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laws:vmvp [2024/11/29 15:46] carlos [VMVP: viscoplasticity] |
laws:vmvp [2024/11/29 15:53] (current) carlos [VMVP: formulation generalities] |
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$\Phi = J_{2}(\underline{\tilde{\sigma}}-\underline{\mathbb{X}})-\sigma_{y}-R \leq 0$\\ | $\Phi = J_{2}(\underline{\tilde{\sigma}}-\underline{\mathbb{X}})-\sigma_{y}-R \leq 0$\\ | ||
- | where:\\ | + | >where: |
- | * $\sigma_{y}$ is the yield stress of the material.\\ | + | >* $\sigma_{y}$ is the yield stress of the material. |
- | * $R$ is the isotorpic hardening, calculated as the Voce iso. hardening law:\\ | + | >* $R$ is the isotorpic hardening, calculated as the Voce iso. hardening law: |
- | $\dot{R} = -b\cdot (Q-R)\cdot \dot{p} \hspace{1cm} -> \hspace{1cm} R(p)=Q\cdot (1-\exp(-b\cdot p))$\\ where $p$ is the equivalent plastic strain $(-)$, and $\dot{p}$ is the equivalent plastic strain rate $(s^{-1})$\\ | + | >$\hspace{1cm} \dot{R} = -b\cdot (Q-R)\cdot \dot{p} \hspace{1cm} -> \hspace{1cm} R(p)=Q\cdot (1-\exp(-b\cdot p))$\\ where $p$ is the equivalent plastic strain $(-)$, and $\dot{p}$ is the equivalent plastic strain rate $(s^{-1})$\\ |
Inheriting the classical Chaboche-type formulation, the backstress tensor $\underline{\mathbb{X}}$ is calculated as the sum of a total of $nAF$ user-defined Armstrong-Frederick (AF) backstress equations. \\ | Inheriting the classical Chaboche-type formulation, the backstress tensor $\underline{\mathbb{X}}$ is calculated as the sum of a total of $nAF$ user-defined Armstrong-Frederick (AF) backstress equations. \\ | ||
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>> · $\underline{\tilde{\sigma}}_{k+1}=\underline{\sigma}_{k+1} \cdot (1-D_{k})^{-1}$ | >> · $\underline{\tilde{\sigma}}_{k+1}=\underline{\sigma}_{k+1} \cdot (1-D_{k})^{-1}$ | ||
>> · $D_{k+1}=f \Bigl( \underline{\sigma}_{k+1}, D_{k},... \Bigr)$\\ | >> · $D_{k+1}=f \Bigl( \underline{\sigma}_{k+1}, D_{k},... \Bigr)$\\ | ||
- | > **dam_type = 3** Fully-coupled damage. | + | > **dam_type = 2** Fully-coupled damage. |
>In this final case, the damage equations are included within the big Jacobian unknown set of equations, and are solved together with all the system in an implicit manner. It is a time-consuming and computationally heavy approach, where: | >In this final case, the damage equations are included within the big Jacobian unknown set of equations, and are solved together with all the system in an implicit manner. It is a time-consuming and computationally heavy approach, where: | ||
>> · $\underline{\tilde{\sigma}}_{k+1}=\underline{\sigma}_{k+1} \cdot (1-D_{k+1})^{-1}$ | >> · $\underline{\tilde{\sigma}}_{k+1}=\underline{\sigma}_{k+1} \cdot (1-D_{k+1})^{-1}$ | ||
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^Line 01; format (2I5, 60A1)^^ | ^Line 01; format (2I5, 60A1)^^ | ||
|IL|Law number| | |IL|Law number| | ||
- | |ITYPE| 271| | + | |ITYPE| 282| |
|COMMENT| Any comment (up to 60 characters) that will be reproduced on the output listing| | |COMMENT| Any comment (up to 60 characters) that will be reproduced on the output listing| | ||