Constitutive Modelling of Soils under High Strain Rates – Theoretical, Numerical, and Experimental Results

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Authors
  1. Xia, K.
  2. Jafari, M.
  3. Kanopoulos, P.P.
  4. Wei, Y.
Corporate Authors
Defence Research and Development Canada, Valcartier Research Centre, Quebec QC (CAN);Toronto Univ, Toronto ONT (CAN) Dept of Civil Engineering
Abstract
The following report briefly outlines the concept of Perzyna-type viscoplasticity and its underlying constitutive equations that describe the nonlinear stress-strain relations of rate-dependant materials in the generalized tensor framework. Following the theoretical development, a numerical algorithm that computes the stress increment based on known a strain increment is presented. This algorithm is suitable for implementation into finite element codes (including hydrocodes such as LS-DYNA). Experimental stress-strain results from fine and coarse grained soils ranging from strain rates of 100 s-1 to 2100 s-1 are presented. The constitutive equations are calibrated against the experimental data using the Marquardt-Levenberg nonlinear optimisation algorithm. The material constants provided as a result of the calibration are suitable for implementation in hydrocodes, provided similar material types and conditions are being modelled over strain rates within the same orders of magnitude of the testing. A three phase equation of state is presented both in the theoretical form and in a numerically appropriate pseudocode. The numerical code returns changes in pressure based on prescribed changes in volume, or computes an updated material bulk modulus. Parameters for the three phase model are derived from the literature for various sand types and degrees of saturation. Finally, the constitutive model (both in the volumetric/deviator and devi
Keywords
simulation soil model
Report Number
DRDC-RDDC-2015-C071 — Contract Report
Date of publication
01 Mar 2015
Number of Pages
97
DSTKIM No
CA040668
CANDIS No
801801
Format(s):
Electronic Document(PDF)

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