• Title/Summary/Keyword: Dynamic Pressure

Search Result 2,441, Processing Time 0.028 seconds

Development of automatic measurement system for dynamic respose time of pneumatic solenoid valve (공압밸브의 동적응답 특성측정 자동화 시스템 개발)

  • 강보식;김형의
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1991.10a
    • /
    • pp.974-978
    • /
    • 1991
  • Electro-pneumatic valve is an electro-mechanical device which converts electric signal into pneumatic flow mu or pressure. A measurement of dynamic response time is very important to evaluate valve performance. Dynamic response time of electro-pneumatic valve has a variation accordance with valve types, operating way and test standard. In this study, automatic measurement system of dynamic response time is composed based on test condition of dynamic response time test standard(CETOP, JIS). Also, in this study test pressure variation characteristics accordance with variation of solenoid excitation power, and we developed dynamic response measurement system enable to compare of and analyze these two characteristics.

  • PDF

A Study on Prediction of the Liquefaction Behavior of Saturated Sandy Soils Using DSC Constitutive Equation (DSC구성방정식을 이용한 포화사질토의 액상화 거동 예측)

  • 박인준;김수일;정철민
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2000.11a
    • /
    • pp.201-208
    • /
    • 2000
  • In this study, the behavior of saturated sandy soils under dynamic loads - pore water pressure and effective stress - was investigated using Disturbed State Concept(DSC) model. The model parameters are evaluated from laboratory test data. During the process of loading and reverse loading, DSC model is utilized to trace strain-hardening and cyclic softening behavior. The procedure of back prediction proposed in this study are verified by comparing with laboratory test results. From the back prediction of pore water pressure and effective mean pressure under cyclic loading, excess pore water pressure increases up to initial effective confining pressure and effective mean pressure decrease close to zero in good greement with laboratory test results. Those results represent the liquefaction of saturated sandy soils under dynamic loads. The number of cycles at initial liquefaction using the model prediction is in good agreement with laboratory test results. Therefore, the results of this study state that the liquefaction of saturated sandy soils can be explained by the effective tress analysis.

  • PDF

Dynamic Response of Pneumatic Transmission Lines (공압 전달관의 동적 응답)

  • 박현우;박종호;신필권;심우건
    • Journal of KSNVE
    • /
    • v.9 no.2
    • /
    • pp.285-294
    • /
    • 1999
  • Transient analysis for compressible fluid flow has been performed experimentally and analytically to study the dynamic characteristics of the end volume transmission lines following a sudden pressure change a its entrance. The numerical method was developed based on the method of characteristics. The sudden pressure at its entrance was generated by rupture of diaphragm in a shock tube. The sudden pressure was used to obtain the response, as input signal for the numerical analysis. The response to the sudden pressure at the end volume was measured using a pressure transducer. The experimental result shows good agreements with the numerical result. The effects of tube length, its diameter and end volume magnitude are evaluated on the responses of the pressure and on the damping factor. It is found that the viscous damping effects on the response through the transmission pipeline becomes larger with increasing pi;eline length and decreasing diameter of the pipe and the fluid-elastic stiffness decreases with increasing the terminal volume. The numerical approach presented in this paper can be very useful in designing the instrument and control system.

  • PDF

An automatic calibration technique for piezoelectric pressure transducers (압전형 압력센서의 교정기법 자동화)

  • Hong, Sung-Soo;Choi, Ju-Ho;Yoo, Jun
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1996.10b
    • /
    • pp.1368-1371
    • /
    • 1996
  • This paper presents an automatic calibration technique for piezoelectric low pressure transducer, which is useful to measure a pressure within 500 psi. This system with automatic calibration function and error correction algorithm generates standard dynamic pressure for the calibration of sensor. With the compensation for the offset voltage and the pressure error, the accuracy and the usefulness of the proposed scheme is validated.

  • PDF

An Automatic Calibration Technique for Piezoelectric Pressure Transducers (압전형 압력센서의 교정기법 자동화)

  • 홍성수;최주호
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1996.11a
    • /
    • pp.1012-1016
    • /
    • 1996
  • This paper presents an automatic calibration technique for piezoelectic low pressure transducer, which is useful to measure a pressure within 500 psi. This system with automatic calibration function and error correction algorithm generates standard dynamic pressure for the calibration of sensor. With the compensation for the offset voltage and the pressure error, the accuracy and the usefulness of the proposed scheme is validated.

  • PDF

A Novel Direct Instantaneous Pressure Control of Hydraulic Pump System with SR Drive

  • Liang, Jianing;Kim, Tae-Hyoung;Lee, Dong-Hee;Ahn, Jin-Woo
    • Proceedings of the KIPE Conference
    • /
    • 2007.07a
    • /
    • pp.208-210
    • /
    • 2007
  • This paper proposes a novel direct instantaneous pressure control(DIPC) of hydraulic pump system with SR drive. And it has very simple control structure, because it doesn’t use any speed and torque control for adjusting pump pressure. The hysteresis band of pressure and proper switching rules can make the actual pump pressure to be constant with fast dynamic response. Therefore, the proposed DIPC method can control of hydraulic pump pressure steadily with fast dynamic response.

