• Journal of the Earthquake Engineering Society of Korea
• /
• v.7 no.3
• /
• pp.47-55
• /
• 2003

This study proposed a convenient seismic design procedure for buckling-restrained braced frames based on the equivalent energy concept. The design process begins with the computation of input energy from response spectrum. Then the elastic energy and plastic energy are computed based on the equal energy concept. The computed plastic energy is distributed to each story along energy distribution ratio and the cross-sectional area of each brace is computed so that all the plastic energy is dissipated by the brace. The proposed procedure was applied to the design of three-, six-, and twenty-story steel frames with buckling-restrained braces, and artificial earthquake records were used for verification of the proposed method. According to analysis results, top story displacements of the low-rise structure satisfies the given target displacement however that of the twenty-story structure was much smaller than the given target displacement.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.03a
• /
• pp.45-48
• /
• 1999

The optimal blank design method by sensitivity analysis has been applied to the formings of oil-pan, tailored blank and front panel have been chosen as the examples. Die shape is prepared by a commercial CAD system. Excellent results has been obtained between the numerical results and the target contour shapes. Through the investigation, the proposed systematic method of optimal blank design is found to be effective in the practical forming processes.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1998.03a
• /
• pp.113-116
• /
• 1998

A derivative based approach to process optimal design in powder forging is presented. The process model, the formulation for process optimal design, and the schemes for the evaluation of the design sensitivity, and an iterative procedure for the optimization are described in detail. The validity of the schemes for the evaluation of the design sensitivity is examined by performing numerical tests. The capability of the proposed approach to deal with diverse process parameters and objective functions is demonstrated through applications to some selected process design problems.

• Transactions of Materials Processing
• /
• v.6 no.6
• /
• pp.489-499
• /
• 1997

The injection molding process is analyzed to get the information on the mold design parameters and the optimum process conditions for automotive plastic front fender. The gate position, runner size and cooling channel are determined by the estimation of the flow balance, packing time, uniform cooling and shrinkage and warpage in the injection molding analyses. The procedure can be used in the mold design in the early stage when developing plastic parts.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2005.10a
• /
• pp.312-317
• /
• 2005

In this study, using the stamping, analysis program, PAM STAMP, applied to the drawing result of springback analysis and draw analysis with applying on the best design planning as many times simulations from the initial stage of the die developing of automotive panels. Especially, after inspecting the design method with stamping analysis and springback analysis, write about the die development examples, using CADCEUS which is the software revising the amount of springback.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.8 no.3
• /
• pp.131-140
• /
• 2004

The main objective of the research is to develop an algorithm for the optimum design of two dimensional steel frames using refined plastic hinge analysis which considers material and geometrical nonlinearities. Using developed algorithm, an optimum design was perform without calculating an effective length factor of the column (K-factor). A multi-level discrete optimization technique with two parameters has been developed and employed in the optimum design algorithm. The optimization algorithm is applied to structural design with the objective of minimizing the weight of a structure and with constraints on load limit, frame drift, ductility. Various application example is provided to demonstrate the feasibility, validity and efficiency of the developed program.

• Journal of Korean Society of Steel Construction
• /
• v.16 no.1 s.68
• /
• pp.21-32
• /
• 2004

In this study, a continuous optimum design model with its application program for plane steel frame structures developed. In the model, the sequential unconstrained minimization technique (SUMT) transforming the nonlinear optimization problem with multidesign variables and constraints into an unconstrained minimization problem and the refined plastic hinge analysis method as one of the most effective second-order inelastic analysis methods for steel frame structures were implemented. The total weight of a steel frame structure was taken as the objective function, and the AISC-LRFD code requirements for the local and member buckling, flexural strength, shear strength, axial strength and size of the cross-sectional shapes of members were used for the derivation of constraint equations. To verify the appropriateness of the present model, the optimum designs of serveral plane steel frame structures subject to vertical and horizontal loads were conducted.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.3
• /
• pp.732-737
• /
• 2016

Using the pyrolyzed carbon black (PCB) from waste tires, the performance of 13 mm dense-graded hot mix asphalt was evaluated. The Marshall mix design was carried out and the measured optimal asphalt content was 5.8%. The impact resonant test was conducted to obtain the elastic modulus and damping ratio of the hot mix asphalt. The elastic modulus of HMA increased with increasing amount of PCB. On the other hand, there was no significant change in the damping ratio. The Marshall mix design, indirect tensile test, permanent deformation test, and program analysis were carried out. The strength ratio of the PCB modified asphalt mixtures was within 10%. More 10% of PCB was not good for the permanent deformation of hot mix asphalt. From the pavement design program, the use of 5% PCB in hot mix asphalt showed a decrease in the top-down crack, bottom-up crack, and permanent deformation. Judging from the limited test and analysis, the use of 5% PCB is good for enhancing the pavement performance.

• Geotechnical Engineering
• /
• v.13 no.4
• /
• pp.85-94
• /
• 1997

The design and construction of underground structures contain many substantial mincer dainties. A reasonable estimation of geotechnical parameters is of paramount importance and must be one of the most difficult tasks in designing and constructing underground structures. If the plastic zone exists by tunnel excavation, the ground response may also be dependent on the yield criterion mainly composed of strength parameters. In order to estimate unknown model parameters from the in-situ measurements as well as prior estimates for designing tunnels which have plastic zones, the Extended Bayesian Method(EBM) is adopted : an elasto-plastic finite element program is linked to the EBM as a mathematical model to predict the ground response. Mohr-Coulomb failure criterion is used to represent the plastic behavior. A hypothetical underground site, where the ground behaves elasto-plastically, is adopted to demonstrate the validity of the proposed feedback system.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1996.03b
• /
• pp.121-129
• /
• 1996

This study aimsdetecting defects for the forming precesses of X2 spline, which is designed by an industry expert. The exist process consists of 3 runs and 7 operations with 3 heat treatments. The rigid-plastic FEM analysis was carried out to design a new process and some defects were found. Thus the design was modified to get better results. it is ocnfirmed that the industry expert agree the possibility of defects derived from the FEM results.