VIBRATORY ACTIVITY INVESTIGATION OF GRINDING MACHINE ELECTRIC SPINDLES

2021 ◽  
Vol 2021 (6) ◽  
pp. 23-29
Author(s):  
Erik Gasparov ◽  
Lana Gasparova ◽  
Gevorg Markosyan
Keyword(s):  
Spectrum Analysis ◽  
Dynamic Properties ◽  
Harmonic Oscillation ◽  
Rotation Frequency ◽  
Linear Increase ◽  
Acceleration Signal ◽  
Spindle Unit ◽  
Spindle Rotation ◽  
Vibratory Acceleration ◽  
The Impact

The purpose of this work is to support dynamic properties of spindle units in grinding machines. For this there are problems under solution for the definition of the origin of the constituents in the spindle unit vibratory activity by means of the linear increase of electric spindle rotation frequency, obtaining and analyzing a vibratory acceleration signal for the possibility to determine a preload. The vibratory acceleration signal was investigated through a spectrum analysis method. A scientific novelty of investigation consists in the substantiation of possibility to determine a preload by means of the spectrum analysis of a vibration acceleration signal at the linear increase of spindle rotation frequency that is at starting. It gives, in its turn, a possibility for the automated estimate of the spindle unit state before cutting beginning. In the experimental way there are obtained temporal realizations of the vibratory acceleration signal at different efforts of the preload. A high-speed grinding motor-spindle is as a basic element of the bench, which was investigated through the methods of testing diagnostics in the operation. In the bench design there were made some alterations. The bench was supplemented with the systems essential to support motor-spindle full operation, in particular: with systems of lubrication, cooling and drive control. There was revealed a large number of harmonics multiple to 50 Hz, which tells of the connection with the frequency of power supply circuit. Their coincidence with the own frequencies of the spindle unit results in the considerable increase of their amplitudes. To increase dynamic quality one should avoid the cases of the coincidence of switching frequencies and circuit harmonics with own frequencies of the electric spindle. It is also necessary to bring a form of power voltage to a pure harmonic oscillation to decrease the impact of a drive electromagnetic field upon dynamic characteristics of the spindle unit.

The impact of humic and fulvic acids on the dynamic properties of liposome membranes: the ESR method

2013 ◽  
Vol 24 (2) ◽  
pp. 106-112 ◽  
Author(s):  
Dariusz Man ◽  
Izabella Pisarek ◽  
Michał Braczkowski ◽  
Barbara Pytel ◽  
Ryszard Olchawa
Keyword(s):  
Dynamic Properties ◽  
Fulvic Acids ◽  
Humic And Fulvic Acids ◽  
The Impact

scholarly journals Simulation Verification of the Contact Parameter Influence on the Forces’ Course of Cereal Grain Impact against a Stiff Surface

2021 ◽  
Vol 11 (2) ◽  
pp. 466
Author(s):  
Włodzimierz Kęska ◽  
Jacek Marcinkiewicz ◽  
Łukasz Gierz ◽  
Żaneta Staszak ◽  
Jarosław Selech ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Decisive Role ◽  
Force Sensor ◽  
Contact Forces ◽  
Correct Selection ◽  
Contact Parameter ◽  
Cereal Grain ◽  
Wide Range ◽  
The Impact ◽  
Selection Of

The continuous development of computer technology has made it applicable in many scientific fields, including research into a wide range of processes in agricultural machines. It allows the simulation of very complex physical phenomena, including grain motion. A recently discovered discrete element method (DEM) is used for this purpose. It involves direct integration of equations of grain system motion under the action of various forces, the most important of which are contact forces. The method’s accuracy depends mainly on precisely developed mathematical models of contacts. The creation of such models requires empirical validation, an experiment that investigates the course of contact forces at the moment of the impact of the grains. To achieve this, specialised test stations equipped with force and speed sensors were developed. The correct selection of testing equipment and interpretation of results play a decisive role in this type of research. This paper focuses on the evaluation of the force sensor dynamic properties’ influence on the measurement accuracy of the course of the plant grain impact forces against a stiff surface. The issue was examined using the computer simulation method. A proprietary computer software with the main calculation module and data input procedures, which presents results in a graphic form, was used for calculations. From the simulation, graphs of the contact force and force signal from the sensor were obtained. This helped to clearly indicate the essence of the correct selection of parameters used in the tests of sensors, which should be characterised by high resonance frequency.

