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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Transactions of Materials Processing
Journal Basic Information
Journal DOI :
The Korean Society for Technology of Plasticity
Editor in Chief :
Volume & Issues
Volume 23, Issue 8 - Dec 2014
Volume 23, Issue 7 - Nov 2014
Volume 23, Issue 6 - Oct 2014
Volume 23, Issue 5 - Aug 2014
Volume 23, Issue 4 - Jul 2014
Volume 23, Issue 3 - Jun 2014
Volume 23, Issue 2 - Apr 2014
Volume 23, Issue 1 - Feb 2014
Selecting the target year
A Study of the Broach Tool Shape for Improving Concentricity of a T/F Driven Gear
Park, S.J. ; Kim, D.H. ;
Transactions of Materials Processing, volume 23, issue 5, 2014, Pages 275~281
DOI : 10.5228/KSTP.2014.23.5.275
Broaching is widely used for the machining of inner shaped slots in work-pieces. The broach tool is moved vertically (usually by hydraulic power) through the work-piece. Broaching occurs with the work-pieced fix while the broach tool traverses through material and shears it. To produce a T/F driven gear both an outside cutting and an inside cutting are needed. The outside cut determines the tooth profile and the inside cut determines the inner dimension. Broaching can cause problems with concentricity. In the current study, the characteristics of shearing along the cutting blade and the broaching of a T/F driven gear are considered.
A Study on the Effect of Pin Height on Weld Strength in Extru-Rivet Spot Welding of Aluminum Plates
Lee, S.J. ; Kim, T.H. ; Jin, I.T. ;
Transactions of Materials Processing, volume 23, issue 5, 2014, Pages 282~288
DOI : 10.5228/KSTP.2014.23.5.282
It is difficult to control welding variables during spot welding of non-ferrous metals like aluminum because of the low electrical resistance of the material. It has been suggested that a solid state welding process such as friction stir spot welding or extru-spot welding can be used to spot weld aluminum plates. In the extru-spot welding, there is a need to increase the weld strength by improving the shape of the welding die. The current study shows that the weld strength for an extru-spot welding can be increased by using a pin placed on the inside of the upper electrode in the welding die. In the current study, the deformed shape of the insert rivet and the stress distribution in the welding zone were analyzed by simulation. Extru-rivet spot welding experiments were performed by changing the height of pin on the inside of the upper electrode. From the experimental result, it is shown that the weld strength for an extru-rivet spot welding can be increased by adjusting the height of the pin. The optimal shape of the deformed rivet after the extru-rivet spot welding can be observed from the simulation results. The deformed shape of the insert rivet can also be controlled by the height of pin.
Analytical Study for the Prediction of Mechanical Properties of a Fiber Metal Laminate Considering Residual Stress
Kang, D.S. ; Lee, B.E. ; Park, E.T. ; Kim, J. ; Kang, B.S. ; Song, W.J. ;
Transactions of Materials Processing, volume 23, issue 5, 2014, Pages 289~296
DOI : 10.5228/KSTP.2014.23.5.289
Uniaxial tensile tests were conducted to accurately evaluate the in-plane mechanical properties of fiber metal laminates (FMLs). The FMLs in the current study are comprised of a layer of self-reinforced polypropylene (SRPP) sandwiched between two layers of aluminum alloy 5052-H34. The nonlinear tensile behavior of the FMLs under in-plane loading conditions was investigated using both numerical simulations and a theoretical analysis. The numerical simulation was based on finite element modeling using the ABAQUS/Explicit code and the theoretical constitutive model was based on the volume fraction approach using the rule of mixture and a modification of the classical lamination theory, which incorporates the elastic-plastic behavior of the aluminum alloy and the SRPP. The simulations and the model are used to predict the inplane mechanical properties such as stress-strain response and deformation behavior of the FMLs. In addition, a post-stretching process is used to reduce the thermal residual stresses before uniaxial tensile testing of the FMLs. Through comparison of both the numerical simulations and the theoretical analysis with the experimental results, it is concluded that the numerical simulation model and the theoretical approach can describe with sufficient accuracy the actual tensile stress-strain behavior of the FMLs.
