scholarly journals IMPROVING THE ACCURACY OF VIBRATION MEASUREMENT RESULTS

2021 ◽  
Vol 11 (3) ◽  
pp. 14-17
Author(s):  
Anzhelika Stakhova ◽  
Volodymyr Kvasnikov
Keyword(s):  
Measuring Transducer ◽  
Vibration Measurement ◽  
Vibration Measurements ◽  
Additional Information ◽  
Current State ◽  
Urgent Task ◽  
Measurement Results ◽  
Accuracy Of Measurement ◽  
Measuring Machine ◽  
Vibration Measuring

The current state of control of vibration measuring equipment is studied in the work, the analysis of technologies of control of vibrating measuring machine equipment is carried out. It is determined that during the control a sufficient requirement for the analysis of changes in the state over time is to conduct periodic vibration measurements in the same modes of operation of the object. Therefore, the urgent task is to increase the reliability and accuracy of measurement results. It can be enhanced by obtaining additional information. For this purpose, recommendations for optimizing the vibration control points of the mechanism are formed. To increase the accuracy of measurement results when controlling the equipment for vibration signals, the methods of mounting the measuring transducer in the equipment monitoring system are considered. It is shown that the method of mounting the measuring transducer can affect the results of vibration measurements.

Methods of Interpreting the Results of Vibration Measurements to Locate Damages in Beams

2013 ◽  
Vol 430 ◽  
pp. 84-89 ◽  
Author(s):  
Petru Florin Minda ◽  
Zeno Iosif Praisach ◽  
Andrea Amalia Minda ◽  
Gilbert Rainer Gillich
Keyword(s):  
Structural Changes ◽  
Graphic Representation ◽  
Vibration Measurement ◽  
Vibration Modes ◽  
Precise Localization ◽  
Vibration Measurements ◽  
Measurement Results ◽  
Minkowski Metrics ◽  
Selected Location

This paper deals with methods of interpreting the results of vibration measurement to identify structural changes in beam-like structures. We briefly presented an own developed damage assess method, that consider a large number of frequencies for the weak-axis banding vibration modes; it allows first a precise localization and afterwards evaluation of the damages. For the first step, recognition of the damage position, we introduce an algorithm implemented in C++ with the interface done using EXCEL features, indicating by one number the damage probable position, based on the Minkowski metrics. To avoid uncertainties, a graphic representation of all results is also presented. The method is tested for values determined by calculus for a randomly selected location, with and without measurement results debased by noise, proving its reliability.

Accuracy of Orthodontic Force and Tooth Movement Measurements

1996 ◽  
Vol 23 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Dan Lundgren ◽  
Py Owman-Moll ◽  
Jüri Kurol ◽  
Birgit Mårtensson
Keyword(s):  
Tooth Movement ◽  
Mean Value ◽  
Measurement Methods ◽  
Calibration Data ◽  
Force Measurements ◽  
Accuracy Of Measurement ◽  
Measuring Machine ◽  
Initial Force ◽  
Level Of Agreement

This study was designed to test the accuracy of measurement methods for assessment of force and tooth movement in orthodontic procedures. Daily in vivo measurements of the force produced by activated archwires showed that the initial force declined substantially (by 20 per cent of mean value) within 3 days. Both the ‘trueness’ (validity) and precision of the force measurements, obtained with a strain gauge, were found to be high (SD values were 1·0 cN and 0·4 cN, respectively). Horizontal tooth movements were measured with three different instruments: a slide calliper, a co-ordinate measuring machine, and laser measuring equipment based on holograms. There was a good level of agreement between these methods. This was also confirmed by calibration data. The precision of the methods was (SD values) 0·06, 0·07, and 0·13 mm, respectively. The benefits of the use of the co-ordinate measuring machine are obvious, since it can measure tooth movements in relation to reference planes in all directions.

METHOD FOR DETERMINING THE LIMITS OF ELASTICITY AND PROPORTIONALITY OF MATERIALS FOR SUBSEQUENT DRILLING OF WORKPIECES IN THE STRESS–STRAIN STATE

2020 ◽  
Vol 3 ◽  
pp. 164-170
Author(s):  
V.V. KUTS ◽  
A.S. BYSHKIN ◽  
M.S. RAZUMOV
Keyword(s):  
Measurement Error ◽  
Elastic Deformation ◽  
Strain State ◽  
Drilling Process ◽  
Stress Strain ◽  
Workpiece Material ◽  
Stress Strain State ◽  
Urgent Task ◽  
Accuracy Of Measurement ◽  
Proportionality Limit

Drilling holes is one of the most common operations in the manufacture of parts. As a result, improving the efficiency of this process is an urgent task. To improve the efficiency of the drilling process, a method was developed at the Southwestern University for drilling with pre–stressed–deformed material of the workpiece, in which the sample is subjected to elastic deformation at a load that does not exceed the proportionality limit of the workpiece material, that is, when the load is removed, the dimensions of the workpiece remain the same. As part of this work, an experimental device was developed and designed to determine the limits of elasticity and proportionality of materials for subsequent drilling of workpieces in a stress–strain state. This invention will improve the automation and accuracy of measurement. An example of measurement and calculation is considered. Calculation formulas for determining the measurement error are given.

