scholarly journals Implementation of an Algorithm to Prevent Chatter Vibration in a CNC System

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3193 ◽  
Author(s):  
Marcin Jasiewicz ◽  
Karol Miądlicki
Keyword(s):  
Experimental Validation ◽  
Final Section ◽  
Dynamic Properties ◽  
Numerical Control ◽  
Chatter Vibration ◽  
Technological Parameters ◽  
Proper Selection ◽  
Receptance Coupling ◽  
Chatter Vibrations ◽  
Selection Of

Machining of shafts characterized by a high compliance is difficult due to the occurrence of self-excited chatter vibrations. It is possible to limit their occurrence through the appropriate selection of technological parameters. For a proper selection of these parameters it is necessary to know the dynamic properties of the machine–tool–workpiece. This study proposes an approach through which these properties can be determined as a result of the synthesis of the dynamic properties of the system, using the receptance coupling method. Knowledge of these properties allows us to select the technological parameters of the lathe using the assistance system integrated into the CNC (Computerized Numerical Control). The final section of this work presents the experimental validation of the assistant and proposed procedures.

Active Synthesis of Discrete Systems as a Tool for Reduction Vibration

2013 ◽  
Vol 198 ◽  
pp. 427-432 ◽  
Author(s):  
Andrzej Dymarek ◽  
Tomasz Dzitkowski
Keyword(s):  
Force Feedback ◽  
Dynamic Properties ◽  
Vibration Reduction ◽  
Mechanical Systems ◽  
Discrete Systems ◽  
Mechanical Effect ◽  
Active Force ◽  
Active Synthesis ◽  
Proper Selection ◽  
Selection Of

The paper presents the problem of vibration reduction in designed discrete mechanical systems. The method of reduction has been based on active synthesis, which makes it possible to obtain the desired mechanical effect through the proper selection of dynamic properties of the system, including the calculation of the active force as a function of the system force feedback.

Assessment of Dynamical Properties of Die Hammer MPM 10000 B Considering Deformations of Working Material

2008 ◽  
Vol 144 ◽  
pp. 71-76
Author(s):  
Ludwik Majewski ◽  
Arkadiusz Trąbka
Keyword(s):  
Numerical Simulations ◽  
Dynamic Properties ◽  
Graphical Form ◽  
Proper Selection ◽  
Low Level ◽  
Time Histories ◽  
Technical Specifications ◽  
Dynamical Properties ◽  
Selection Of ◽  
Calculation Models

This paper presents an assessment of dynamic properties of a die hammer. The object of research is the steam-air die hammer MPM 10000 B that is considered taking into account the deformations of the working material. Based upon the technical specifications, two calculation models of the hammer were developed assuring the proper selection of the parameters. Next, the numerical simulations were performed, which results were presented in a graphical form as time histories of displacements and accelerations of particular elements of the hammer. It was demonstrated that the analyzed design of a die hammer has sufficiently low level of vibration amplitudes as well as their accelerations.

Active Synthesis of Discrete Systems as a Tool for Stabilisation Vibration

2013 ◽  
Vol 307 ◽  
pp. 295-298 ◽  
Author(s):  
Tomasz Dzitkowski ◽  
Andrzej Dymarek
Keyword(s):  
Force Feedback ◽  
Dynamic Properties ◽  
Vibration Reduction ◽  
Mechanical Systems ◽  
Discrete Systems ◽  
Mechanical Effect ◽  
Active Force ◽  
Active Synthesis ◽  
Proper Selection ◽  
Selection Of

The paper presents the problem of stability and vibration reduction in designed discrete mechanical systems. The method of stabilisation and reduction has been based on active synthesis, which makes it possible to obtain the desired mechanical effect through the proper selection of dynamic properties of the system, including the calculation of the active force as a function of the system force feedback.

