The Impact Damper as a Method of Improving Cantilever Boring Bars

1975 ◽  
Vol 97 (3) ◽  
pp. 859-866 ◽  
Author(s):  
M. D. Thomas ◽  
W. A. Knight ◽  
M. M. Sadek
Keyword(s):  
Theoretical Analysis ◽  
Forced Vibration ◽  
Metal Removal ◽  
Mass Ratio ◽  
Impact Damper ◽  
Boring Bar ◽  
Improved Design ◽  
Vibration Tests ◽  
The Impact ◽  
Vibrating Systems

The dynamic behavior of three different designs of a cantilever boring bar are compared by means of forced vibration tests. These are a bar with diametrically opposed flats machined along its length, a bar fabricated from laminates of steel and a damping compound, and a bar fitted with an impact damper. The impact damper boring bar is found to be the most effective, and an improved design, giving increases in stable metal removal rates of more than 100 percent, is outlined and tested. A theoretical analysis is presented for predicting the effectiveness of the impact damper with a spring supported impacting mass. This analysis enables the optimum mass ratio and gap setting of the damper to be selected for specified characteristics of the vibrating systems to which the damper is fitted.

Interval of restitution coefficient for chattering in impact damper

2021 ◽  
pp. 146134842110518
Author(s):  
Zongqi Li ◽  
Yanchen Du
Keyword(s):  
Frequency Ratio ◽  
Control Parameter ◽  
Coefficient Of Restitution ◽  
Restitution Coefficient ◽  
Mass Ratio ◽  
Collision System ◽  
Impact Damper ◽  
Periodic Movement ◽  
Movement Characteristics ◽  
The Impact

Based on the impact damper, a dynamic model of a non-fixed constrained collision system was established. The coefficient of restitution is used as the main control parameter to analyze the system’s periodic movement and its bifurcation region. The chattering movement characteristics of the system were revealed. The interval of restitution coefficient for the chattering of collision system under various mass ratio and frequency ratio was obtained. The results show that the chattering phenomenon occurs in the collision system when the coefficient of restitution is greater than 0.5; as the mass ratio decreases, the interval of restitution coefficient for chattering continues to expand; as the frequency increases, the interval of restitution coefficient for chattering narrows.

scholarly journals Analysis of the Effect of Conditions of Preparation of Nitrogen-Doped Activated Carbons Derived from Lotus Leaves by Activation with Sodium Amide on the Formation of Their Porous Structure

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1540
Author(s):  
Mirosław Kwiatkowski ◽  
Xin Hu
Keyword(s):  
Porous Structure ◽  
Activated Carbons ◽  
Structure Parameters ◽  
Mass Ratio ◽  
Nitrogen Doped ◽  
Adsorption Analysis ◽  
Lotus Leaves ◽  
The Impact ◽  
Sodium Amide ◽  
Numerical Clustering

This paper presents results of the analysis of the impact of activation temperature and mass ratio of activator to carbonized precursor R on the porous structure of nitrogen-doped activated carbons derived from lotus leaves by carbonization and chemical activation with sodium amide NaNH2. The analyses were carried out via the new numerical clustering-based adsorption analysis (LBET) method applied to nitrogen adsorption isotherms at −195.8 °C. On the basis of the results obtained it was shown that the amount of activator, as compared to activation temperatures, has a significantly greater influence on the formation of the porous structure of activated carbons. As shown in the study, the optimum values of the porous structure parameters are obtained for a mass ratio of R = 2. At a mass ratio of R = 3, a significant decrease in the values of the porous structure parameters was observed, indicating uncontrolled wall firing between adjacent micropores. The conducted analyses confirmed the validity of the new numerical clustering-based adsorption analysis (LBET) method, as it turned out that nitrogen-doped activated carbons prepared from lotus leaves are characterized by a high share of micropores and a significant degree of surface heterogeneity in most of the samples studied, which may, to some extent, undermine the reliability of the results obtained using classical methods of structure analysis that assume only a homogeneous pore structure.