Characterization of Adaptive Magnetoelastic Metamaterials Under Applied Magnetic Fields

2016 ◽  
Author(s):  
Ryan L. Harne ◽  
Zhangxian Deng ◽  
Marcelo J. Dapino
Keyword(s):  
Magnetic Particle ◽  
Performance Metrics ◽  
Noise Control ◽  
Dynamic Properties ◽  
Dynamic Stiffness ◽  
Structural Vibration ◽  
Dynamic Force ◽  
Particle Alignment ◽  
The Impact

Whether serving as mounts, isolators, or dampers, elastomer-based supports are common solutions to inhibit the transmission of waves and vibrations through engineered systems and therefore help to alleviate concerns of radiated noise from structural surfaces. The static and dynamic properties of elastomers govern the operational conditions over which the elastomers and host structures provide effective performance. Passive-adaptive tuning of properties can therefore broaden the useful working range of the material, making the system more robust to varying excitations and loads. While elastomer-based metamaterials are shown to adapt properties by many orders of magnitude according to the collapse of internal void architectures, researchers have not elucidated means to control these instability mechanisms such that they may be leveraged for on-demand tuning of static and dynamic properties. In addition, while magnetorheological elastomers (MREs) exhibit valuable performance-tuning control due to their intrinsic magnetic-elastic coupling, particularly with anisotropic magnetic particle alignment, the extent of their properties adaptation is not substantial when compared to metamaterials. Past studies have not identified means to apply anisotropic MREs in engineered metamaterials to activate the collapse mechanisms for tuning purposes. To address this limited understanding and effect significant performance adaptation in elastomer supports for structural vibration and noise control applications, this research explores a new concept for magnetoelastic metamaterials (MM) that leverage strategic magnetic particle alignment for unprecedented tunability of performance and functionality using non-contact actuation. MM specimens are fabricated using interrelated internal void topologies, with and without anisotropic MRE materials. Experimental characterization of stiffness, hysteretic loss, and dynamic force transmissibility assess the impact of the design variables upon performance metrics. For example, it is discovered that the mechanical properties may undergo significant adaptation, including two orders of magnitude change in mechanical power transmitted through an MM, according to the introduction of a 3 T free space external magnetic field. In addition, the variable collapse of the internal architectures is seen to tune static stiffness from finite to nearly vanishing values, while the dynamic stiffness shows as much as 50% change due to the collapsing architecture topology. Thus, strategically harnessing the internal architecture alongside magnetoelastic coupling is found to introduce a versatile means to tune the properties of the MM to achieve desired system performance across a broad range of working conditions. These results verify the research hypothesis and indicate that, when effectively leveraged, magnetoelastic metamaterials introduce remarkably versatile performance for engineering applications of vibration and noise control.

Forming Canonical 8D Data Clouds to Explore the Transient Dynamics of Physical Stiffened Plates: A Machine Learning Approach for Complex Mechanical Structures

2020 ◽  
Author(s):  
Ioannis T. Georgiou
Keyword(s):  
Machine Learning ◽  
Large Scale ◽  
Complex Structure ◽  
Spatial Dimension ◽  
Physical Structure ◽  
Transient Dynamics ◽  
Alloy Plate ◽  
Considerable Uncertainty ◽  
Acceleration Signal ◽  
The Impact

Abstract This work presents a data-driven explorative study of the physics of the dynamics of a physical structure of complicated geometry. The geometric complexity of the physical system renders the typical single sensor acceleration signal quite complicated for a physics interpretation. We need the spatial dimension to resolve the single sensory signal over its entire time horizon. Thus we are introducing the spatial dimension by the canonical eight-dimensional data cloud (Canonical 8D-Data Cloud) concept to build methods to explore the impact-induced free dynamics of physical complex mechanical structures. The complex structure in this study is a large scale aluminum alloy plate stiffened by a frame made of T-section beams. The Canonical 8D-Data Cloud is identified with the simultaneous acceleration measurements by eight piezoelectric sensors equally spaced and attached on the periphery of a circular material curve drawn on the uniform surface of the stiffened plate. The Data Cloud approach leads to a systematic exploration-discovery-quantification of uncertainty in this physical complex structure. It is found that considerable uncertainty is stemming from the sensitivity of transient dynamics on the parameters of space-time localized force pulses, the latter being used as a means to diagnose the presence of structural anomalies. The Data Cloud approach leads to aspects of machine learning such as reduced dynamics analytics of big sensory data by means of heavenly machine-assisted computations to carry out the unparalleled data reduction analysis enabled by the Advanced Proper Orthogonal Decomposition Transform. Emphasized is the connection between the characteristic geometric features of high-dimensional datasets as a whole, the Data Cloud, and the modal physics of the dynamics.