Application of Springback Analysis in the Development of a Reinforce Center Pillar Stamping Die
Kim, K.T. ; Kim, S.H. ; Yoo, K.H. ; Lee, C.W. ; Shim, H.B. ;
Transactions of Materials Processing, volume 23, issue 5, 2014, Pages 297~302
DOI : 10.5228/KSTP.2014.23.5.297
The current paper introduces work that was conducted during the development of a stamping die for a reinforce center pillar made from high strength steel. In the current study, the Bauschinger effect on the springback analysis was studied by comparing simulation results with real panels, which are currently in production. For a complicated part shape, quantitative measurements of the deformed shape are not easy in general to obtain. An adjustment procedure of the shape data for some chosen sections has been suggested to improve the accuracy of the quantitative measurements. The results show that the kinematic hardening model provides more accurate results.
Functionally Graded Properties Induced by Direct Laser Melting of Compositionally Selected Metallic Powders
Han, S.W. ; Ji, W.J. ; Lee, C.H. ; Moon, Y.H. ;
Transactions of Materials Processing, volume 23, issue 5, 2014, Pages 303~310
DOI : 10.5228/KSTP.2014.23.5.303
Functionally graded properties are characterized by the gradual variation in composition and structure through the volume of the material, resulting in corresponding gradation in properties of the material. Direct laser melting (DLM) is a prototyping process whereby a 3-D part is built layer-wise by melting metal powder with laser scanning. Studies have been performed on the functionally graded properties induced by direct laser melting of compositionally selected metallic powders. For the current study, quadrangle structures were fabricated by DLM using Fe-Ni-Cr powders having variable compositions. Hardness and EDX analysis were conducted on cross-sections of the fabricated structure to characterize the properties. From the analysis, it is shown that functionally graded properties can be successfully obtained by DLM of selected metallic powders with varying compositions.
Finite Element Analysis of the R-value of a 2-Layer Clad Steel
Kim, J.G. ; Park, B.H. ; Kim, S.K. ; Chin, K.G. ; Kim, H.S. ;
Transactions of Materials Processing, volume 23, issue 5, 2014, Pages 311~316
DOI : 10.5228/KSTP.2014.23.5.311
In the current study, the R-value behavior of a two-layer clad steel was investigated using finite element analysis. Hill's 1948 anisotropic yield equation was employed to characterize the anisotropic behavior of the steel with different assumed properties: isotropic (R=1) and anisotropic (R=2). Experimental R-values were determined by measuring the width and thickness ratios of tensile specimens. Finite element analysis results demonstrate a difference in strain behavior in the width and the thickness directions of the clad steel. The R-value behavior depends on the fraction of the clad materials and total elongation.
Enhancement of Hydroformability Through the Reduction of the Local Strain Concentration
Shin, S.G.R. ; Joo, B.D. ; Moon, Y.H. ;
Transactions of Materials Processing, volume 23, issue 5, 2014, Pages 317~322
DOI : 10.5228/KSTP.2014.23.5.317
Bursting during tube hydroforming is preceded by localized necking. The retardation of the initiation of necking is a means to enhance hydroformability. Since high strain gradients occur at the necking sites, a decrease in local strain gradients is an effective way to retard the initiation of necking. In the current study, the expansion at potential necking sites was intentionally restricted in order to reduce the strain gradient at potential necking sites. From the strain distribution obtained from FEM, it is possible to determine strain concentrated zones, which are the potential necking sites. Prior to the hydroforming of a trailing arm, an incompressible material(such as lead) is attached to the tube where the strain-concentrated zone would contact the die. Due to the incompressibility of lead, the tube expansion is locally restricted, and the resultant strain extends to adjacent regions of the tube during hydroforming. After the first stage of hydroforming, the lead is removed from the tube, and the hydroforming continues to the final targeted shape without any local restriction. This method was successfully used to fabricate a complex shaped automotive trailing arm that had previously failed during traditional hydroforming fabrication.