• Title/Summary/Keyword: Static Compliance

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Studies on Audiological Significance of the Bing Test (Being test의 임상청각학적 의의에 대한 고찰)

  • 이희배;차창일;노관택
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1978.06a
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    • pp.8.3-8
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    • 1978
  • In normal auditory systems, the difference between the bone conduction thresholds obtained with the test ear opened and occluded in low frequency signals below 1, 000Hz is about 10~25 dB. But no difference in these thresholds suggests the presence of a lesion in the conductive mechanism. Sullivan added the differences in these thresholds at 250Hz, 500Hz and 1,000Hz and called "Occlusion Index". In oder to study the audiological significance, we have measured the occlusion index in 40 ears of normal persons, 20 ears of chronic otitis media patients and 20 ears of sensori-neural hearing impairment patients. We also measured the static compliance in 40 normal ears and observed the correlation with the occlusion index. The results are as follows: 1. Occlusion index was 33. $10\pm10.63dB$ in normal group, $3.10\pm3.03dB$ in chronic otitis media; group, $28.10\pm15.17dB$ in sensori-neural group. 2. Static compliance in normal group was $0.61\pm0.31cc$ (0.22~1.75cc) 3. Occlusion index showed inverse proportion to static compliance.

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Static Compliance Analysis & Multi-Objective Optimization of Machine Tool Structures Using Genetic Algorithm(I) (유전자 알고리듬을 이용한 공자기계구조물의 정강성 해석 및 다목적 함수 최적화(I))

  • 이영우;성활경
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.10a
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    • pp.443-448
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    • 2000
  • In this paper, multiphase optimization of machine structure is presented. The goal of first step is to obtain (i) light weight, (ii) rigidity statically. In this step, multiple optimization problem with two objective functions is treated using Pareto Genetic Algorithm. Where two objective functions are weight of the structure, and static compliance. The method is applied to a new machine structure design.

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An Experimental Study for the Development of Epoxy Adhesives for Optical Top (광학정반용 에폭시 접착제 개발을 위한 실험적 연구)

  • Gil, Hyeong-Gyeun;Youn, Seok-Weon;Kim, Kwang-San
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.8
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    • pp.727-733
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    • 2010
  • Optical tables provide a platform for the establishment and test of measurement systems which use Laser. Therefore, not only static characteristics such as surface flatness, static stiffness and etc. but dynamic response characteristics is very important design parameter. The dynamic stiffness is generally estimated through the modal test, and compliance is used as a representative performance standard. Recently there is an example of defining the dynamic deflection coefficient and using it as a new performance standard of the dynamic stiffness, but it is not generalized yet in industry. In this study, we verify the validity of existing DDC calculus by making an experiment on granite. And for improvement in damping performance of optical tables, we are going to evaluate the effect of fillers on the compliance, then develop an epoxy adhesive based on the result of this experiment.

Optimal Design of Vehicle Suspension System (차량 현가장치의 최적설계)

  • Tak, Tae-Oh;Chung, Sung-Hoon
    • Journal of Industrial Technology
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    • v.19
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    • pp.43-50
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    • 1999
  • Vehicle suspensions can be regarded as interconnection of rigid bodies with kinematic joints and compliance elements such as springs, bushings, and stabilizers. Design of a suspension system requires detailed specification of the interconnection point (or so called hard points) and characteristic values of compliance elements. During the design process, these design variables are determined to meet some prescribed performance targets expressed in terms of SDFs (Static Design Factors), such as toe, camber, compliance steer, etc. This paper elaborates on a systematic approach to achieve optimum design of suspension systems.

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Dynamic Fracture Testing of Welding part of Nuclear Piping by Using Normalization Method (정규화법을 이용한 원전배관 용접부의 동하중 파괴저항시험)

  • Huh, Yong;Cho, Sung-Keun;Park, Jae-Sil;Seok, Chang-Sung
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.262-267
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    • 2004
  • The unloading compliance method is the most commonly used method to evaluate the fracture resistance characteristics of a material. In dynamic loading condition, the direct current potential drop(DCPD) method has been used because the unloading compliance method can not be applied due to the discontinuity of loading. However, even in the dynamic test using DCPD method, there is a problem that the voltage drops sharply on the initiation of crack. For the reason metioned above, the normalization method was suggested on ASTM E 1820 which is revised recently, as a new method to evaluate the dynamic fracture resistance characteristic. The nomalization method can be used to obtain a fracture resistance curve directly from a load-load line displacement. In this study, we obtained two fracture resistance curves from static test of welding part of nuclear piping both by unloading compliance and nomalization method. The two curves were almost same each other, so the adaptability of the nomalization method has been proved. We conducted a dynamic fracture resistance test for the same material. The fracture resistance curve from the dynamic test was obtained by normalization method and compared to that of the static test result.