scholarly journals Polymer concrete and fibre concrete as efficient materials for manufacture of gear cases and pumps

2020 ◽  
Vol 168 ◽  
pp. 00018
Author(s):  
Kassym Yelemessov ◽  
Leonid Krupnik ◽  
Sayin Bortebayev ◽  
Bauyirzhan Beisenov ◽  
Dinara Baskanbayeva ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Steel Fibre ◽  
Rotation Frequency ◽  
Metallurgical Industry ◽  
Engineering Industry ◽  
Polymer Concrete ◽  
Test Bed ◽  
Casting Method ◽  
Fibre Concrete ◽  
The Impact

The paper describes the results of investigations on application of composite materials – polymer concrete and fibre concrete for manufacture gear cases of mechanisms used in mining and metallurgical industry centrifugal pump casings. The methods of establishing efficient compositions of polymer concrete and fibre concrete, based on a filler with gapped grading in which the pinholes in coarse fractions are filled with smaller fractions have been developed. After hardening, such mixtures have the strength 1.5...2 times higher than the items made of metal. The efficient additive of steel fibre to fibre concrete has been identified which improves the strength characteristics. The regularities of the impact on the strength and structure of polymer concrete and fibre concrete of the rotation frequency of the working element of the mixer and time of mixing the mixture components are identified. TS-250 gear and centrifugal pump casings are made by casting method and are tested on a test bed. The results obtained make it possible for us to recommend the developed compositions of polymer concrete and fibre concrete for application in engineering industry to manufacture gear and centrifugal pump casings.

Modeling and Analysis on the Rotation Accuracy of Lathe Spindle

2012 ◽  
Vol 602-604 ◽  
pp. 1757-1760
Author(s):  
Qiang Huang ◽  
Kun Wei
Keyword(s):  
Influence Factors ◽  
Cumulative Effect ◽  
Structure Characteristic ◽  
Analysis Method ◽  
Error Sources ◽  
Modeling And Analysis ◽  
Spindle Rotation ◽  
Machine Spindle ◽  
Center Track ◽  
The Impact

The rotation accuracy of the machine spindle is an important accuracy index, and has numerous influence factors. According to the structure characteristic of the spindle system, an integrated model of the spindle rotation error is established in this paper. By this model, the impact law and cumulative effect of various error sources on spindle rotation accuracy can be analyzed. Taking the lathe spindles as an example, the modeling and analysis method for spindle error are introduced. Visualization of spindle center track is achieved by programming.

How Dynamic Properties of Inverters Influence Electrode Metal Transfer to the Weld Pool, and Change Structural and Phase Composition of Welded Joints Produced via High Alloyed Electrodes

2018 ◽  
Vol 927 ◽  
pp. 93-98
Author(s):  
D.P. Il’yaschenko ◽  
Dmitry A. Chinakhov ◽  
R.A. Mamadaliev ◽  
V.I. Danilov ◽  
А.A. Saranchin
Keyword(s):  
Power Supply ◽  
Arc Welding ◽  
Dynamic Properties ◽  
Structural Systems ◽  
Metal Structures ◽  
Quality Literature ◽  
Welding Stability ◽  
Supply Equipment ◽  
The Impact ◽  
Electrode Metal

Covered-electrode arc welding has been currently widely-spread in assembly and maintenance technologies, as soon as it is a reliable tool, which helps get safe permanent joints in critical structural systems applied in Arctic. It is of burning importance to further enhance accuracy in methods which assess the impact of dynamic properties of power supply equipment with various forms of energy conversion on a consumable electrode welding stability and quality. Literature review [1–11] confirms that objectives, aimed at improving critical (in terms of extreme work and low temperatures) metal structures reliability, demand innovative approaches, i.e.:

scholarly journals Control of Bending-Bending Coupled Vibrations of a Rotating Thin-Walled Composite Beam