An Investigation of the Vibration Testing Method for Small Diameter Endmills

2014 ◽  
Vol 625 ◽  
pp. 134-139
Author(s):  
Takenori Ono
Keyword(s):  
Small Diameter ◽  
Milling Process ◽  
Modal Parameters ◽  
Vibration Testing ◽  
Function Generator ◽  
Testing Method ◽  
Milling Tool ◽  
Compliance Curve ◽  
Vibration Tests ◽  
The Impact

This paper introduced about the in-process vibration testing method for small diameter endmill. By this method, the natural frequency and modal parameters such as mass, damping, and stiffness of the milling tool can be determined in the milling process. An oscillation of the vibrator is controlled by the function generator to apply the impact force at the appropriate cutting period. The measurement setup can determine the compliance curve by the measurement signals of the exiting force and tool deformation. To evaluate the feasibility of the new method, vibration tests were performed on a square endmill which has the diameter of 4 mm in the milling on brass material. Results of vibration tests show that modal parameters of the specific vibration mode can be determined by the new developed method.

FORCED VIBRATION TESTS AND THEORETICAL STUDIES ON DAMS.

1980 ◽  
Vol 69 (3) ◽  
pp. 605-634 ◽  
Author(s):  
RT SEVERN ◽  
AP JEARY ◽  
BR ELLIS ◽  
Keyword(s):  
Forced Vibration ◽  
Theoretical Studies ◽  
Vibration Tests

Psychological, Pedagogical and Drganizational Peculiarities of the Development of Students’ Volitional Qualities as a Factor of Success in Learning

2021 ◽  
Author(s):  
Nadiia Vientseva ◽  
◽  
Oleva Karapetrova
Keyword(s):  
Higher Education ◽  
Theoretical Analysis ◽  
Empirical Study ◽  
University Students ◽  
Education Institution ◽  
Educational Material ◽  
Academic Achievements ◽  
The Impact ◽  
The Relationship ◽  
Development Of Students

The article reports the results of the empirical study of the impact of volitional qualities development on the level of academic achievements of higher education institution students. The article gives a theoretical analysis of the main types of volitional qualities that affect the assimilation of educational material by students. There was established the level of their development and the relationship with academic achievements. The article also identifies the main psycho-pedagogical and organizational peculiarities that affect the success of mastering the knowledge by university students. The psychological and pedagogical recommendations for forming, developing and supporting the volitional sphere of students are developed.

Powered Two-Wheeler with Integrated Safety Using Recurdyn Multi-Body Dynamics

2014 ◽  
Vol 591 ◽  
pp. 193-196 ◽  
Author(s):  
B. Vijaya Ramnath ◽  
K. Venkataraman ◽  
Selvaraj Venkatram ◽  
Sohil Thomas ◽  
Muthukumarasamy Maheshwaran ◽  
...  
Keyword(s):  
Seat Belt ◽  
Body Dynamics ◽  
Holding Device ◽  
Depth Study ◽  
Improved Design ◽  
Accident Scenarios ◽  
Safety Considerations ◽  
Two Wheeler ◽  
Multi Body ◽  
The Impact

- Powered Two Wheelers (PTW) are very sensitive to environmental conditions and advancement in two-wheeler safety has not kept pace with the advancement in two-wheelers. The objective of our research is to bring about an improved design for powered two wheelers, analyzing the changes through simulation and thereby improving the safety considerations. According to the databases referred regarding accidents in depth study, it is observed that two-wheelers top the chart in number of accidents by a big margin and these accidents causes more fatal injuries. To save the rider, this paper proposes to constraint the rider along with pillion to the vehicle using “Leg holding device“ and seat belt. Side airbags are employed to absorb the impact of accident. The present safety system saves the rider in frontal collisions, while this research also focuses on side collisions. ISO 13232 standard accident scenarios were followed. For simulation of scenarios multi body dynamics software called RecurDyn is used. The improvement in employing safety measures is compared with its absence and results are plotted.

