The reason to split this example into several sub-posts is to try to be as clear as possible. And to keep any videos shorter and more manageable.
CDM = Continuum Damage Mechanics, aka Ductile Damage of Metals
Test data used for Step1a: the smooth uniaxial dogbone specimen test data truncated at ultimate.
Why: So we can use numerical mode (much faster than FE-mode) to get an initial calibration established.
Test data used for Step1b: the smooth uniaxial dogbone specimen test data all the way to incipient failure.
Target Material Model: Mises Elasto-Plasticity
Target Hardening Curve: Swift-Voce. The challenge here is that many hardening curves may fit this data when truncated at ultimate. Then that hardening curve type may not fit so well from ultimate to damage initiation. In practice, most people are going to try a few alternatives here in this stage. Reading through the CDM literature, we noticed that many researchers mentioned using the four hardening curve equational forms in the red box below. The Swift-Voce (linear combination of Swift and Voce) seemed to be the most successful, so we will focus on that form here.
From the docs:
If alpha=1, this degenerates to the Swift law, alpha=0 degenerates to the Voce law.
These 4 equational forms do not exist in the Abaqus solver, so they will be written to the solver as tabular. The user will give 3 additional values to guide the tabularization. Setting the distribution bias = 0 gives a uniform spacing of points along the hardening curve, as this value is set > 0 the spacing is biased to provide more points at the beginning of the hardening curve. The user can visualize the hardening curve using the icon highlighted in the green box.
The video below was created on April 22, 2022 using R2022x, HotFix 1.25
This image is taken at the end of the video:
Here is the zipped 3dxml file as saved at the end of this Step1ab:
Back to: Continuum Damage Mechanics: Worked Example
Back to: Continuum Damage Mechanics: References
Back to: Sharing Material Test Data
Back to: Material Modeling and Calibration - An Overview and Curriculum
