Test Machine and Control System Interactions in the Evaluation of Rate-Dependent Metal Flow

[+] Author and Article Information
S. B. Brown, V. R. Dave

Massachusetts Institute of Technology, Cambridge, MA 02139

J. Eng. Mater. Technol 115(2), 179-186 (Apr 01, 1993) (8 pages) doi:10.1115/1.2904204 History: Received January 29, 1991; Revised August 19, 1992; Online April 29, 2008


Although rate-change experiments are essential for characterizing rate-dependent flow, certain nonobvious aspects of test machine dynamic response and control system strategies can distort rate-change data. These distortions are large enough to cause rate-change experiments to characterize the test system dynamic response instead of the test material’s rate dependence. We demonstrate that both relaxation and strain rate change experiments exhibit this potential distortion of test data. Investigators performing these experiments must therefore examine control error carefully to assure that the experiments are valid. We demonstrate that the standard PID control modes normally used in servocontrolled mechanical test equipment will generate error. Either P or PD control modes are more appropriate for rate-change experiments.

Copyright © 1993 by The American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.





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