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The Effects of Chest Physiotherapy on Sputum Amount, Lung Compliance, Tidal Volume and Oxygen Saturation of Intensive Care Unit Patients Mechanical Ventilated (흉부물리요법이 인공호흡기환자의 객담량, 폐유순도, 일회호흡량 및 산소포화도에 미치는 효과)

  • Seo, Kyoung-San;Kwon, En-Ok
    • Journal of Korean Critical Care Nursing
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    • v.2 no.1
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    • pp.15-25
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    • 2009
  • Purpose: This study investigated the effects of chest physiotherapies on intensive care unit patients mechanical ventilated. Methods: Good lung down position, chest percussion, postural drainage was applied to patients who admitted to ICU. Each patients divided into four groups and each group received different treatments. Sputum amount, lung compliance, tidal volume and oxygen saturation were measured before treatment and immediately, and time flowing. Data was analyzed with frequency, percentage, ANOVA and paired t-test using via SPSSWIN 12.0 program. Results: There were significant differences in variables each characteristics of subjects. Chest percussion increased tidal volume, static lung compliance for the mean time. Desaturation related to suction. Conclusion: Chest percussion influences on lung compliance. Based on this study results and limitation, this study suggests repeated studies in various groups

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Analysis on the Bonded Single Lap-Joint Containing the Interface Edge Crack (에지계면균열을 갖는 단순겹치기 접착이음의 강도평가)

  • Yoo, Young-Chul;Park, Jung-Hwan;Lee, Won
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.6
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    • pp.159-166
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    • 1998
  • The problem of interface crack in the bonded structures has received a great deal of attention in recent years. In this paper the aluminum bonded single lap-joint containing the interface edge crack is investigated. The tensile load and the average shear stress of the adhesive joints which have different crack length are obtained from the static tensile tests. The critical value of crack length to provoke the interface fracture is determined to a/L=0.4, where a is the interface crack length and L is the adhesive lap-length. The fracture mechanical parameters are introduced to confirm the existence of the critical crack length. The compliance and the stress intensity factors are calculated using the displacement and the stress near the interface crack tip by the boundary element method. These numerical results support the experimental results that the critical value of a/L is 0.4. It is known that the compliance and the stress intensity factors are the efficient parameters to estimate the bonded single lap-joint containing the interface edge crack.

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Optimum Positioning of Rests Considering Compliance of Grinding Machine, Workpiece and Rests in Cylindrical Traverse Grinding (가로원통연삭시 연삭기와 공작물 및 방진구의 컴플라이언스를 고려한 방진구의 최적위치 선정)

  • 서장렬;이선규
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.4
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    • pp.173-180
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    • 2000
  • In the process of grinding a long slender type workpiece, such as ballscrew, by the external cylindrical grinding machine, the cylindricity of the workpiece depends on the distance of rests, the stiffness of supports, the diameter and material of workpiece. Conventionally the process needs to be supported by one or more rests to prevent static deflection and vibration. In this paper, the optimal position of the rests was investigated in order to minimize the cylindricity due to the static deflection, by taking compliance of the workpiece and structure into account. In order to obtain the optimal position of rests, a new modeling that is considering the spring effect of all support elements was established. Since it is so complicated to obtain the optimal position analytically for various conditions due to discontinuity, a genetic algorithm u as utilized.

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Static Compliance Analysis & Multi-Objective Optimization of Machine Tool Structures Using Genetic Algorithm(II) (유전자 알고리듬을 이용한 공작기계구조물의 정강성 해석 및 다목적 함수 최적화(II))

  • 이영우;성활경
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.10a
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    • pp.231-236
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    • 2001
  • The goal of multiphase optimization of machine structure is to obtain 1) light weight, 2) statically and dynamically rigid structure. The entire optimization process is carried out in two phases. In the first phase, multiple optimization problem with two objective functions is treated using pareto genetic algorithm. Two objective functions are weight of the structure, and static compliance. In the second phase, maximum receptance is minimized using genetic algorithm. The method is applied to design of quill type machine structure with back column.

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Performance Analysis of Air Foil Bearings with Bump Friction (범프 마찰을 고려한 공기포일베어링의 성능해석)

  • Kim, Young-Cheol;Lee, Dong-Hyun;Kim, Kyung-Cheol
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.803-809
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    • 2005
  • This paper presents the theoretical model to investigate the effect of Coulomb damping in the sub-structure of a foil bearing. Foil deflection is restricted by friction of bumps. Equivalent viscous damping of the bump foils is derived from the Coulomb friction. Dynamic equation of the bumps is constituted by stiffness and damping terms. This point give the difference from Heshmat's frictionless and simple compliance bump model. The fluid is modeled with the compressible Reynolds equation. A perturbation approach is used to determine the static and dynamic performance of the bearing from the coupled fluid-structural model. The analysis result shows that the static and dynamic performance is enhanced by bump friction. This analysis technique would be extended to development of a high performance bearing.

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