The Develop of Automatic Jet Electroplating Machining Gear Tool

2013 ◽  
Vol 568 ◽  
pp. 151-156
Author(s):  
Yong Yang ◽  
Min Kang ◽  
Xiu Qing Fu ◽  
Ying Wang
Keyword(s):  
Ph Value ◽  
Tooth Profile ◽  
Numerical Control ◽  
Technological Parameters ◽  
Solution Ph ◽  
Open Numerical Control System ◽  
Working Solution ◽  
Computer Based ◽  
Continuous Feeding ◽  
Selection Of

In order to solve the problem of automation electric plating gear surface, the numerical control electric plating machining tool was developed based on open numerical control system. The relative movement and velocity of anode nozzle was controlled by the motion control model. The selection of working solution and the continuous feeding liquid were achieved by use of the digital I/O module. The technological parameters, such as working current, the temperature of plating solution, PH value, and so on, were collected by the module of analog quantity acquisition and stored in the computer. Based on the preliminary experiments, the machine tool was reliable higher and the distribution of plating thickness on the tooth profile surface was uniform. The automatic electric plating technology was realized on the tooth profile surface.

Identification of a Lathe Spindle Dynamics Using Extended Inverse Receptance Coupling

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Marcin Jasiewicz ◽  
Bartosz Powałka
Keyword(s):  
Machine Tool ◽  
Degrees Of Freedom ◽  
Experimental Validation ◽  
Dynamic Properties ◽  
Measurement Procedure ◽  
Experimental Models ◽  
Analytical Models ◽  
Receptance Coupling ◽  
Spindle Dynamics ◽  
Rotational Degrees Of Freedom

In order to ensure machining stability, it is essential to properly determine the dynamic properties of machine tool–workpiece system. Experimental modal analysis provides good results; however, due to high time consumption, in some cases, its use is not practically justified. Then, a receptance coupling method can be used, that allows for the synthesis of the experimental models of the machine tool components and analytical models of the workpiece. However, a significant disadvantage of this method is the need for the experimental identification of the rotational degrees-of-freedom, fully defining dynamic properties of the spindle. This paper presents an improved method based on inverse receptance coupling, which enables effective identification of the spindle dynamics with the properties of the joint. Then, a measurement procedure and results of the experimental validation are presented.

Analyzing chatter vibration during turning on computer numerical control lathe using ensemble local mean decomposition and probabilistic approach

2021 ◽  
Vol 52 (6) ◽  
pp. 168-180
Author(s):  
Pankaj Gupta ◽  
Bhagat Singh
Keyword(s):  
Probability Distribution ◽  
Probabilistic Approach ◽  
Numerical Control ◽  
Chatter Vibration ◽  
Signal Processing Technique ◽  
Local Mean Decomposition ◽  
Incipient Stage ◽  
Local Mean ◽  
Selection Of ◽  
Tool Chatter

Chatter vibration is an undesired and indispensable phenomenon in turning operation, which cannot be completely avoided. However, it can be suppressed by early identification and with the proper choice of input turning parameters. The key issue of chatter detection is to process the acquired signals and extract the features pertaining to it. In the present work, a methodology has been proposed for exploring tool chatter features in the incipient stage during turning on lathe. Chatter signals generated during the turning of Al 6061-T6 have been acquired using a microphone. A stability lobe diagram has been plotted to access the stability regime. Further, in order to study the effect of feed rate on stability, the recorded signals have been processed using a local mean decomposition signal processing technique, followed by the selection of dominating product functions using the Fourier transform. The decomposed signals have been used to evaluate the new output parameter, that is, chatter index. Further, the Nakagami probability distribution has been used to ascertain stability region (threshold). From the experimental validation, it has been inferred that cutting combinations obtained from the Nakagami probability distribution are significant and capable of limiting chatter vibrations. The present methodology will serve as guidelines to the researchers and machinist for the identification of tool chatter in the incipient stage, explore its severity, and finally suppress it with the proper selection of input turning parameters.