Dynamic analysis of two dimensional simply supported orthotropic bridge decks

1978 ◽  
Vol 5 (1) ◽  
pp. 58-69 ◽  
Author(s):  
G. G. Kulkarni ◽  
S. F. Ng
Keyword(s):  
Theoretical Analysis ◽  
Forced Vibration ◽  
Vibration Analysis ◽  
Bridge Decks ◽  
Two Dimensional ◽  
Amplification Factors ◽  
Simply Supported ◽  
Forced Vibration Analysis ◽  
Critical Sections

Forced vibration analysis of two dimensional bridge deck structures involves complex mathematical procedures and therefore analysis is often based on beam idealization of equivalent plates. This simplification yields close agreement only for long span bridges where plate action is relatively insignificant. However, such a concept of beam idealization cannot be successfully utilized in the case of short span bridges where plate action is predominant and where the determination of the distribution of dynamic deflections and amplification factors at critical sections of such plates is of prime concern. The principal objective of the present investigation is the forced vibration analysis of longitudinally stiffened, simply supported orthotropic bridge decks utilizing a new concept of interconnected beam idealization. The theoretical analysis deals with determination of amplification factors and dynamic deflections along critical sections of the plate treated as a series of interconnected beams. The aspect ratios of the plates under investigation as series of interconnected beams are designed to cover a wide range of plate to beam transition. The theoretical analysis is supplemented by an extensive experimental programme.In conclusion, it is seen that this concept of interconnected beam idealization not only takes into account the plate action of the deck structure but also reduces greatly the complexity of mathematical formulation. A good comparison between the theoretical and the experimental results indicates that this concept can be used to advantage for analysis and, within certain limitations, for design purposes.

Forced-Vibration Tests of the Daniel-Johnson Multiple-Arch Dam

2017 ◽  
pp. 397-408
Author(s):  
O. Gauron ◽  
Y. Boivin ◽  
S. Ambroise ◽  
P. Paultre ◽  
J. Proulx ◽  
...  
Keyword(s):  
Forced Vibration ◽  
Arch Dam ◽  
Vibration Tests

scholarly journals The Impact of Changing Environmental Conditions on the Retention of Heavy Metals Adsorbed by Pine Bark

2017 ◽  
pp. 278-284
Author(s):  
Oleksandr Khokhotva
Keyword(s):  
Heavy Metals ◽  
Environmental Conditions ◽  
Metal Removal ◽  
High Capacity ◽  
Pine Bark ◽  
Urea Solution ◽  
Metal Leaching ◽  
Total Efficiency ◽  
Runoff Water ◽  
The Impact

Landfills are widely used for the disposal of households' and industrial waste. Liquid landfill effluents contain heavy metals, are toxic to humans and ecosystems and have to be efficiently treated. One treatment option that is becoming popular is the reactive filter technology. The total efficiency of metal removal by a filter media greatly depends not only on adsorption itself, but also on the metal leaching from the adsorbent. The last parameter, in turn, may be dependant on changing environmental conditions since filters are usually located on open air and flow of contaminated water (landfill leachate, runoff water) has the intermittent nature. A filter material may dry, become frozen or stay wet, depending on a season. Previously adsorbed metals can leach from an adsorbent at the next flash of water, coming to water treatment facilities. Among others, pine bark has shown a high capacity to adsorb heavy metals from landfill leachates. In this study, pine bark has been pre-treated with urea-solution in order to increase its stability and adsorption properties. Within leaching experiments using either non-treated or pre-treated bark samples no significant influence of the changing environmental conditions on the extent of metal leaching was observed, though in most cases, metal leaching from wet bark samples exposed to freezing was somewhat higher. Zn leaching was the highest and Cu leaching the lowest for both NTB and UTB samples. The metal leaching from non-treated bark was several-fold higher compared to urea-treated bark. Possible mechanisms of barkurea interactions and reasons for enhanced metals adsorption by urea-modified bark are discussed.

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