0
Technical Brief

On the Importance of Displacement History in Soft-Body Contact Models

[+] Author and Article Information
Jonathan Fleischmann

Simulation Based Engineering Laboratory (SBEL),
Department of Mechanical Engineering,
University of Wisconsin-Madison,
Madison, WI 53706
e-mail: jafleisc@wisc.edu

Radu Serban

Simulation Based Engineering Laboratory (SBEL),
Department of Mechanical Engineering,
University of Wisconsin-Madison,
Madison, WI 53706
e-mail: serban@wisc.edu

Dan Negrut

Simulation Based Engineering Laboratory (SBEL),
Department of Mechanical Engineering,
University of Wisconsin-Madison,
Madison, WI 53706
e-mail: negrut@wisc.edu

Paramsothy Jayakumar

U.S. Army Tank Automotive Research Development
and Engineering Center (TARDEC),
Warren, MI 48397
e-mail: paramsothy.jayakumar.civ@mail.mil

1Corresponding author.

Contributed by the Design Engineering Division of ASME for publication in the JOURNAL OF COMPUTATIONAL AND NONLINEAR DYNAMICS. Manuscript received June 13, 2015; final manuscript received July 29, 2015; published online November 13, 2015. Assoc. Editor: Javier Cuadrado.This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States. Approved for public release; distribution is unlimited.

J. Comput. Nonlinear Dynam 11(4), 044502 (Nov 13, 2015) (5 pages) Paper No: CND-15-1164; doi: 10.1115/1.4031197 History: Received June 13, 2015; Revised July 29, 2015

Two approaches are commonly used for handling frictional contact within the framework of the discrete element method (DEM). One relies on the complementarity method (CM) to enforce a nonpenetration condition and the Coulomb dry-friction model at the interface between two bodies in mutual contact. The second approach, called the penalty method (PM), invokes an elasticity argument to produce a frictional contact force that factors in the local deformation and relative motion of the bodies in contact. We give a brief presentation of a DEM-PM contact model that includes multi-time-step tangential contact displacement history. We show that its implementation in an open-source simulation capability called Chrono is capable of accurately reproducing results from physical tests typical of the field of geomechanics, i.e., direct shear tests on a monodisperse material. Keeping track of the tangential contact displacement history emerges as a key element of the model. We show that identical simulations using contact models that include either no tangential contact displacement history or only single-time-step tangential contact displacement history are unable to accurately model the direct shear test.

FIGURES IN THIS ARTICLE
<>
Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

DEM-PM contact model described in this section, with normal overlap distance δn, contact–normal unit vector n, and tangential displacement vector ut in the plane of contact (top), and with a Hookean-linear contact force–displacement law with constant Coulomb sliding friction (bottom)

Grahic Jump Location
Fig. 2

Direct shear simulation setup (top) and shear versus displacement results (bottom) obtained by Chrono [14] and LIGGGHTS [15] for 1800 randomly packed uniform spheres using the true tangential contact displacement history model of Eq. (4), the pseudohistory model of Eq. (5), and no tangential contact history

Grahic Jump Location
Fig. 3

Direct shear test results for 5000 randomly packed uniform glass beads obtained by experiment [30] (top) and DEM-PM simulations using Chrono (center and bottom), under constant normal stresses of 3.1, 6.4, 12.5, and 24.2 kPa. For the DEM-PM simulations, elastic moduli of E = 4(106) Pa (center) and E = 4(107) Pa (bottom) are used.

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