2015 ◽  
Vol 39 (4) ◽  
pp. 605-613 ◽  
Author(s):  
Jarosław Latalski ◽  
Marcin Bocheński ◽  
Jerzy Warmiński
Keyword(s):  
Composite Beam ◽  
Dynamic Properties ◽  
Control Strategies ◽  
Fiber Composite ◽  
Bending Moment ◽  
Piezoelectric Actuators ◽  
Transversely Isotropic ◽  
Cross Sectional ◽  
Modal Coupling ◽  
The Impact

Abstract The paper presents a study of a possible application of structure embedded piezoelectric actuators to enhance the performance of a rotating composite beam exhibiting the coupled flexural-flexural vibrations. The discussed transversal and lateral bending modal coupling results from the directional properties of the beam's laminate and ply stacking distribution. The mathematical model of the beam is based on an assumption of cross-sectional non-deformability and it incorporates a number of non-classical effects. The final 1-D governing equations of an active composite beam include both orthotropic properties of the laminate and transversely isotropic properties of piezoelectric layers. The system's control capabilities resulting from embedded Macro Fiber Composite piezoelectric actuators are represented by the boundary bending moment. To enhance the dynamic properties of the composite specimen under consideration a combination of linear proportional control strategies has been used. Comparison studies have been performed, including the impact on modal coupling magnitude and cross-over frequency shift.

Bridge Surface Roughness Identified from the Displacement Influence Lines of the Contact Points by Two Connected Vehicles

2020 ◽  
pp. 2043003
Author(s):  
Y. B. Yang ◽  
B. Q. Wang ◽  
Z. L. Wang ◽  
K. Shi ◽  
H. Xu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Surface Roughness ◽  
Dynamic Properties ◽  
Surface Profile ◽  
Connected Vehicles ◽  
The Finite Element Method ◽  
Contact Points ◽  
Continuous Beams ◽  
Static Correlation ◽  
The Impact

In this study, a new, effective procedure is proposed for identifying the surface roughness from the responses recorded of two connected test vehicles moving over the bridge. Central to this study is the proposal of a simple static correlation formula for relating the dynamic deflections of the two vehicles’s contact points on the bridge, via the displacement influence lines (DILs). With the aid of this relation, the roughness formula for estimating the bridge surface profile is derived using the responses of the leading and following vehicles. It does not require any prior knowledge of the dynamic properties of the bridge. The efficacy of the proposed procedure is validated for both the simple and three-span continuous beams by the finite element method (FEM). Also, a parametric study is conducted for various physical properties of the test vehicles. It is confirmed that the roughness profiles back-calculated from the proposed formula agree excellently with the assumed ones for both the simple and continuous beams. For use in practice, the two connected test vehicles should not be designed too heavy and not to move at too fast speeds, in order to reduce the impact on the bridge.

scholarly journals Bird-Strike Resistance of Composite Laminates with Different Materials

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 129 ◽  
Author(s):  
Yadong Zhou ◽  
Youchao Sun ◽  
Tianlin Huang
Keyword(s):  
Composite Materials ◽  
Composite Laminates ◽  
Impact Damage ◽  
Dynamic Properties ◽  
Dynamic Structure ◽  
Strength Properties ◽  
Bird Strike ◽  
Particle Hydrodynamics ◽  
Bird Impact ◽  
The Impact

To obtain some basic laws for bird-strike resistance of composite materials in aeronautical application, the high-velocity impact behaviors of composite laminates with different materials were studied by numerical methods. The smoothed particle hydrodynamics (SPH) and finite element method (FEM) coupling models were validated from various perspectives, and the numerical results were comparatively investigated. Results show that the different composite materials have relatively little effect on projectile deformations during the bird impact. However, the impact-damage distributions can be significantly different for different composite materials. The strength parameters and fracture energy parameters play different roles in different damage modes. Lastly, modal frequency was tentatively used to explain the damage behavior of the composite laminates, for it can manifest the mass and stiffness characteristics of a dynamic structure. The dynamic properties and strength properties jointly determine the impact-damage resistance of composite laminates under bird strike. Future optimization study can be considered from these two aspects.

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