An experimental study of a multi-particle impact damper

2009 ◽  
Vol 223 (9) ◽  
pp. 2029-2038 ◽  
Author(s):  
M Trigui ◽  
E Foltete ◽  
M S Abbes ◽  
T Fakhfakh ◽  
N Bouhaddi ◽  
...  
Keyword(s):  
Experimental Study ◽  
Damping Capacity ◽  
Particle Impact ◽  
Structural Damping ◽  
Impact Damper ◽  
System Parameters ◽  
Specific Damping Capacity ◽  
Free Beam ◽  
Specific Impact ◽  
Impact Damping

In this article, an experimental study of a vertical particle impact damper under free excitation is investigated. Specific impact damping is determined for a primary structure (clamped-free beam) with an enclosure attached to its free end and containing a lead particle. The influence of some system parameters such as clearance and intensity of excitation are investigated. An analytical model based on the concept of an equivalent system with impacting mass is presented and used to compute the specific impact damping. Driven by the experimental observation, it has been shown that a high value of specific damping capacity was reached with a particle impact damper. The obtained results prove the efficiency of this process for achieving high structural damping.

Experimental study of passive vibration suppression using absorber with spherical ball impact damper

2016 ◽  
Vol 231 (17) ◽  
pp. 3193-3201 ◽  
Author(s):  
Riadh Chaari ◽  
Fathi Djemal ◽  
Fakher Chaari ◽  
Mohamed Slim Abbes ◽  
Mohamed Haddar
Keyword(s):  
Vibration Suppression ◽  
Industrial Applications ◽  
Design Parameters ◽  
Particle Impact ◽  
Ball Impact ◽  
Impact Damper ◽  
Ball Size ◽  
Wide Range ◽  
The Impact ◽  
Impact Damping

Impact dampers are efficient in many industrial applications with a wide range of frequencies. An experimental analysis of the impact damping of spherical balls is investigated to simplify the particle impact damping design and improve the vibration suppression. The objective of the study is to analyze some of the design parameters of impact damper using spherical balls. The experimental investigation consists to test the effect of the ball size for each mass level, the number of balls for each size level and different exciting force levels on vibrations of the main structure. The parametric study provided useful information to understand and optimize Particle Impact Damping design.

Particle Impact Damping in Two Dimensions

2009 ◽  
Vol 413-414 ◽  
pp. 415-422 ◽  
Author(s):  
Riaz Ahmad Bhatti ◽  
Yan Rong Wang ◽  
Zhou Cheng Wang
Keyword(s):  
Two Dimensions ◽  
Particle Impact ◽  
Structural Damping ◽  
Metallic Particles ◽  
Acceleration Amplitude ◽  
Oblique Impacts ◽  
Impact Phenomena ◽  
Linear Damping ◽  
Good Agreement ◽  
Impact Damping

Particle impact damping (PID) is a technique of achieving high structural damping with small metallic particles embedded within a cavity that is attached to vibrating structure. This is a highly non-linear damping mechanism in which energy dissipation is primarily related to friction and impact phenomena. In this work a simple yet detailed analytical model is presented to study PID in two dimensions under transient vibrations. Normal as well as oblique impacts are considered. The effect of cavity size and acceleration amplitude on PID is studied and the results are supported by experiments. Fairly good agreement is found between the theory and the experiment.

Dynamics and Performance of a Harmonically Excited Vertical Impact Damper

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Sanjiv Ramachandran ◽  
George Lesieutre
Keyword(s):  
Loss Factor ◽  
Vertical Direction ◽  
Theoretical Models ◽  
Coefficient Of Restitution ◽  
Numerical Continuation ◽  
Particle Impact ◽  
Impact Damper ◽  
High Loss ◽  
Wide Range ◽  
And Performance

Particle impact dampers (PIDs) have been shown to be effective in vibration damping. However, our understanding of such dampers is still limited, based on the theoretical models existing today. Predicting the performance of the PID is an important problem, which needs to be investigated more thoroughly. This research seeks to understand the dynamics of a PID as well as those parameters which govern its behavior. The system investigated is a particle impact damper with a ceiling, under the influence of gravity. The base is harmonically excited in the vertical direction. A two-dimensional discrete map is obtained, wherein the variables at one impact uniquely dictate the variables at the next impact. This map is solved using a numerical continuation procedure. Periodic impact motions and “irregular” motions are observed. The effects of various parameters such as the gap clearance, coefficient of restitution, and the base acceleration are analyzed. The dependence of the effective damping loss factor on these parameters is also studied. The loss factor results indicate peak damping for certain combinations of parameters. These combinations of parameters correspond to a region in parameter space where two-impacts-per-cycle motions are observed over a wide range of nondimensional base accelerations. The value of the nondimensional acceleration at which the onset of two-impacts-per-cycle solutions occurs depends on the nondimensional gap clearance and the coefficient of restitution. The range of nondimensional gap clearances over which two-impacts-per-cycle solutions are observed increases as the coefficient of restitution increases. In the regime of two-impacts-per-cycle solutions, the value of nondimensional base acceleration corresponding to onset of these solutions initially decreases and then increases with increasing nondimensional gap clearance. As the two-impacts-per-cycle solutions are associated with high loss factors that are relatively insensitive to changing conditions, they are of great interest to the designer.

