• Journal of the Korean Society for Precision Engineering
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• v.13 no.2
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• pp.185-193
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• 1996

Errors included in solutions obtained by the boundary element method are generally larger than those by the finite element method in the case that the number of discreted elements is small. One of the reasons is supposed to be attributed to the error which will be produced in the numerical integration of the singular functions in two dimensional elastic problem. Then, treatment of analytical integration to reduce computing time and to decrease errors of boundary element method are proposed.

• Wind and Structures
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• v.25 no.4
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• pp.329-342
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• 2017

This work presents a static and free vibration analysis of functionally graded metal-ceramic (FG) beams with considering porosities that may possibly occur inside the functionally graded materials (FGMs) during their fabrication. A new displacement field containing integrals is proposed which involves only three variables. Based on the suggested theory, the equations of motion are derived from Hamilton's principle. This theory involves only three unknown functions and accounts for parabolic distribution of transverse shear stress. In addition, the transverse shear stresses are vanished at the top and bottom surfaces of the beam. The Navier solution technique is adopted to derive analytical solutions for simply supported beams. The accuracy and effectiveness of proposed model are verified by comparison with previous research. A detailed numerical study is carried out to examine the influence of the deflections, stresses and natural frequencies on the bending and free vibration responses of functionally graded beams.

• Korean Institute of Interior Design Journal
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• no.4
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• pp.31-36
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• 1995

The purpose of this studies on the interior environment of the apartments, this study has purported to identify basic elements constituting an appropriate and comfort-able interior environment. For analytical purposes, prelim-inary and main investigation have been implemented, and the questionnaire survey has been conducted on the apartments constructed in the metropolitan area and five new satellite cities as the objects of evaluation and se-lected as the analytical object. After analyses of the cor-relation between dweller's and Interior spaces condition, the conclusion is as follows; There should be conducted systematic and comprehensive inspections of apartments no only centering around the occupants but also the ob-jective evaluation of environment and functions of the apartments.

• Computers and Concrete
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• v.26 no.5
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• pp.421-427
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• 2020

In this study, the two-dimensional generalized finite integral transform(FIT) approach was extended for new accurate thermal buckling analysis of fully clamped orthotropic thin plates. Clamped-clamped beam functions, which can automatically satisfy boundary conditions of the plate and orthogonality as an integral kernel to construct generalized integral transform pairs, are adopted. Through performing the transformation, the governing thermal buckling equation can be directly changed into solving linear algebraic equations, which reduces the complexity of the encountered mathematical problems and provides a more efficient solution. The obtained analytical thermal buckling solutions, including critical temperatures and mode shapes, match well with the finite element method (FEM) results, which verifies the precision and validity of the employed approach.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.2
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• pp.91-99
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• 1998

This paper presents a methodology for identifying the cutter runout geometry in end milling process. Cutter runout is common but undesirable phenomenon in multi-tooth machining because it introduces variable chip loading to insert which results in a accelerated tool wear. amplification of force variation and hence enlargement vibration amplitude From understanding of chip load change kinematics, the analytical cutting force convolution model was formulated as the angular domain convolution model was formulated as the angular domain convolution of three dynamic cutting force component functions. By virtue of the convolution integration property, the frequency domain expression of the local cutting forces and the chip width density of the cutter. Experimental study is presented to validate the analytical model. This study provides the in-process monitoring and compensation of dynamic cutter runout to improve machining tolerance and surface quality for industrial application.

• Computers and Concrete
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• v.15 no.2
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• pp.199-213
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• 2015

The residual fracture toughness of post-fire normal-strength concrete subjected up to $600^{\circ}C$ is considered by the wedge splitting test. The initial fracture toughness $K_I^{ini}$ and the critical fracture toughness $K_I^{un}$ could be calculated experimentally. Their difference is donated as the cohesive fracture toughness $K_I^c$ which is caused by the distribution of cohesive stress on the fracture process zone. A comparative study on determining the residual fracture toughness associated with three bi-linear functions of the cohesive stress distribution, i.e. Peterson's softening curve, CEB-FIP Model 1990 softening curve and Xu's softening curve, using an analytical method is presented. It shows that different softening curves have no significant influence on the fracture toughness. Meanwhile, comparisons between the experimental and the analytical calculated critical fracture toughness values further prove the validation of the double-K fracture model to the post-fire concrete specimens.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.175-182
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• 1998

An analytical study to trace the nonlinear structural behavior of composite beams is undertaken to include the nonlinear material properties of steel sheeting, reinforcing steel bar and concrete. To trace Moment-curvature relations, sectioning analysis method and two simple formulas are developed. A simple power model which has been originally used to expect the flexural capacity of the beam to column connections is proposed and the second formula is composed of two experimental functions to express the Moment-curvature relation in the elastic and plastic range separately. The load-deflection behavior of the beams has been simulated by the step-by-step numerical integration method and is compared with the test results available.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.267-274
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• 2001

In this paper, a analytical model which can simulate the post-cracking behavior and tension stiffening effect in a reinforced concrete(RC) tension member is proposed. Unlike the classical approaches using the bond stress-slip relationship or the assumed bond stress distribution, the tension stiffening effect at post-cracking stage is quantified on the basis of polynomial strain distribution functions of steel and concrete, and its contribution is implemented into the reinforcing steel. The introduced model can be effectively used in constructing the stress-strain curve of concrete at post-cracking stage, and the loads carried by concrete and by reinforcing steel along the member axis can be directly evaluated on the basis of the introduced model. In advance, the prediction of cracking loads and elongations of reinforced steel using the introduced model shows good agreements with results from previous analytical studies and experimental data.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.674-679
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• 1998

In designing the prestressed concrete box-bridge, the dead load, prestressing force, creep and shrinkage of concrete are the main factors which influence the camber and deflection of segmental concrete structure under construction. Among these factors the creep and shrinkage are the functions of the time-dependent property which, therefore, must be considered with time. The prediction model for estimating creep and shrinkage of concrete has been suggested by ACI, CEB/FIP, JSCE and KSCE design code and EMM, AEMM, RCM, IDM and SSM has been suggested for analytical method in consideration of the time-dependent characteristics. In this study, the creep test was carried out for four curing ages of concrete which were applied to the prestressed concrete structure at a construction site, and the results of test were compared to the values of creep prediction by the design code. Also the creep test of step-wise incremental stresses were performed and were compared to analytical methods.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.12
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• pp.43-50
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• 1993

Three-dimensional simulator for the ion implantation process is developed. The simulator based on an analytical model which would be a choice with high computational efficiency and accuracy. This is an important issue for the simulation of a numerous number of processing steps required in the fabrication of ULSI or GSI. The model can explain scattering and bulk channeling mechanism (1D). It can also explain depth dependent lateral diffusion effect(2D) and mask effect(3D). The model is consist of one-dimensional JPD(Joined Pearson Distribution) function and two-dimensional modified Gaussian functions. Final implanted profiles under typical mask structures such as hole, line and island structure are obtained with varying ion species.