Modelling of a Dynamic Torque Calibration Device and Determination of Model Parameters

For the dynamic calibration of torque transducers, a calibration device has been developed. This paper describes the model of the measuring device and methods for the determination of its model parameters. The modelling of the calibration set-up is required for the identification of the corresponding model parameters of the torque transducer under test. These parameters describe the transducer's dynamic behaviour. Measurement methods and devices for the determination of mass moment of inertia and torsional stiffness are explained. This research is part of EMRP JRP IND09 - "Traceable Dynamic Measurement of Mechanical Quantities".

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Dynamic torque calibration by means of model parameter identification

ACTA IMEKO ◽

10.21014/acta_imeko.v4i2.211 ◽

2015 ◽

Vol 4 (2) ◽

pp. 39 ◽

Cited By ~ 3

Author(s):

Leonard Klaus ◽

Barbora Arendacká ◽

Michael Kobusch ◽

Thomas Bruns

Keyword(s):

Frequency Response ◽

Dynamic Behaviour ◽

Measurement Data ◽

Model Parameters ◽

Dynamic Calibration ◽

Extended Model ◽

Unknown Parameters ◽

Measuring Device ◽

Torque Transducer ◽

Least Squares Approach

For the dynamic calibration of torque transducers, a model of the transducer and an extended model of the mounted transducer including the measuring device have been developed. The dynamic behaviour of a torque transducer under test is going to be described by its model parameters. This paper describes the models with these known and unknown parameters and how the calibration measurements are going to be carried out. The principle for the identification of the transducer's model parameters from measurement data is described using a least squares approach. The influence of a variation of the transducer's parameters on the frequency response of the expanded model is analysed.

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Determination of mechanical properties of soil under laboratory conditions

Research in Agricultural Engineering ◽

10.17221/37/2013-rae ◽

2014 ◽

Vol 60 (Special Issue) ◽

pp. S66-S69 ◽

Cited By ~ 1

Author(s):

V. Malý ◽

M. Kučera

Keyword(s):

Mechanical Properties ◽

Penetration Depth ◽

Measuring Device ◽

Laboratory Conditions ◽

Measuring Network ◽

Set Up ◽

Different Diameters ◽

Different Levels ◽

Properties Of Soil

This paper presents the mechanical properties of soil. In order to determine the properties of soil under laboratory conditions, a special measuring device was constructed, viz. a bevameter. Two types of soil with different levels of moisture were examined and their mechanical properties were determined. Measurements were taken of non-compressed soil. A measuring network was set up, consisting of measuring and recording devices. In the course of measuring, the force and penetration depth of the pressing plate were recorded simultaneously. Three different diameters of pressing plate were used, namely 38, 50 and 70 mm. The pressure on the contact area was calculated after completion of the measurements, and the relationships between pressure and penetration depth were presented graphically.

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Experimental Determination of the Mass Moment of Inertia of a Flywheel Using Dynamics and Statistical Methods

Volume 4A: Dynamics, Vibration, and Control ◽

10.1115/imece2015-53557 ◽

2015 ◽

Author(s):

Pezhman Hassanpour ◽

Monica Weaser ◽

Ray Colquhoun ◽

Khaled Alghemlas ◽

Abdullah Alrashdan

Keyword(s):

Experimental Determination ◽

Accurate Result ◽

Moment Of Inertia ◽

The Other ◽

Experimental Measurements ◽

Ball Bearings ◽

Experiment Data ◽

Mass Moment ◽

Mass Moment Of Inertia

This paper presents the analysis of the mass moment of inertia (MMI) of a flywheel using experiment data. This analysis includes developing two models for determining the MMI of the flywheel. The first model considers the effect of mass moment of inertia only, while the second model takes the effect of friction in the ball bearings into consideration. The experiment results have been used along with both models to estimate the MMI of the flywheel. It has been demonstrated that while the model with no friction can be used for estimating the MMI to some extent, the model with friction produces the most accurate result. On the other hand, an effective application of the model with friction requires several experimental measurements using different standard masses. This translates into more expensive method in terms of experiment time and equipment cost.

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An approach to identify time consistent model parameters: sub-period calibration

Hydrology and Earth System Sciences ◽

10.5194/hess-17-149-2013 ◽

2013 ◽

Vol 17 (1) ◽

pp. 149-161 ◽

Cited By ~ 64

Author(s):

S. Gharari ◽

M. Hrachowitz ◽

F. Fenicia ◽

H. H. G. Savenije

Keyword(s):

Model Performance ◽

Realistic Model ◽

Parameter Estimates ◽

Model Parameters ◽

New Approach ◽

Consistent Model ◽

Set Up ◽

Consistent Parameter

Abstract. Conceptual hydrological models rely on calibration for the identification of their parameters. As these models are typically designed to reflect real catchment processes, a key objective of an appropriate calibration strategy is the determination of parameter sets that reflect a "realistic" model behavior. Previous studies have shown that parameter estimates for different calibration periods can be significantly different. This questions model transposability in time, which is one of the key conditions for the set-up of a "realistic" model. This paper presents a new approach that selects parameter sets that provide a consistent model performance in time. The approach consists of testing model performance in different periods, and selecting parameter sets that are as close as possible to the optimum of each individual sub-period. While aiding model calibration, the approach is also useful as a diagnostic tool, illustrating tradeoffs in the identification of time-consistent parameter sets. The approach is applied to a case study in Luxembourg using the HyMod hydrological model as an example.

