• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.1545-1548
• /
• 2003

In rigid-plastic finite element method, there is a heavy computation time and convergence problem. In this study. static-explicit rigid-plastic finite element method will be introduced. This method is the way that restrict the convergence interval. In result, convergence problem and computation time due to large non-linearity in the existing numerical analysis method were no longer a critical problem. Also, we investigated the effect of punch stroke and the strain increment this method. It is expected that various results from the numerical analysis will give very useful information for the design of tools in sheet metal forming process.

• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.7 s.196
• /
• pp.75-82
• /
• 2007

This paper represents a study on the development of the conceptual design for the bicycle transmission by TRIZ. At first the problem of the transmission of commercial bicycles was analyzed. The problem was defined as "the variable sprocket pitch diameter with respect to the tension change of chain". The conceptual solutions were derived by Su-Field Model Analysis, IFR(Ideal Final Result), SLP(Smart Little People), and Contradiction Matrix. The here developed sprocket prototype shows the automatic change of sprocket pitch diameter with the tension change of chain.

• Structural Engineering and Mechanics
• /
• v.57 no.6
• /
• pp.1143-1156
• /
• 2016

This paper presents a comparative study of finite element method (FEM) and analytical method for the plane problem of a layered composite containing an internal perpendicular crack in literature. The layered composite consists of two elastic layers having different elastic constants and heights. External load is applied to the upper elastic layer by means o a rigid punch and the lower elastic layer rests on two simple supports. Numerical simulations are realized by the world wide code ANYS software. Two dimensional analysis of the problem is carried out and the results are verified by comparison with solutions reported in literature. Main goal of the numerical simulation is to investigate the normal stress ${\sigma}_x$(0, y), stress intensity factors at the crack factor and the crack opening displacements.

• Advances in aircraft and spacecraft science
• /
• v.4 no.4
• /
• pp.437-448
• /
• 2017

The problem of flow through the vent is formulated as an unsteady, nonlinear, ordinary differential equation and solved using Runge-Kutta method to obtain pressure inside payload faring. An inverse problem for prediction of the discharge coefficient is presented employing measured internal pressure of the payload fairing during the ascent phase of a satellite launch vehicle. A controlled random search method is used to estimate the discharge coefficient from the measured transient pressure history during the ascent period of the launch vehicle. The algorithm predicts the discharge coefficient stepwise with function of Mach number. The estimated values of the discharge coefficients are in good agreement with differential pressure measured during the flight of typical satellite launch vehicle.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.478-484
• /
• 2009

Currently, the interests of shortage of water supply is on the rise. Even developed countries are also suffering from a drought and insufficient water supply. Likewise other countries, we do have same problem, but unfortunately we do not have any proper solution either. One of the ways suggested to settle the problem is using rain water that gets people's eyes. Rain water is evaluated such as a good way to blow the problem of water shortage out and unlimited resource. So, this study focused on the prospect of rain harvest system and possible economic effects if this system adopt in Main Stadium of Busan Asiad.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.19 no.38
• /
• pp.169-179
• /
• 1996

The object of this paper is to give an overview of one method of modeling and analysing situations involving inter-identification. Hypergame analysis is used as this approach. Hypergame analysis is one of what we call soft system approaches. In this paper, We first reformulate concept of the simple hypergame and define the hypergames with inter-identification as a system consisting of simple hypergames connected by the mutual identification. We propose a definition of solutions for them. Based on the formulation, We derives existence conditions of the solutions. We then apply the framework to a realistic problem. i. e, America-North korea conference problem to demonstrate the validity of the derived theoretical results as well as In obtain some suggestions to improve the problematic situation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.876-880
• /
• 2000

Vibration problem of deckhouse structure in a container vessel was investigated through the analysis and measurement. The natural frequency of deckhouse structure was found to be resonant with main engine 4th order excitations in the operating range, major sources of which were main engine inertial moment and axial thrust of the propulsion shafting system. To investigate and solve the problem, exciter test was performed to identify the vibration chracteristics of the ship structure and mechanical balancer was installed to compensate the 4th order inertial moment. Measurement results under the conditions with and without balancer operating were compared and analyzed to confirm the balancer effect. Good coincidence was found between the measurement and analysis results, which made it possible to predict the vibration problem in the earlier design stage.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.1945-1950
• /
• 2000

When one build a building that posses Precison production process to be sensitive to vibration and SMD to procuce a large dynamic force, how do one predict & answer vibration control problem at building structure design at first stage, That is a question. It has tried to predict dynamic response and establish answering about global or local dynamic problem in building using experimental and analysis method. One of such a try, it be proposed Semi-Empirial Method that reduce error element of input information about dynamic analysis using dynamic experimental study and measurement data in the basis of real-structure. In this paper, the dynamic response problem about RC-structure building that will be set-up SMD produce large transient dynamic force using Semi-Empirical Method.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.26 no.5
• /
• pp.602-608
• /
• 2016

The paper proposes a practical meshless method for the free vibration analysis of clamped plates having arbitrary shapes by extending the non-dimensional dynamic influence function (NDIF) method, which was developed by the author in 1999. In the proposed method, the domain and boundary of the plate of interest are discretized using only nodes without elements unlike FEM and the system matrices are obtained by making domain nodes and boundary nodes satisfy the governing differential equation and boundary conditions, respectively. However, since the above system matrices are not square ones, the problem of free vibrations of clamped plates is not reduced to an algebraic eigenvalue problem. An additional theoretical treatment is considered to produce an algebraic eigenvalue problem. It is revealed from case studies that the proposed method is valid and accurate.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.3 no.3
• /
• pp.39-45
• /
• 2004

In rigid-plastic finite element method, there is a heavy computation time and convergence problem. In this study, static-explicit rigid-plastic finite element method will be introduced. This method is the way that restrict the convergence interval. In result, convergence problem and computation time due to large non-linearity in the existing numerical analysis method were no longer a critical problem. It is expected that various results from the numerical analysis will give very useful information for the design of tools in sheet metal forming process.