Meriel Talbot and the Society for the Overseas Settlement of British Women, 1919–1937

2017 ◽  
Vol 10 (1) ◽  
pp. 32-52
Author(s):  
Bonnie White
Keyword(s):  
Domestic Service ◽  
Agricultural Workers ◽  
British Government ◽  
Early Failure ◽  
Proper Selection ◽  
Domestic Servants ◽  
Female Workers ◽  
Female Migrants ◽  
Post War ◽  
Selection Of

In 1917 the British government began making plans for post-war adjustments to the economy, which included the migration of surplus women to the dominions. The Society for the Overseas Settlement of British Women was established in 1920 to facilitate the migration of female workers to the dominions. Earlier studies have argued that overseas emigration efforts purposefully directed women into domestic service as surplus commodities, thus alleviating the female ‘surplus’ and easing economic hardships of the post-war period. This article argues that as Publicity Officer for the SOSBW, Meriel Talbot targeted women she believed would be ideal candidates for emigration, including former members of the Women's Land Army and affiliated groups. With the proper selection of female migrants, Talbot sought to expand work opportunities for women in the dominions beyond domestic service, while reducing the female surplus at home and servicing the connection between state and empire. Dominion authorities, whose demands for migrant labour vacillated between agricultural workers during the war years and domestic servants after 1920, disapproved of Talbot's efforts to migrate women for work in agriculture. Divergent policies led to the early failure of the SOSBW in 1923.

KINEMATIC FEATURES OF THE LAPPING PROCESS AND DETERMINATION OF ITS BASIC PARAMETERS

2020 ◽  
Vol 7 (3) ◽  
pp. 23-28
Author(s):  
EZIZ SARVAN SHIRVAN ◽  
Keyword(s):  
Dynamic Properties ◽  
Cutting Speed ◽  
Equilibrium System ◽  
Technological Parameters ◽  
Kinematic Characteristics ◽  
Angular Velocities ◽  
Basic Parameters ◽  
Grinding Tool ◽  
Mathematical Relationships ◽  
Analytical Expressions

This paper discusses the kinematic characteristics of lapping process and the main parameters of the process. It was determined that the influencing degree of technological parameters to the forming surface and processes. It was projected the construction of the lapping head for processing of internal cylindrical surfaces, scheme of the lapping operation and graphic description of the forces influencing. The relationships between the axial, radial and tangential cutting forces and the effect of the combined force thereof are determined in order to ensure the necessary surface pressure. During the analysis geometric and mathematical relationships were obtained. The extracted analytical expressions can be realized by further experimental researches and can be used in engineering calculations of technological parameters of processing by lapping. Angular velocity, friction force, linear velocity, also the length of the tactile curve and the radius of the part can be considered the main kinematic and dynamic parameters of the process that the formation of the surface, also the course of the process depends on these parameters. Depending on the kinematic parameters, the wear nature of the tool changes and this changes the linear and angular velocities, which have a significant impact on the accuracy, quality and productivity of processing. When examining the technological capabilities of the process, the nature of the movement between the part and the grinding tool, also changes in cutting speed are often considered as a main factor. Analytical expressions were obtained to determine the main parameters of the process, taking into account the kinematic characteristics of the friction process. These expressions can be used in engineering calculations and allow to determine the optimal values of the processing mode. In order to obtain the required micrometric surface cleanliness and measurement accuracy, correlation relationships were established between the main parameters of the process, equations of the equilibrium system of shear forces were compiled and analytical expressions were obtained based on the analysis of kinematic and dynamic properties of the system.

scholarly journals The research of dynamic impacts on the hydraulic structure foundation base, transformed in the process of accident recovery

2018 ◽  
Vol 251 ◽  
pp. 04040
Author(s):  
Zaven Ter-Martirosyan ◽  
Ivan Luzin
Keyword(s):  
Field Experiments ◽  
Dynamic Properties ◽  
Soil Parameters ◽  
Experimental Site ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Foundation Base ◽  
Dynamic Impacts ◽  
Scale Experiment ◽  
Selection Of

The article presents the results of a comprehensive research of the dynamic impacts on a modified base. The modified base was obtained as a result of compensatory injection at the experimental site for the accident recovery at the hydraulic engineering structure. The complex study of the dynamic impacts includes special laboratory tests to determine the soil parameters, the finite element analysis of the experimental site, taking into account the dynamic properties, the selection of the necessary equipment for field experiments based on the numerical solution results, a full-scale experiment with the measurement of the foundation sediments of the experimental site.

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