ICME 2015 HW4

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Overview

This homework takes place at the mesoscale and macroscale and is separated into two parts:

• Crystal Plasticity (CP) using Abaqus and a user developed crystal plasticity finite element method
• MSU ISV Plasticity-Damage Model via DMGfit and Abaqus

All necessary input files and scripts are provided in the /cavs/general/Projects/ICME_2015/HW4/ directory. Move these files to your own directory (and make a backup copy) before trying to perform any simulations.

Use /scratch/"Your Directory" for best results.

Write a full report that follows a journal article manuscript format (include figures and tables in the text). Please double-space your document

Upon completion, upload a .pdf and .doc(x) file to your group folder in the ../ICME_2015/HW4/ directory. Be sure to also upload the requested files and plots from each section of the homework.

Objectives

• Run a multigrain crystal plasticity single finite element simulation
• Calibrate the macroscale Internal State Variable (ISV) model
• Run a one element finite simulation to verify the calibration

1. Crystal plasticity finite element calculations (upscaling for ISV plasticity calibration)

a. Run a one element finite element simulation in compression, tension, and torsion using crystal plasticity. Use a minimum of 180 grains to plot the stress-strain curves that will be used for calibrating the macroscale model.

b. Plot stress-strain curves for compression, tension, and torsion using an average of the polycrystalline aggregate from the three hardening sets determined in HW3.

c. Report your results.

2. ISV Plasticity Model Calibration

a. Use DMGfit to calibrate the MSU ISV Plasticity-Damage Model to the mesoscale polycrystalline plasticity stress-strain curve for nickel (see Figure 9.17 pg 401 in textbook). Plot all three stress-strain curves comparing the crystal plasticity results to the plasticity-damage ISV calibration results.

b. Run a one element simulation in ABAQUS with the DMG UMAT to verify the results from Part 1.

• Visit the Macroscale page and collect the user material (UMAT) and ABAQUS input file for aluminum in tension (implicit) OR obtain the input decks from the ICME2015 scratch folder
• Modify the input decks for compression, tension, and shear to reflect the calibrated parameters determined using DMGfit
• Open permissions on files

  chmod 755 *

• Enter the following software setup command in a terminal:

  swsetup abaqus

  (This can be added to your .bashrc file so that it loads automatically when logging into a compute node)
• Submit the abaqus job either locally or to Raptor using the following command:

  abaqus job=NAME_OF_INPUT user=NAME_OF_UMAT

• Do not include the file extension (.inp) in the "NAME_OF_INPUT".

c. Compare stress-strain results from the plasticity-damage ISV calibration to the verification results from the ABAQUS single finite element simulation.

d. Show the macroscale ISV constants and uncertainty values in the optimization of the calibration.

e. Report your results.

3. Room for Improvement

As with the previous homeworks, improve the tutorial(s) by adding/modifying the ICME website for:

1. Crystal Plasticity

2. MSU ISV Plasticity-Damage Model