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.

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.

Towards fractional sensors

2018 ◽  
Vol 25 (1) ◽  
pp. 52-60 ◽  
Author(s):  
António M. Lopes ◽  
J. A. Tenreiro Machado ◽  
Alexandra M. Galhano
Keyword(s):  
Fractional Calculus ◽  
Fractional Order ◽  
Mechanical Systems ◽  
Modular Construction ◽  
Proper Selection ◽  
Micro Electro Mechanical Systems ◽  
Mechanical Structure ◽  
Mass Spring ◽  
Selection Of

This paper proposes a new sensor architecture inspired on the classical accelerometer and the fractional calculus. The fractional sensor (FS) adopts a modular construction with [Formula: see text] stages, where each stage consists of an association of mass–spring–damper elements. A proper selection of the elements in the global mechanical structure yields fractional-order characteristics. The frequency and time responses of the proposed apparatus are studied and compared with those exhibited by an ideal fractional order device. The FS can be implemented by means of modern fabrication techniques used with micro electro-mechanical systems.

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.

scholarly journals Inverse Task of Vibration Active Reduction of Mechanical Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Andrzej Dymarek ◽  
Tomasz Dzitkowski
Keyword(s):  
Free Vibration ◽  
Resonance Frequency ◽  
Dynamic Characteristics ◽  
Dynamic Properties ◽  
Vibration Reduction ◽  
Mechanical Systems ◽  
Graphic Method ◽  
Active Vibration

The paper presents the problem of discrete vibration reduction in mechanical systems depending on the desired dynamic properties. The conditions for physical feasibility of dynamic characteristics have been defined, in the form of impedance and mobility, for passive and active vibration reduction. The authors have presented a graphic method for determining the free vibration drop coefficient, based on the desired value of the reduced resonance frequency amplitude.

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.

Use of active synthesis in vibration reduction using an example of a four-storey building

2020 ◽  
Vol 26 (17-18) ◽  
pp. 1471-1483
Author(s):  
Andrzej Dymarek ◽  
Tomasz Dzitkowski ◽  
Krzysztof Herbuś ◽  
Piotr Ociepka ◽  
Agnieszka Sękala
Keyword(s):  
Characteristic Function ◽  
Dynamic Properties ◽  
Vibration Reduction ◽  
Rational Functions ◽  
Analytical Form ◽  
Active Force ◽  
Richter Scale ◽  
Active Vibration ◽  
The Impact ◽  
Storey Building

The article presents a method of active vibration reduction of vibrating mechanical systems. This method is based on the properties of positive rational functions, which in the case of discrete dynamical systems correspond to the characteristic function describing such systems. The method formalized uses methods for decomposing positive rational functions. The advantage of this approach is taking into account the analytical form of a characteristic function of the system being tested and the vibration-reducing force, as well as the conditions that the system should meet in the event of an active vibration-reducing force. In addition, in the proposed method, the desired dynamic properties of the system and the vibration-reducing force can be defined in such a way that the determined parameters of the active force affect all forms of the natural vibrations of the examined system. Based on the formalized methodology, the force reducing the vibrations of a four-storey frame to the desired displacement amplitude was determined. The impact of the place of application of the specific active force on the reduction of vibration of the tested object was also taken into account. The vibrations of the tested structure’s model were caused by kinematic excitation with a harmonic course and an amplitude corresponding to an earthquake of a magnitude of 5 on the Richter scale. To verify the determined force reducing the vibrations of the object and to create a visualisation of the analysed phenomenon, a dynamic analysis of the building structure was carried out using PLM Siemens NX 12 software.

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.

EVALUATION OF MECHANICAL SYSTEMS USED IN PERFUSION

1972 ◽  
Vol 68 (2_Supplb) ◽  
pp. S44-S73 ◽  
Author(s):  
Eugene F. Bernstein
Keyword(s):  
Mechanical Systems ◽  
Organ Perfusion ◽  
Critical Factors ◽  
System 2 ◽  
Common Problems ◽  
Mechanical Components ◽  
Perfusion Experiment ◽  
Selection Of

ABSTRACT Among the critical factors in organ perfusion are (1) the mechanical components of the system, (2) the composition of the perfusate, and (3) the perfusing conditions. In this review, particular consideration is given to the pump, the oxygenator, and cannulas in such systems. Emphasis is placed upon the selection of pertinent equipment for the goals of a particular perfusion experiment, based upon the criteria of adequacy of the perfusion. Common problems in organ perfusion are summarized, and potential solutions to the perfusion problem, involving either biologic or mechanical extracorporeal systems, are suggested.

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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