• Computers and Concrete
• /
• v.17 no.3
• /
• pp.305-322
• /
• 2016

The work is intended to demonstrate that the loss of bond between concrete and flexural steel which led in recent years a number of flat-slab structures to punching collapse under service loading conditions is also relevant to ultimate limit-state design. It is based on a comparative study of the results obtained from numerical experiments on flat slab-column sub-assemblages. The slabs were designed for punching either in compliance with the EC2 code requirements, which do not allow for such loss of bond, or in accordance with the compressive force-path method which considers the loss of bond between concrete and the flexural reinforcement in tension as the primary cause of punching. The numerical experiments are carried out through the use of a nonlinear finite element analysis package for which, although ample published evidence of its validity exists, additional proof of its suitability for the purposes of the present work is presented.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1996.10a
• /
• pp.202-209
• /
• 1996

In this paper, two dimensional vertical and comer infinite elements which can include multiple wave components to model underlying half space are developed. These elements are natural and economical to model underlying stiff half space or rock. To verify the behavior of these infinite elements, vertical, horizontal, and rocking compliances of a rigid strip foundation on a viscoelastic soil profile are analyzed and compared with those of Tzong and Penzien who used the boundary solution method. Good agreements are noticed between the two methods. The influence of material properties like Poisson's ratio, material damping, and stiffness ratio of layers as well as the influence of geometrical properties such as layer thicknesses and depth of foundation embedment are studied. Example analysis is carried out for the shaking table which is located in KIMM(Korea Institute of Machinery and Materials), and the vertical and horizontal displacements of the analysis are compared with the measured, and show good results and demonstrate the efficiency of the proposed method.

• Journal of Mechanical Science and Technology
• /
• v.18 no.2
• /
• pp.253-261
• /
• 2004

A simple and effective filtering method to control the member size of an optimized structure is proposed for topology optimization. In the present approach, the original objective sensitivities are replaced with their relative values evaluated within a filtering area. By adjusting the size of the filtering area, the member size of an optimized structure or the level of its topological complexity can be controlled even within a given finite element mesh. In contrast to the checkerboard-free filter, the present filter focuses on high-frequency components of the sensitivities. Since the present filtering method does not add a penalty term to the objective function nor require additional constraints, it is not only efficient but also simple to implement. Mean compliance minimization and eigenfrequency maximization problems are considered to verify the effectiveness of the present approach.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.03a
• /
• pp.220-226
• /
• 1998

In this pater, a method of strength evaluation applying fracture mechanics in adhesively bonded joints of A1/A1 materials was investigated. Various adhesively bonded joints of double-cantilever beam with a interfacial crack in its adhesive layer were prepared for the fracture toughness test of comprehensive mixed mode conditions from nearly pure mode I to mode II. The experiment of fracture toughness was carried out under various mixed mode conditions with an interfacial crack and critical energy release rate, Gc by the experimental measurements of compliances was determined. From the results, fracture toughness on mixed mode with an interfacial crack is well characterized by strain energy release rate and a method of strength evaluation by the fracture toughness in adhesively bonded joints of A1/A1 materials was discussed.

• Journal of the Korea Safety Management & Science
• /
• v.10 no.4
• /
• pp.93-104
• /
• 2008

A successful fire risk assessment is depends on identification of risk, the analytical process of potential risk, on estimation of likelihood and the width and depth of consequence. Take the influence on enterprise into consideration, Fire risk assessment could carry out along the evaluation of the risk importance, the risk level and the risk acceptance. A large part of the limitation of choosing the risk assessment techniques impose restrictions on expense and time. If it is unnecessary high level risk assessment or Probabilistic Risk Assessment of buildings, in compliance with the Relative Ranking Method, Fire risk indexing and assessing is possible. As working-level technique, AHP method is useful with practical technique.

• Proceedings of the KIEE Conference
• /
• 2007.10a
• /
• pp.141-142
• /
• 2007

The world-wide various nations is doing the development competition of marine resources for solving supply and non balance of the resources in compliance with depleting the land resources. Currently for exploring marine resources, After confirming the location of the resources by controlling search equipment and sensor module in research vessel, the method which collects sample of searched resources and analyzes the quality and a contents of the resources in research vessel is been applying. This search method is structure which analyzes an ingredient in ship and decides the quality of the resources. And real-time processing for an effective resources search is been demanding. Therefore in this paper, we have developed a resources identification algorithm that can display the type feature of resources by real-time 3D Graphic.

• 전기의세계
• /
• v.25 no.1
• /
• pp.87-94
• /
• 1976

The characteristic of flashover electric discharge has been brought to light in this paper for the situation in which the space and creeping gaps are laid out in series. The result of this study has disclosed the facts that the over all flashover characteristics have three kind of features such as unilateral increase after increase, and increase after decrease in compliance with varied layout method and relative magnitude of gap length, and accordingly there exist a ratio among the magnitudes of gap length and a proper layort method through which the over all flashover voltage reaches the highest. Also involved with this study is the theoretic analysis of flashover characteristics even in the case of creeping electric discharge from hand tip of the gauge, where the over all value of flashover voltage can be estimated from the peculiar value of flashover voltage and flicker voltage for the space and creeping gap within the extent of 5% error.

• Journal of the Korean Society for Precision Engineering
• /
• v.4 no.1
• /
• pp.65-73
• /
• 1987

In recent days, the application of ultrasonics has been increased in the field of engineering and medicine. The ultrasonic hardness tester to apply the principle of contact compliance method is entirely different from hardness tester in the past and in the practical use, the more pre- cisive measurement is required because it has a slight change of hardness value due to the difference of resonance frequency. Therefore, in this study, as one type of applicative transducers which can detect the optimum pressure load, ring type load cell was used in the measurement of ultrasonic hardness. From experimental results, it was compared ultrasonic hardness testing method with the other hardness testing methods. Also, the measurement error of ultrasonic hardness tester could be measured within .+-. 0.5 HRC F.S. in the case of 3.0Kg pressure load.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.258-263
• /
• 2005

The nearest variety of the industrial world requires using the high precision and resolution positioning technology to do a semi-conductor, information field , and measurement field. It is especially important for the positioning technology that makes up a proper controller, is affected by the minimal heat and vibration, and can control a structurally generated non-linear friction factor to determine the efficiency of the system. The paper is to analyze the vibration characteristic according to the speed of linear motor and grasp the dynamic characteristic through the modal test and show the verification of the experimental result and design parameters by using FEM(Finite Element Method). Also, it shows the optimum standard analyzed the acceleration patterns of the moving part that lead to the vibration source in linear motor. It presents the analyzed dynamic of linear motor in compliance with a change of the non-linear factor.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.23 no.2
• /
• pp.164-172
• /
• 2014

This paper presents a method for analyzing the stiffness of full and low DOF (degree of freedom) planar parallel manipulators with serially connected legs. The individual stiffness of each leg is obtained by applying reciprocal screws to the leg twist using passive joints and elastic elements consisting of actuators and links. Because the legs are connected in parallel, the manipulator stiffness is determined by summing the individual leg stiffness values. This method does not require the assumption that springs should be located along reciprocal screws and is applicable to a planar parallel manipulator with a generic or singular configuration. The stiffness values of three planar parallel manipulators with different DOFs are analyzed. The numerical results are confirmed using ADAMS S/W.