• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.14 no.3
• /
• pp.361-369
• /
• 2001

This paper deals with numerical efficiency of nonlinear solution technique for space trusses. It will propose the combined Arc-length method to trace structural behavior after reaching buckling load as opposed to the current Arch-length method. The combined Arc-length method uses the current stiffness parameter as a control variable. It uses Secant-Newton method in stable path and applies Arc-length method in unstable path. To evaluate efficiency of solution technique, the accuracy of solution, convergence, and computing time concerning illustrative numerical examples are compared with the current Arc-length method. It show that the combined Arc-length method, as proposed in this paper, is superior to the current Arc-length method in numerical nonlinear analysis.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.20 no.6
• /
• pp.691-697
• /
• 2007

Numerical eigen analysis of beam-like structure can be easily and effectively done by various conventional beam theory-based methods. However, in case of the structures composed of composite-sectioned beams, the application of conventional numerical methods requires one to derive both equivalent material and geometry properties. In the present paper, these equivalent properties are derived by the transformed section method and the test FEM program is coded. The numerical accuracy of the proposed method is verified through the comparison with the ANSYS 3-D model.

• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.277-282
• /
• 2006

In order to predict the indoor air pollutant, the VOCs emission rate is used through small chamber in the design process. However, the small chamber method has limitations as the convective mass transfer coefficient, the most important factor when predicting VOCs contamination of indoor air, is different between the small chamber result and the measured data in the actual building. Furthermore, the existing studies which analyzed mass transfer coefficient in the small chamber were directed on the small chambers developed at the time and FLEC(Field and Laboratory Emission Cell), thus, are different from the current small chamber which has been changed with improvements. The purpose of this study is to determine the emission rate of pollutant in double-layered building materials through the CFD(Computational of Fluid Dynamics) and Numerical analysis based on the mass transfer coefficient on singled-layered building material by using the current small chamber widely used in Korea. Futhermore, this study used the new convective mass transfer coefficient($h_m'$) which indicates the existing convective mass transfer coefficient($h_m$) including VOC partition coefficient(k). Also, formaldehyde was selected as target pollutant.

• The Journal of Engineering Geology
• /
• v.33 no.3
• /
• pp.439-459
• /
• 2023

Numerical analysis has been adopted in nearly all modern scientific and engineering fields due to the rapid and ongoing evolution of computational technology, with the number of grid or mesh points in a given data field also increasing. Some values must be extracted from large data fields to evaluate and supplement numerical analysis results and observational data, thereby highlighting the need for a fast and effective interpolation approach. The quadrilateral irregular network (QIN) proposed in this study is a fast and reliable interpolation method that is capable of sufficiently satisfying these demands. A comparative sensitivity analysis is first performed using known test functions to assess the accuracy and computational requirements of QIN relative to conventional interpolation methods. These same interpolation methods are then employed to produce simple numerical model results for a real-world comparison. Unlike conventional interpolation methods, QIN can obtain reliable results with a guaranteed degree of accuracy since there is no need to determine the optimal parameter values. Furthermore, QIN is a computationally efficient method compared with conventional interpolation methods that require the entire data space to be evaluated during interpolation, even if only a subset of the data space requires interpolation.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2000.04b
• /
• pp.111-118
• /
• 2000

Concrete cracking due to the temperature gradient across the wall, caused by the difference in temperature between cryogenic liquid natural gas stored and surrounding environment of in-ground LNG storage tank, is investigated in this study. Crack propagation of concrete LNG tank is effectively simulated by using a layered degenerated shell element. In addition, material nonlinearity is taken into consideration on the basis of the nonlinear elastic-orthotropic model. Finally, numerical analysis for a real LNG storage tank is conducted with the objective to verify the efficiency of the introduced model.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2004.04a
• /
• pp.73-80
• /
• 2004

Mass matrix, elastic stiffness matrix, load correction stiffness matrix by circulatory non-conservative force, and Winkler and Pasternak foundation matrix of framed structure in 2-D are calculated for stability analysis of divergence or flutter system. Then, a matrix equation of the motion for the non-conservative system is formulated and numerical results are presented to demonstrate the effect of some parameters with using Newmark method.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.6
• /
• pp.745-756
• /
• 2003

An analysis of wind environments using computational fluid dynamics and an evaluation of wind resources using measurement data obtained from meteorological observation sites at Homi-Cape, Pohang have been carrid out for siting a wind farm. It was shown that a numerical simulation using computational fluid dynamics would provide reliable wind resource map in complex terrain with land-sea breeze condition. As a result of this investigation, Homi-Cape wind farm with 11.25 ㎿ capacity has been designed for maximum power generation and 25.7 GWh electricity production is predicted.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1999.04a
• /
• pp.245-251
• /
• 1999

As the crack grows in the residual stress fields, the distribution of the residual stress is changed. In this study, a finite element modeling technique is developed to simulate the redistribution of residual stress due to crack propagation. To certify the accuracy, the crack propagation tests were carried out and tile effective stress intensity factor range was evaluated considering the redistribution of residual stress from the FE analysis.

• Computational Structural Engineering
• /
• v.8 no.1
• /
• pp.123-126
• /
• 1995

The purpose of the analysis is the numerical simulation of structures strained to the limit loads. The finite element calculations and experiments with cracked structures have been carried out yielding over limit strains between 10% and 15% by single peak load. Load versus displacement-diagrams and J-diagrams up to the limit load are calculated. By this way the influence of geometric parameters may be assessed in the post yield region. It is proposed to use such calculations to correlate experiments carried out with small specimens to experiments simulating the true dimensions of the design structure.

• Computational Structural Engineering
• /
• v.8 no.2
• /
• pp.141-145
• /
• 1995

This paper deals with a time-domain boundary element technique suitable for the analysis of linear viscoelastic materials in the presence of transient temperature field. Thermorheologically simple behavior has been assumed. Following an exposition of the boundary element formulation, the numerical results of example problem have been presented.