Steady-State and dynamic properties of concentrated fiber-filled thermoplastics

1995 ◽  
Vol 35 (21) ◽  
pp. 1670-1681 ◽  
Author(s):  
Joseph P. Greene ◽  
James O. Wilkes
Keyword(s):  
Steady State ◽  
Dynamic Properties

Steady-State and Dynamic Properties of the Floating-Ring Journal Bearing

1968 ◽  
Vol 90 (1) ◽  
pp. 243-253 ◽  
Author(s):  
F. K. Orcutt ◽  
C. W. Ng
Keyword(s):  
Steady State ◽  
Journal Bearing ◽  
Dynamic Properties ◽  
Calculated Data ◽  
Experimental Results ◽  
Supply Pressure ◽  
Pressure Parameter

Calculated data on steady-state and dynamic properties of the plain cylindrical floating-ring bearing with pressurized lubricant supply are given. The data are for a bearing with L/D of 1, and values of the ratio of inner to outer film clearances of 0.7 and 1.3. One value of dimensionless supply pressure parameter is covered. Experimental results are presented which verify the calculated results and which supplement them, particularly with respect to stability characteristics of the bearing.

Dynamic characterization and hemodynamic effects of pulmonary waves in fetal lambs using cardiac extrasystoles and beat-by-beat wave intensity analysis

2009 ◽  
Vol 297 (2) ◽  
pp. R428-R436 ◽  
Author(s):  
Joseph J. Smolich ◽  
Jonathan P. Mynard ◽  
Daniel J. Penny
Keyword(s):  
Steady State ◽  
Compression Wave ◽  
Dynamic Properties ◽  
Wave Intensity ◽  
Late Gestation ◽  
Ventricular Contractility ◽  
Pulmonary Hemodynamics ◽  
Fetal Sheep ◽  
Pulmonary Vasoconstriction ◽  
Time Flow

Steady-state wave intensity ( WI) analysis indicates that characteristic midsystolic falls in fetal pulmonary trunk (PT) and artery (PA) blood flow are due to an extremely large backward-running compression wave (BCWms) that 1) originates from the pulmonary microvasculature by a combination of cyclical pulmonary vasoconstriction and vascular reflection of the forward-running compression wave (FCWis) associated with impulsive right ventricular ejection, and 2) is transmitted into the PT. However, no information is available about the dynamic properties of PA BCWms and its contribution to beat-to-beat regulation of pulmonary hemodynamics. Accordingly, beat-by-beat WI analysis was performed during brief increases in ventricular contractility accompanying an extrasystole (ES) in nine anesthetized late-gestation fetal sheep instrumented with PT and left PA micromanometer catheters to measure pressure (P) and transit-time flow probes to obtain blood velocity ( U). WI was calculated as the product of P and U rates of change. At steady state, the magnitude of PA BCWms, and its associated P and U changes (ΔP and Δ U, respectively), were similar to those of FCWis. The PA FCWis and BCWms, and their accompanying ΔP and Δ U, were all transiently potentiated after an ES. Beat-by-beat PA FCWis-BCWms wave area, ΔP and Δ U relationships were highly linear ( R2 ≥ 0.91) with slopes of 1.36–1.47 ( P < 0.001), consistent with the presence of a vasoconstrictor component in PA BCWms. PA-PT BCWms area and ΔP and Δ U relationships were also linear ( R2 ≥ 0.77) with slopes of 0.23–0.64 ( P < 0.001). These results indicate that the fetal PA BCWms contributes to beat-to-beat regulation of not only PA but also PT hemodynamics.

scholarly journals Dynamic properties of piecewise linear systems with fractional time-delay feedback

2021 ◽  
pp. 146134842110076
Author(s):  
Jianchao Zhang ◽  
Jun Wang ◽  
Jiangchuan Niu ◽  
Yufei Hu
Keyword(s):  
Steady State ◽  
Time Delay ◽  
Analytical Solution ◽  
Goodness Of Fit ◽  
Numerical Solutions ◽  
Dynamic Properties ◽  
Piecewise Linear ◽  
Steady State Solution ◽  
State Solution ◽  
Comparison Results

The forced vibration of a single-degree-of-freedom piecewise linear system containing fractional time-delay feedback was investigated. The approximate analytical solution of the system was obtained by employing an averaging method. A frequency response equation containing time delay was obtained by studying a steady-state solution. The stability conditions of the steady-state solution, the amplitude–frequency results, and the numerical solutions of the system under different time-delay parameters were compared. Comparison results indicated a favorable goodness of fit between the two parameters and revealed the correctness of the analytical solution. The effects of the time-delay and fractional parameters, piecewise stiffness, and piecewise gap on the principal resonance and bifurcation of the system were emphasized. Results showed that fractional time delay occurring in the form of equivalent linear dampness and stiffness under periodic variations in the system and influenced the vibration characteristic of the system. Moreover, piecewise stiffness and gap induced the nonlinear characteristic of the system under certain parameters.