Surface Texture Measurement with Profile Method Using Six-Axis Coordinate Measuring Machine

2021 ◽  
Vol 410 ◽  
pp. 872-877
Author(s):  
Andrey V. Kochetkov ◽  
Andrey A. Troshin ◽  
Oleg V. Zakharov
Keyword(s):  
Surface Texture ◽  
Measurement Errors ◽  
Coordinate Measuring Machine ◽  
Texture Measurement ◽  
Analytical Geometry ◽  
Complex Shapes ◽  
Measurement Results ◽  
Measuring Machine ◽  
Cartesian Coordinate ◽  
Filtering Effect

Currently the measurement of surface texture in mechanical engineering is traditionally carried out using profilometers. Modern profilometers do not allow measuring of surfaces with complex shapes. This is due to the different sensitivity of the sensor and the discreteness of the movements along the axes of the Cartesian coordinate system. Coordinate Measuring Machines are devoid of such a drawback. However, stylus of the coordinate measuring machine has a diameter many times larger than the diamond stylus of the profilometer. Therefore, there is a mechanical filtering effect, that affects the results of measuring the parameters of the surface texture. In this paper a mathematical model of the contact of the spherical stylus and a rough surface based on analytical geometry is proposed. Influence of the diameter of the spherical stylus on the maximum measurement errors of a amplitude parameters are investigated. Seven amplitude parameters Rp, Rv, Rz, Ra, Rq, Rsk, Rku of the surface texture are modeled. Coordinate measuring machine and profilometer with stylus diameter of 2 μm measurement results are compared. it was concluded that the stylus diameter of the coordinate measuring machine when measuring the surface texture should be no more than 20 μm.

Performance Based Evaluation of Bridge Substructure in North Mississippi Using Nonlinear FEM and Field Vibration Measurement

2000 ◽  
Author(s):  
Chris L. Mullen ◽  
Prabin R. Tuladhar
Keyword(s):  
Finite Element ◽  
Transfer Functions ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Vibration Measurement ◽  
Elastic Behavior ◽  
Evaluation Procedure ◽  
Vibration Measurements ◽  
Linear Elastic ◽  
Performance Based Evaluation

Abstract Discussion of a Performance - Based Engineering evaluation procedure for an existing interstate highway bridge in north Mississippi. The bridge is in a highly trafficked location near the Memphis Metropolitan area and is reflective of modern design practices in Mississippi. Results are presented of nonlinear damage response and displacement ductility performance of the reinforced concrete bents and their foundations predicted using static finite element (FE) computations. The model considers the composite action of the concrete and the reinforcing steel materials under axial force, shear, torsion and flexure. The performance-based evaluation includes three-dimensional computational simulations of the nonlinear bridge system, including substructures and superstructure. The response spectrum dynamic analysis method will also be carried out on the linear elastic three-dimensional model to predict the linear elastic behavior. Field vibration measurements, including ambient and hammer-impact, were performed to calibrate the models. The computed transfer functions are currently being evaluated to correlate vibration measurements and the Finite element models.

scholarly journals A Measurement Method of Microsphere with Dual Scanning Probes

2019 ◽  
Vol 9 (8) ◽  
pp. 1598 ◽  
Author(s):  
Fang ◽  
Huang ◽  
Xu ◽  
Cheng ◽  
Chen ◽  
...  
Keyword(s):  
Measurement Method ◽  
Coordinate Measuring Machine ◽  
Quartz Tuning Fork ◽  
Cross Sectional ◽  
Scanning Probes ◽  
Repeatability Error ◽  
Measurement Results ◽  
Size Standard ◽  
Measuring Machine ◽  
Tungsten Tip