Modeling the fine particle impact damper

2010 ◽  
Vol 52 (7) ◽  
pp. 1015-1022 ◽  
Author(s):  
Yanchen Du ◽  
Shulin Wang
Keyword(s):  
Fine Particle ◽  
Particle Impact ◽  
Impact Damper

Assessment of Internal Damping in Uniaxially Stressed Metals: Exponential and Autoregressive Methods

1998 ◽  
Vol 120 (2) ◽  
pp. 177-184 ◽  
Author(s):  
A. L. Audenino ◽  
E. M. Zanetti ◽  
P. M. Calderale
Keyword(s):  
Nonlinear Behavior ◽  
Least Square ◽  
Dissipated Energy ◽  
Exponential Fitting ◽  
Damping Capacity ◽  
Test Machine ◽  
Internal Damping ◽  
Cast Irons ◽  
Decay Signal ◽  
Specific Damping Capacity

When a metallic material is highly stressed, its internal specific damping capacity increases showing a nonlinear behavior. In spite of this, the most part of experimental methods employ nonhomogeneous stress fields measuring only a volumetric average, often called structural damping. To overcome this problem the procedure herein presented extends the applicability of the plain traction or compression methods to higher frequency range (up to 300 Hz). The introduced methodology corrects for elastic energy and dissipated energy relative to the test machine and to the fixtures. The experimental procedure is based on the acquisition of a decay signal when the test machine excitation force has been removed. Two different methods to extract the pattern of internal damping versus material strain have been compared: one is based on least square exponential fitting while the other employs an autoregressive model. Best results have been obtained combining the two techniques taking into account also the variation of Young’s modulus with strain. The resulting curves of the loss factor as a function of strain amplitude for three steels and two cast irons are presented.

scholarly journals EXPERIMENTAL ANALYSIS OF STRUCTURAL DAMPING FOR BOLTED AND WELDED SPLICE CONNECTION JOINT FOR IPE-80 STEEL PROFILE

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Ognjen Mijatović ◽  
Zoran Mišković ◽  
Ratko Salatić ◽  
Rastislav Mandić ◽  
Valentina Golubović-Bugarski ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Experimental Analysis ◽  
Damping Capacity ◽  
Dynamic Problems ◽  
Structural Damping ◽  
Structural Joints

Progress and demands of all types of constructions imposed the need for the development of modernstructures that are lightweight, but at the same time have high damping capacity and stiffness. Theconsequences of these requirements are increased dynamic problems related to vibrations anddissipative processes in structure connection joints. Structural joints are the main reason for thesignificant reduction of the level of energy dissipation and source of structural damping so thereforethey have become a subject of interest to many researchers. The aim of this paper is to present someproblems regarding research of structural damping and the importance of study Contact Mechanicsto better understand the problem of structural damping.

An Experimental Study on the Influence of Structural Damping on Internal Fluid Pressure During a Transient Flow

1990 ◽  
Vol 112 (3) ◽  
pp. 284-290 ◽  
Author(s):  
D. D. Budny ◽  
F. J. Hatfield ◽  
D. C. Wiggert
Keyword(s):  
Experimental Study ◽  
Transient Flow ◽  
Traditional Approach ◽  
Dynamic Pressure ◽  
Fluid Pressure ◽  
Piping System ◽  
Internal Dynamic ◽  
Structural Damping ◽  
Pipe System ◽  
Internal Fluid

The traditional approach to designing a piping system subject to internal dynamic pressure is to restrain the piping as much as possible, and the approximation made in the analysis is to assume no contribution of structural energy dissipation. To determine the validity of this concept and approximation, an experimental study of a piping system was performed to measure the influence of structural damping. A pipe system was designed with a loop that could be turned so that its natural frequency would match that of the contained liquid. It was discovered that a properly sized damper on the piping loop greatly accelerates the decay of the fluid pressure transient. The damper absorbs some energy from the piping, reducing the resulting rebound fluid pressure. When the loop is subjected to forced steady-state vibration, there is a fluid pressure response. The amplitude of that pressure can be reduced by installing an external damper: the stiffer the damper the more effective it is in reducing dynamic pressure.

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