Dear STKO Team,
Regarding the DamageTC3D Material, can you please explain me why in STKO the unit for the fracture energy (Gt and Gc) is force/area or force/volume, depends if the autoRegularization option is set to True, and in FIB the unit is force/length and do you convert the fracture energy into STKO units.
Thanks.
Best Regards,
Alexander
DamageTC3D Material
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diego.talledo
- Posts: 6
- Joined: Tue Feb 02, 2021 9:19 am
Re: DamageTC3D Material
Hi,
Fracture energy is defined as an energy per unit area. So basically it is [Force]*[Length]/[Length]^2. Thats why in Model code you find that in N/m (or equivalently in J/m2).
The area under a stress-strain curve is the specific fracture energy, so it is in [Force]/[Length]^2 (for instance N/m2) and it is equal to the fracture energy divided by the characteristic length.
When you use auto-regularization you give the fracture energy and the material calculates on his own the specific fracture energy. If you don't use auto-regularization, you need to give directly the specific fracture energy.
Just to make an example: fracture energy of a medium-good concrete is 100 N/m (see e.g. model-code 2010). If you work in N and mm, it corresponds to 0.1 N/mm. If you use auto-regularization you input 0.1 N/mm. Suppose you element size is 100 mm, the specific fracture energy is 0.1/100 = 0.001 N/mm2. If you don't use auto-regularization you input then 0.001 N/mm2.
Same concept applies for compressive fracture energy.
Hope it helps
Diego
Fracture energy is defined as an energy per unit area. So basically it is [Force]*[Length]/[Length]^2. Thats why in Model code you find that in N/m (or equivalently in J/m2).
The area under a stress-strain curve is the specific fracture energy, so it is in [Force]/[Length]^2 (for instance N/m2) and it is equal to the fracture energy divided by the characteristic length.
When you use auto-regularization you give the fracture energy and the material calculates on his own the specific fracture energy. If you don't use auto-regularization, you need to give directly the specific fracture energy.
Just to make an example: fracture energy of a medium-good concrete is 100 N/m (see e.g. model-code 2010). If you work in N and mm, it corresponds to 0.1 N/mm. If you use auto-regularization you input 0.1 N/mm. Suppose you element size is 100 mm, the specific fracture energy is 0.1/100 = 0.001 N/mm2. If you don't use auto-regularization you input then 0.001 N/mm2.
Same concept applies for compressive fracture energy.
Hope it helps
Diego
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Alexander Bogdan
- Posts: 4
- Joined: Wed Jul 28, 2021 7:09 am
Re: DamageTC3D Material
I understand now. Thank you very much, Diego
Alexander
Alexander