  • PDF

The Effect of Dynamic Characteristics of Knitted Fabrics on the Clothing Pressure of Foundation Wear (화운데이션 소재의 역학적 특성이 의복압에 미치는 영향)

  • Jung, Meung-Sun;Ryu, Duck-Hwan
    • Korean Journal of Human Ecology
    • /
    • v.11 no.1
    • /
    • pp.79-93
    • /
    • 2002
  • The purpose of this study was to determine the effect of dynamic characteristics of knitted fabrics on the clothing pressure of foundation. Five knitted fabrics of foundation were selected by different fiber types and blended ratios for the study. The dynamic characteristics of foundation wears made with five different fabrics were measured by KES-FB system method. The results of this study were as follows: 1. The tensile linearity and resilience of f1 were lower than those of other samples. While the tensile resistances of f1, f2 and f4 samples were high, the coefficients of friction of them were low. The bending rigidity and geometric roughness of f5 were higher than the others. 2. The clothing pressure of f3 all-in-one sample was the highest, and followed by f5, f4, f2 and f1, respectively. This result showed that the compression resilience affected on the clothing pressure greatly. 3. In terms of the clothing pressure by posture, the clothing pressure at $90^{\circ}$ bending posture was the highest and followed by that at standing and one-leg-up, respectively. The back part of abdomen was pressured most at $90^{\circ}$ bending posture.

  • PDF

A Comparative Study of Frequency Response Models for Pressure Transmission System (압력전달시스템을 위한 주파수응답모델들의 비교 연구)

  • Kim, Hyeonjun;Choi, Hwan-Seok
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.24 no.2
    • /
    • pp.83-93
    • /
    • 2020
  • Dynamic pressure transducer needs to be flush-mounted on hardware due to frequency response characteristics of pressure transmission system. However, it is sometimes necessary to be mounted in recessed configuration due to insufficient space for sensor installation and for protection of sensor from thermal damage. Dynamic response characteristics should be considered due to distortion of original dynamic pressure signal in the pressure transmission system. In this study, small perturbation model and 2nd order reduced model were compared with experiments and a guideline for selecting a frequency response model was suggested.

The buckling of a cross-ply laminated non-homogeneous orthotropic composite cylindrical thin shell under time dependent external pressure

  • Sofiyev, A.H.
    • Structural Engineering and Mechanics
    • /
    • v.14 no.6
    • /
    • pp.661-677
    • /
    • 2002
  • The subject of this investigation is to study the buckling of cross-ply laminated orthotropic cylindrical thin shells with variable elasticity moduli and densities in the thickness direction, under external pressure, which is a power function of time. The dynamic stability and compatibility equations are obtained first. These equations are subsequently reduced to a system of time dependent differential equations with variable coefficients by using Galerkin's method. Finally, the critical dynamic and static loads, the corresponding wave numbers, the dynamic factors, critical time and critical impulse are found analytically by applying a modified form of the Ritz type variational method. The dynamic behavior of cross-ply laminated cylindrical shells is investigated with: a) lamina that present variations in the elasticity moduli and densities, b) different numbers and ordering of layers, and c) external pressures which vary with different powers of time. It is concluded that all these factors contribute to appreciable effects on the critical parameters of the problem in question.

Dynamic Fracture Toughness of Chevron-notch Ceramic Specimens measured in Split Hopkinson Pressure Bar

  • Lee, Yeon-Soo;Yoon, Young-Ki;Yoon, Hi-Seak
    • International Journal of Precision Engineering and Manufacturing
    • /
    • v.3 no.3
    • /
    • pp.69-75
    • /
    • 2002
  • Measuring dynamic fracture toughness of brittle and small ceramic specimen is very difficult in a SHPB (Split Hopkinson Pressure Bar). As a countermeasure to this difficulty, a dynamic fracture toughness measuring method by the Chevron-notch ceramic specimen was proposed. Tested chevron specimens were of Chevron notch angles of 90$^{\circ}$, 100$^{\circ}$ and 110$^{\circ}$. Through finite element analysis, shape parameters of the Chevron-notch specimens according to notch angles were calculated. And the static fracture tough1ess of the Chevron-notch alumina specimen was measured as 3.8MPa√m similar to that of CT specimen with a precrack. Dynamic fracture toughness was 4.5MPa√m slightly higher than the static one. It was shown in this study that the proposed Chevron-notch specimens are valid to measure dynamic fracture toughness of extremely brittle materials such as ceramic.