9호통권81호
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• pp.779-784
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• 2005

MTS(Monobloc Tube Shaft) has been used for the reduction in weight of shaft and increase in supply of power in the auto industry nowadays. Cold drawing process having high productivity and reduction in the cost has been regarded as the effective technology that is able to substitute for swaging process as forming MTS with constant outer diameter or hollow shaft without surface defects. The objective of this study is not only to (md out the optimal process conditions understanding the effect of process parameters on carrying out cold drawing process of SIS(Steering Input Shaft) but also to control the defects resulted from inappropriate process conditions. Therefore, the proper drawing conditions are presented using FE-Analysis and experiment in the paper.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.62-65
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• 2006

This study investigated the behavior of R/C column confined with headed crossties subjected to eccentric loading. The 16 specimens are designed to have adequate confinement steel, determined by ACI seismic design. The variables studied in this research test are eccentricity to depth ratios, spacing of lateral steel and the anchor type of end of crossties. From the test results, all columns showed similar behavior up to the peak load but those columns laterally confined with head presented more ductile behavior after the peak load. The comparisons indicate that the flexural behavior of confined-concrete columns can be computed resonable accurately by P-M interaction curve.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.267-270
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• 2005

The section of double-tee is considered as one of the most efficient type for flexure. However, the depth of it is bigger then that of other slab systems. The story height of it is also increased because the duct space is required under the double tee in addition to their net depth. Thus, a new modified double-tees with the nib length of 1.58m was suggested in this study. The story height of this one is reduced up to 450mm by including duct space under the nib at the ends of slab. The four ends of the modified two single tees were designed by strut-tie models. Shear tests were performed on them to verify the safety. The ultimate shear strengths of non-prestressed two specimens were larger than the design shear strength by strut-tie models. They were failed in ductile with many distributed flexural crackings. However, the other prestressed two specimens showed much stiffer behaviors, less deflection. and strength than those of prestressed.

• Journal of Advanced Marine Engineering and Technology
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• 제33권4호
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• pp.524-532
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• 2009

In the mechanical clutches, the pressure plate is one of the important parts for transferring the power and reducing the vibration. Instead of gray and ductile irons, CGI(Compacted Graphite Cast Iron) is concerned to be the replacement recently. A thermo-mechanical coupled analysis was performed to investigate the behavior of the pressure plate for manual clutches. Thermal and mechanical properties of three kinds of cast irons were obtained from the mechanical experiments and referred other technical reports. The results of FEM analysis, were well match with the experimental ones. In this designated FEM method, temperature distribution, stress distribution and thermal deformation were successfully gained and these results will help to design the pressure plate which was made by cast irons including CGI.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1424-1430
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• 2007

Corrugated structural plate is ductile structural member which has high sectional properties compared with same thickness of plate. Corrugated plate resists the external forces by the combined action of retained soils and structures. Since it is easy to transport and assemblage of in-situ, the duration and cost of construction can be reduced. Corrugated plate structures, therefore, are widely used in culverts, hydro passages and simple bridges. RC culvert with supported by unstable soil layersin railway construction project of pohang${\sim}$samchuk has been replaced by corrugated plate culvert due to the reduction of construction duration and cost, especially the performance of behavior of settlement of ground. The structural analysis, design processes, and the economic advantages of the corrugated plate culvert are studied in this paper.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.317-322
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• 1996

The objective of this study is to investigate the characteristics of elastic and inelasitc behavior of ductile moment-resisting reinforced concrete frame subhected to reversed lateral loading such as eqrthquake excitations. For this purpose, a 2-bay 2-story R.C. plane frame with seismic detail was designed and one 1/2.5-scale subassemblage was manufactured according to the required similitude law. Then the reversed load test under the displacement control was performed statically to this subassemblage. Finally the results of this test were analysed regarding to (1) the design load vs actual strength, (2) degradation in stiffness and strength, (3) failure mode or main plastic mechanism in energy dissipation, (4) local deformations.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.397-402
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• 2003

This paper presents strut-and-tie models for predicting shear strength of RC interior beam-column joints considering the plastic hinge rotation of adjacent beams. On seismic design of frame system, it is controlled beams to occur plastic hinges and to be ductile so as to dissipate earthquake energy efficiently. The plastic hinge deformation of beams is used as analysis parameter in terms of strain of beam tensile bars at column face. The shear strengths of beam-column joints are evaluated by combining direct strut mechanism with truss mechanism. It is assumed that the max force transferred by direct strut mechanism is based on the strength of cracked concrete element, and that by truss mechanism is based on bond capacity.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.157-162
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• 2003

An experimental investigation was conducted to study the behavior of high-strength RC wide beam-column joints with slab subjected to reversed cyclic loads under constant axial load. Six half scale interior wide beam-column assemblies representing a portion of a frame subjected to simulated seismic loading were tested, including three specimens without slab and three specimens with slab. The primary variables were compressive strength of concrete($f_ck$=285, 460kgf/$cm^2$), the ratio of the column-to-beam flexural capacity($M_r$=$\Sigma M_c / \Sigma M_b$ ; 0.77 -2.26), extended length of the column concrete($l_d$ ; 0, 12.5, 30cm), ratio of the column-to-beam width(b/H ; 1.54, 1.67). Test results are shown that (1) the behavior of specimen using high-strength concrete satisfied for required minimum ductile capacity according to increase the compressive strength, (2) the current design code and practice for interior joints(type 2) are apply to the wide beam-high strength concrete column.