The probe tip of a micro-coordinate Measuring Machine (micro-CMM) is a microsphere with a diameter of hundreds of microns, and its sphericity is generally controlled within tens to hundreds of nanometers. However, the accurate measurement of the microsphere morphology is difficult because of the small size and high precision requirement. In this study, a measurement method with two scanning probes is proposed to obtain dimensions including the diameter and sphericity of microsphere. A series of maximum cross-sectional profiles of the microsphere in different angular directions are scanned simultaneously and differently by the scanning probes. By integrating the data of these maximum profiles, the dimensions of the microsphere can be calculated. The scanning probe is fabricated by combining a quartz tuning fork and a tungsten tip, which have a fine vertical resolution at a sub-nano scale. A commercial ruby microsphere is measured with the proposed method. Experiments that involve the scanning of six section profiles are carried out to estimate the dimensions of the ruby microsphere. The repeatability error of one section profile is 15.1 nm, which indicates that the measurement system has favorable repeatability. The mainly errors in the measurement are eliminated. The measured diameter and roundness are all consistent with the size standard of the commercial microsphere. The measurement uncertainty is evaluated, and the measurement results show that the method can be used to measure the dimensions of microspheres effectively.

scholarly journals A frame for a computer aided inspection planning system

2015 ◽  
Vol 4 (1) ◽  
pp. 125 ◽  
Author(s):  
Wilma Polini ◽  
Giovanni Moroni
Keyword(s):  
Measurement Techniques ◽  
Coordinate Measuring Machine ◽  
Planning System ◽  
Inspection Planning ◽  
Coordinate Measurement ◽  
Measurement Results ◽  
Measuring Machine ◽  
Set Up ◽  
Almost All ◽  
Computer Aided Inspection

Coordinate Measuring Machine (CMM) inspection planning is an activity performed by well-trained operators, but different measurement techniques, using the same data analysis algorithms yield in different measurement results. This is a well-recognized source of uncertainty in coordinate measurement. A CMM, provided with an automatic inspection planning (CAIP) system, permits to implement more accurate and efficient operating procedures and to fit higher quality assurance standards and tighter production timings.In this paper we present a frame of a CAIP system, able to deal with almost all the decisional stages of CMM inspection. Moreover, original approaches have been developed and presented in inspection feature selection, part set-up, probe configuration, and path planning.

On the Methods for Measuring High Temperature Resistivity of Glass

2016 ◽  
Vol 680 ◽  
pp. 39-43
Author(s):  
Ying Liang Tian ◽  
Mei Zhang ◽  
Yong Ming Li ◽  
Feng Wang ◽  
Jing Ting Yang
Keyword(s):  
High Temperature ◽  
Test Procedure ◽  
Aluminosilicate Glass ◽  
Voltage Measurement ◽  
Advantages And Disadvantages ◽  
Measurement Results ◽  
Accuracy Of Measurement ◽  
High Alkali ◽  
Increasing Temperature ◽  
Temperature Resistivity

This paper described three methods for measuring high temperature resistivity of glass including their basic principles, advantages and disadvantages so as to provide a reference for measurement. The effects of electrode and voltage on high temperature resistivity were studied. Accuracy of measurement results of plate electrodes is better than wire electrodes. The resistivity of molten glass decreased with increasing AC voltage. Measurement results are stable when the voltage is less than 10 V, but when the voltage exceeds than 40 V, Joule heating effect will be generated resulting in smaller measurement values. In addition, high alkali aluminosilicate glass as object is used to introduce test procedure of temperature resistivity and explore the relationship between high temperature resistivity and alkali metal. Results show that high alkali aluminosilicate glass resistivity decreases with increasing temperature, and the effect of K2O on high tempearature resistivity is more pronounced.

Accuracy Evaluation of 5-Axis Machining Center Based on Measurements of Machined Workpiece – Evaluation of Accuracy of 5-Axis Controlled Machining Center –

2012 ◽  
Vol 6 (5) ◽  
pp. 675-681 ◽  
Author(s):  
Yoshitaka Morimoto ◽  
◽  
Keisuke Nakato ◽  
Motoshi Gontani
Keyword(s):  
Precise Measurement ◽  
Design Tool ◽  
Cutting Conditions ◽  
Accuracy Evaluation ◽  
Geometric Errors ◽  
Machining Error ◽  
Machining Center ◽  
Measurement Results ◽  
Measuring Machine ◽  
Machine Operator

A new method for evaluating the geometrical accuracy of a 5-axis Machining Center (MC) based on the measurement results of the machined workpiece has been developed. The strategy behind our method is to utilize, because of its accuracy, a Coordinates Measuring Machine (CMM) as a master gauge. Thus, the machine operator machines the workpiece and a technologist of precise measurement takes the measurements. In our study, non-rotational machining is utilized to copy and trace the machine trajectory on the workpiece, minimizing the machining error. The profiles of the machined workpiece are measured and evaluated by a CMM, and the geometric errors of the machining center are extracted. Themeasurement results are sufficiently accurate compared to those taken using the square master gauge calibrated by CMM previously. In this report, the machining setup, including workpiece design, tool design, and cutting conditions, is proposed, and the experimental procedures and results of the evaluation are given.

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