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Dynamical behaviour of a torsional system with parametric and external excitations

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/0954406001523182 ◽

2000 ◽

Vol 214 (7) ◽

pp. 955-973

Author(s):

G Adiletta ◽

A R Guido

Keyword(s):

Degrees Of Freedom ◽

Dynamic Behaviour ◽

Asynchronous Motor ◽

Dynamical Behaviour ◽

Lumped Parameter ◽

Mass Moment ◽

Mass Moment Of Inertia ◽

Torsional System ◽

Parametric And External Excitations ◽

Crank Mechanism

The dynamic behaviour of a torsional system with a one-cylinder, reciprocating compressor driven by an asynchronous motor is studied using a two degrees-of-freedom (2 DOF) lumped-parameter theoretical model. The model takes into account the variability of the mass moment of inertia of the crank mechanism and the presence of pressure forces loading the compressor piston. The influence of the ratio of the variable to the constant part of inertia in the crank mechanism and the effect of the load torque due to pressure forces acting on the piston are examined in relation to system dynamic behaviour. Experimental data, obtained with the adoption of a suitable rig, show that the theoretical indications can be considered reliable, despite the approximation that was given to the mathematical model as far as the treatment of the damping and the absence of clearances were concerned.

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Natural Frequencies of Nonuniform Beams on Multiple Elastic Supports

Journal of Applied Mechanics ◽

10.1115/1.4011688 ◽

1958 ◽

Vol 25 (1) ◽

pp. 57-63

Author(s):

R. A. Di Taranto

Keyword(s):

Natural Frequencies ◽

Forced Vibrations ◽

Moment Of Inertia ◽

Elastic Supports ◽

Mass Moment ◽

End Conditions ◽

Mass Moment Of Inertia ◽

Gyroscopic Effects

Abstract A method is presented for the determination of the natural frequencies of nonuniform beams on two or more torsionally and linearly elastic supports, including the effect of rotary mass moment of inertia. The method employed is an extension of the Myklestad method. The cases of two supports with varied end conditions and three supports with a torsional and linear restraint at each support are formulated. It is indicated how this method may be used for problems concerning forced vibrations of beams on multiple elastic supports and for the determination of critical rotor speeds including gyroscopic effects.

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Comparison of Two Experiments Based on a Physical and a Torsion Pendulum to Determine the Mass Moment of Inertia Including Measurement Uncertainties

Measurement Science Review ◽

10.1515/msr-2017-0002 ◽

2017 ◽

Vol 17 (1) ◽

pp. 9-18 ◽

Cited By ~ 6

Author(s):

Leonard Klaus

Keyword(s):

Small Mass ◽

Moment Of Inertia ◽

Torsion Pendulum ◽

Physical Pendulum ◽

Uncertainty In Measurement ◽

Analysis Measurement ◽

Mass Moment ◽

Mass Moment Of Inertia ◽

Measurement Uncertainties ◽

Set Up

Abstract To determine the mass-moment-of-inertia properties of devices under test with particularly small mass moments of inertia (some 10−4 kg m2), two measurement set-ups based on different measurement principles were developed. One set-up is based on a physical pendulum, the second set-up incorporates a torsion pendulum. Both measurement set-ups and their measurement principles are described in detail, including the chosen data acquisition and analysis. Measurement uncertainty estimations according to the Guide to the Expression of Uncertainty in Measurement (GUM) were carried out for both set-ups by applying Monte Carlo simulations. Both set-ups were compared using the same three devices under test. For each measurement result, the measurement uncertainties were estimated. The measurement results are compared in terms of consistency and the resulting measurement uncertainties. For the given devices under test, the torsion pendulum set-up gave results with smaller measurement uncertainties compared to the set-up incorporating a physical pendulum.

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Development of a pulse reconstruction routine for Transistor-Reset Preamplifiers for (n,xn) measurements using HPGe detectors at the n_TOF facility at CERN

HNPS Proceedings ◽

10.12681/hnps.1824 ◽

2019 ◽

Vol 26 ◽

pp. 224

Author(s):

A. Stamatopoulos ◽

M. Kokkoris ◽

R. Vlastou ◽

N. Patronis ◽

L. Tassan-Got ◽

...

Keyword(s):

Cross Sections ◽

Pulse Shape ◽

Feasibility Studies ◽

Nuclear Model ◽

Model Parameters ◽

Analysis Framework ◽

Γ Radiation ◽

Hpge Detectors ◽

Set Up

The knowledge of neutron induced cross-sections is essential both for applications as well as for the refinement of nuclear model parameters. Amongst other reactions, (n,xn) are equally important, however the determination of such cross-sections could be limited by current experimental techniques. In this respect, feasibility studies have been performed at the n_TOF facility at CERN concerning the study of (n,xn) reactions by detecting the prompt γ radiation emitted from the residual nuclei an experimental technique which required the use of a Transistor Reset Preamplifier (TRP) set-up. The digital acquisition system at n_TOF is accompanied by a pulse shape analysis framework which lacked the capability of dealing with TRP, therefore a new reconstruction routine had to be developed. A brief description and the first preliminary results are presented.

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