0
Research Papers

Dynamic Modeling of Damping Effects in Highly Damped Compliant Fingers for Applications Involving Contacts

[+] Author and Article Information
Chih-Hsing Liu

 Singapore Institute of Manufacturing Technology, Singapore 638075 chliu@simtech.a-star.edu.sg

Kok-Meng Lee1

 The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 –0405 kokmeng.lee@me.gatech.edu

1

Corresponding author.

J. Dyn. Sys., Meas., Control 134(1), 011005 (Dec 02, 2011) (9 pages) doi:10.1115/1.4005270 History: Received July 02, 2010; Revised July 31, 2011; Published December 02, 2011; Online December 02, 2011

In many industries, it is often required to transfer objects using compliant fingers capable of accommodating a limited range of object shapes/sizes without causing damage to the products being handled. This paper presents a coupled computational and experimental method in time domain to characterize the damping coefficient of a continuum structure, particularly, its applications for analyzing the damping effect of a highly damped compliant finger on contact-induced forces and stresses. With the aid of Rayleigh damping and explicit dynamic finite element analysis (FEA), this method relaxes several limitations of commonly used damping identification methods (such as log-decrement and half-power methods) that are valid for systems with an oscillatory response and generally estimate the damping ratio for a lumped parameter model. This damping identification method implemented using off-the-shelf commercial FEA packages has been validated by comparing results against published data; both oscillatory and nonoscillatory responses are considered. Along with a detailed discussion on practical issues commonly encountered in explicit dynamic FEA for damping identification, the effects of damping coefficients on contact between a rotating compliant finger and an elliptical object has been numerically investigated and experimentally validated. The findings offer a better understanding for improving grasper designs for applications where joint-less compliant fingers are advantageous.

FIGURES IN THIS ARTICLE
<>
Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Frequency effect of proportional damping on damping ratio

Grahic Jump Location
Figure 2

Coupled computational and experimental damping identification (CCEDI) method

Grahic Jump Location
Figure 3

Impulse response with initial guessed and critical damping coefficients (αcr  = 30 s−1 , ζ= 0.0055)

Grahic Jump Location
Figure 4

Comparison of simulation and published experimental data (α = αcr ζ = 0.165 s−1 )

Grahic Jump Location
Figure 5

Setup for damping identification of the compliant finger

Grahic Jump Location
Figure 6

Effect of FEA models (4.5-in. finger, α = 180 s−1 )

Grahic Jump Location
Figure 7

Effect of α on tip response (4.5-in finger)

Grahic Jump Location
Figure 8

Damping coefficients of compliant fingers

Grahic Jump Location
Figure 9

Experiment Setup for simulating contact between rotating finger and elliptical object

Grahic Jump Location
Figure 10

Reaction force from the contact between rotating finger and elliptical object

Grahic Jump Location
Figure 11

Simulation and experimental results of finger-contact deformation

Grahic Jump Location
Figure 12

Simulated snapshots illustrating the finger deformation (α = 180 s−1 )

Grahic Jump Location
Figure 13

Initial and final contact (α = 7.5, 180 and 600 s−1 )

Grahic Jump Location
Figure 14

Effect of finger damping coefficient on maximum finger/object stresses and reaction force

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In