Experimental Evaluation of Foil Bearing Performance: Steady-State and Dynamic Results

2009 ◽  
Author(s):  
M. J. Conlon ◽  
A. Dadouche ◽  
W. M. Dmochowski ◽  
R. Payette ◽  
J.-P. Be´dard ◽  
...  
Keyword(s):  
Steady State ◽  
High Speed ◽  
First Generation ◽  
Dynamic Properties ◽  
Operating Conditions ◽  
Pneumatic Cylinder ◽  
Test Procedures ◽  
Foil Bearings ◽  
Foil Bearing ◽  
Stepped Shaft

An experimental facility dedicated to measuring both the steady-state and dynamic properties of foil bearings, under a variety of operating conditions, has been designed and commissioned. The bearing under test is placed at the midspan of a horizontal, simply-supported, stepped shaft which rotates at up to 60 krpm. Static and dynamic loads of up to 3500 N and 450 N (respectively) can be applied by means of a pneumatic cylinder and two electrodynamic shakers. This paper outlines the test procedures and data analysis methods pertaining to the operation of the high-speed, oil-free bearing test rig, and presents steady-state and dynamic results for a first-generation foil bearing. The test bearing, which was fabricated in-house, is 0.07 m diameter and has an aspect ratio of 1; bearing manufacturing details are provided.

1H NMR spectroscopy study of the dynamic properties of glycogen in solution by steady-state magnetisation measurement with off-resonance irradiation

1998 ◽  
Vol 306 (4) ◽  
pp. 479-491 ◽  
Author(s):  
Claire Wary ◽  
Hervé Desvaux ◽  
Marc Van Cauteren ◽  
Florent Vanstapel ◽  
Pierre G Carlier ◽  
...  
Keyword(s):  
Steady State ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Dynamic Properties ◽  
Spectroscopy Study ◽  
Magnetisation Measurement

scholarly journals Experimental and theoretical investigations on sensing and dynamic characteristics of PVDF thin film

2020 ◽  
Vol 37 ◽  
pp. 1-12
Author(s):  
Yu-Chih Lin ◽  
Yu-Hsi Huang ◽  
Chien-Ching Ma ◽  
Chun-Kai Chang
Keyword(s):  
Steady State ◽  
Dynamic Characteristics ◽  
Polyvinylidene Fluoride ◽  
Dynamic Properties ◽  
Speckle Pattern ◽  
Laser Doppler Vibrometer ◽  
Piezoelectric Element ◽  
Electronic Speckle Pattern Interferometry ◽  
Element Analysis ◽  
Transient Dynamic

Abstract This research investigates both the steady-state and transient dynamic characteristics of polyvinylidene fluoride (PVDF), which is one of the most commonly used piezoelectric polymers. In steady-state vibration, the visible resonant mode fringe patterns are obtained using the amplitude-fluctuation electronic speckle pattern interferometry experiment, and the point-wise displacement data are measured by laser Doppler vibrometer–dynamic signal analysis. Finite element analysis is also performed, and the numerical results are compared with the experimental ones for the steady-state vibration. In a transient dynamic experiment, the history of dynamic impact generated by a steel ball is measured by the PVDF, and the experimental results are compared with the theoretical results obtained by the Hertz contact law. The comprehensive information about steady-state and transient dynamic properties of PVDF membranes obtained in this study is expected to contribute to the further development of the PVDF piezoelectric element.

scholarly journals Non-Linear Model Dynamics Analysis for Aerospace Engineering Structures Subjected to Non-Steady-State Random Loads

2020 ◽  
pp. 42-55
Author(s):  
O.N. Tushev ◽  
A.V. Belyaev ◽  
Yizhou Wang
Keyword(s):  
Steady State ◽  
Dynamic Properties ◽  
High Reliability ◽  
Aerospace Engineering ◽  
Design Stage ◽  
Engineering Structures ◽  
Non Linear ◽  
Coordinate Vector ◽  
External Forces ◽  
Non Linear System

In aerospace engineering, it is customary to employ stochastic analysis methods at the design stage to investigate how the mechanical system responds to random external forces. This is relevant due to high reliability requirements for spacecraft. We developed a method for probabilistic estimation of the dynamic properties of a structure subjected simultaneously to external (additive) and parametric (multiplicative) vibrations. An ordinary non-linear vector differential equation describes the vibrations in the elastic structure. Non-linear position and velocity properties of kinematic pairs may have cusps and discontinuities. We assume that the probabilistic dispersions of respective phase coordinates are close to the normal distribution of probability density. The initial non-linear vibration equations are statistically linearised. The system of differential equations is not rewritten in the canonical form, which means that it is possible to carry out the probabilistic analysis of the system for any external non-steady-state effect. The fundamental matrix of the linearised system is used to find the expected value vector and the correlation function matrix of the phase coordinate vector. The solution consists of a matrix integro-power series containing linear and quadratic terms. Using the method makes it possible to assess the contribution of each external force component to the total result. We consider an example of a non-linear system responding to a stepwise non-steady-state external influence.

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