Artūras Kilikevičius

Line Scale Calibration in Non-Ideal Measurement Situation

The precision line scale calibration in dynamical mode of operation is considered. A new interferometer-controlled comparator with moving microscope has been developed and optimised in order to reduce both the measurement uncertainty and calibration process duration. Modal analysis performed and measurements conducted of the spatial vibrations of comparator structure revealed that dynamically-induced errors can noticeably contribute to the measurement uncertainty budget. They can be prominently reduced, in particular, by proper improvement and optimisation of the carriage structure and elimination of the dry friction in the carriage drive.

Identification of the Prints Elastic Parameters Using Vibrational Methods

One of the indirect tensile identification methods is the measurement of the structure of the response to the vibration excitation. Then this response is simulated using digital methods. If the similarity to the response structure is achieved, the elasticity parameters can be determined. Using the methodology discussed in this work, the problem of the determination of the elasticity parameters of prints as a consisting of the paper and several layers of inks is solved. The determined parameters of prints will be used for the modeling of the printing process in web printing presses.

Research of Influence of Vibrations on Calibration Quality of Line Scale Gauge

The essence of the considered problem is to improve line scale gauge calibration quality by studying vibrations that are induced during the calibration process. To assess the influence of vibrations it is necessary to solve a lot of scientific and technical tasks. Serious difficulties were confronted during the mathematical analysis - development of analytical model and determination of its coefficients. An in-depth analysis of line scale measurement means had to be performed to this aim, because only experimental measurements enabled to estimate the majority of coefficients.

Precision Measurement of the Carriage Vibrations at the Different Speeds

Dependence of a comparator reading dynamic error on vibro activity of a carriage is analyzed in the paper. There is shown how change reading errors at action only carriage drive vibrations and at artificially provoked carriage vibrations at different frequencies. Results achieved enable to evaluate the influence of vibration components on reading errors.

Sedimentation Influence on Magnetorheological Brake Torque Moment

The aim of our research was to determine how sedimentation in magnetorheological fluid influences torque moment of a magnetorheological brake. Five different magnetorheological fluids (MRF-140CG, MRF-122EG, from Lord Corporation, USA, MRHCCS4-A and MRHCCS4-B are from Liquids Research Company, UK and MUDZH-3, made in Luikov Heat and Mass Transfer Institute, Belarus) were tested. The viscosity of these magnetorheological fluids in the magnetic field of 0–1 T was measured on Anton Paar Physica MCR-301 rheometer. We have selected the fluid with the best parameters to fill up our made magnetorheological brake. To determine sedimentation in magneto-rheological fluid was used patent pending method by measuring fluids’ electrical resistivity. Electrical resistivity dependence on sedimentation mathematical model was created. Also four piezo-actuators were used to mix fluid inside the brake. Experimental setup to determine brakes’ torque moment was created.

An Investigation Into Fault Diagnosis in a Rotor-Bearing System with Dampers Used in Centrifugal Milk Separators

This paper deals with the problems encountered in the fault diagnosis in damped rotorbearing systems used in centrifugal milk separators. It is shown that direct bearing vibration measurements are more reliable than indirect (through rotor housing) vibration measurements. However, in most cases it is not possible to measure bearing vibrations directly. The factors causing large diagnostic measurement errors, such as the influence of the vibration damping system, step-up gear and electric motor noise are discussed in the paper. It is established that vibration measurements of the damping system are noninformative and cannot be used to diagnose faults in bearings. It is proposed to use the vibration spectra correlation to predict bearing failures in rotor-bearing systems of this type.

Dynamic Testing of Railway Truss-Bridge

The study results of the historic narrow-gage railway steel truss bridge built in the last century and still used are provided in this paper. Only one of the spans results is provided herein. Field tests with the original locomotive were carried out in order to develop an analytical model that will be used to evaluate the capacity of the bridge. Responses (dynamic displacements, accelerations, mode shapes, corresponding to the resonance frequencies and modal damping values) for the construction of the bridge were found. Studies have shown that the bridge meets the requirements and has enough reserve to work safely.

Dynamic Research on Precision Angle Measurement Comparator

The aim of the research was to determine the mechanical stability of angle measurement comparator’s system. For that purpose, vibrations were measured at the significant points of the system and dynamic characteristics of the system were established.

Effect of External Excitation on Dynamic Characteristics of Vibro-Isolating Table

Performance of optical table with pneumatic vibration isolators is analyzed within 2–50 Hz frequency range. Specific vibrational excitation platform with a vibrator of the frequency range of 1–50 Hz in one of three directions were tested.The following pneumatic vibration isolator dynamic parameters were identified:transmissibility of vertical oscillation characteristics at 50 Hz frequency range;resonant frequency (vertical direction);damping efficiency at 5 Hz to 10 Hz for excitation frequencies.

Research of Dynamics of the Precision Mechatronical Line Scale Gage Calibration System

In the paper, the research on the influence of drive fixing place on dynamic properties of the precision mechatronical line scales gage calibration comparator is analyzed. With the aim to research the influence of the drive on the mechanical system of the length measurement comparator, the drive mounting position was replaced, and the friction drive was changed for the rope drive.