Anomalous Frictional Behavior in Collisions of Thin

نویسندگان

  • John Calsamiglia
  • Scott W. Kennedy
  • Anindya Chatterjee
  • Andy L. Ruina
  • James T. Jenkins
چکیده

We report collision experiments with Delrin disks and a steel plate. The disks floated air table, and collided at low speeds with a thick plate clamped to the table. The collisio was varied. The observed normal restitution was consistent with other studies. The fri interaction di ered from that reported for spheres and thick disks, and from predict standard rigid-body collision models. For ‘sliding’ 2D collisions, most authors assume the ratio of tangential to normal equals (friction coe cient). The observed impulse ratio was appreciably lower: roughl =2 slightly into the sliding regime, approaching only for grazing collisions. Separate experiments were conducted to estimate ; check its invariance with force magnitude; and check that the anomalies observed are not from dependence on velocity magnitude. We connect our ndings with the nature of deformation elds in disks, and with ‘fo response’ and ‘impulse-response’ rigidity. Submitted to Journal of Applied Mechanics, July, 1997. To appear in proceedings of ASME Winter Meeting, Dallas, TX. Nov., 1997.

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تاریخ انتشار 1997