/ANIM/SHELL/DAMA

Format

/ANIM/SHELL/DAMA/Keyword4/Keyword5

Definition

Comments

1. In case of BATOZ shell element, the value is the average value of the Gauss points in the layer.

   This applies only to failure criteria defined with Failure Models keywords, failure defined inside material laws (/MAT/LAW52 (GURSON)) is currently not available.

2. The damage value, D is the maximum value of all failure criteria of the model.

   The damage value, which is displayed, is the maximum damage value over time.

   In case of composite shell element property TYPE51, the damage value for one layer is computed as the maximum value over the all integration points of its layer.(1)

   $$D(T)={\max }_{t\le T}\left(D(t)\right)$$
3. The damage value, D is 0 ≤ D ≤ 1. The status for fracture is:

   Free, if 0 ≤ D < 1

   Failure, if D = 1

4. D is computed for every failure criteria as follows:
   • Strain based failure (/FAIL/BIQUAD)(2)
     $$D={\displaystyle \sum \frac{\text{Δ}{\epsilon }_p}{{\epsilon }_f}}$$
   • Johnson-Cook failure (/FAIL/JOHNSON) (3)
     $$D=\sum \frac{\mathrm{\text{Δ}}{\varepsilon }_p}{{\varepsilon }_f}$$
   • Tuler-Butcher failure (/FAIL/TBUTCHER) (4)
     $$D=\frac{{\underset{0}{\overset{t}{\int }}\left(\sigma -{\sigma }_r\right)}^{\lambda }dt}{K}$$
   • Wilkins failure (/FAIL/WILKINS)(5)
     $$D=\frac{{\displaystyle \int W_1{W}_{2}d{\epsilon }_p}}{D_f}$$
   • FLD failure (/FAIL/FLD) (6)
     $$D=\underset{time}{Max}\left(\frac{{\epsilon }_{major}}{{\epsilon }_{\lim }}\right)$$
   Where,

   ${\epsilon }_{\lim }$

   Major strain as limit from FLD function

   Figure 1.

   • BAO-XUE-Wierzbicki failure (/FAIL/WIERZBICKI)(7)
     $$D={\displaystyle \sum \frac{\text{Δ}{\epsilon }_p}{{\overline{\epsilon }}_f}}$$
   • Strain failure model (/FAIL/TENSSTRAIN)(8)
     $$D=\underset{\mathit{time}}{\mathit{Max}}\left(\frac{{\varepsilon }_1-{\varepsilon }_{t_1}}{{\varepsilon }_{t_2}-{\varepsilon }_{t_1}}\right)$$
   • Strain failure model (/FAIL/FABRIC)(9)
     $$D=Max\left(\frac{{\epsilon }_1-{\epsilon }_{f1}}{{\epsilon }_{r1}-{\epsilon }_{f1}},\frac{{\epsilon }_2-{\epsilon }_{f2}}{{\epsilon }_{r2}-{\epsilon }_{f2}}\right)$$
   • Energy density failure model (/FAIL/ENERGY):(10)
     $$D=\underset{\mathit{time}}{\mathit{Max}}\left(\frac{E-E_1}{E_2-E_1}\right)$$
   • Chang failure (/FAIL/CHANG)
     The maximum damage for different failure mode: (11)

     $$D=\mathit{Max}\left(e_f{}^2,e_c{}^2,e_m{}^2,e_d{}^2\right)$$
   • Hashin Composite failure (/FAIL/HASHIN)

     The maximum damage for different failure mode

     For uni-directional lamina model:(12)

     $$D=Max\left(F_1,F_2,F_3,F_4,F_5\right)$$
     For fabric lamina model:(13)

     $$D=Max\left(F_1,F_2,F_3,F_4,F_5,F_6,F_7\right)$$
   • Puck Composite failure (/FAIL/PUCK)
     The maximum damage for different failure mode:(14)

     $$D=\mathit{Max}\left(e_f(\mathit{tensile}),e_f(\mathit{compression}),e_f(\mathit{ModeA}),e_f(\mathit{ModeB}),e_f(\mathit{ModeC})\right)$$
   • Ladeveze failure (/FAIL/LAD_DAMA)
     Only used for Plyxfem in /PROP/TYPE17:(15)

     $$\dot{d}=\frac{k}{a}\left[1-\exp \left(-a\langle w\left(Y\right)-d\rangle \right)\right]$$
   • Strain Failure Model with dependence on Lode angle (/FAIL/TAB1)(16)
     $$D=\frac{\sum \mathrm{\text{Δ}}D}{D_{crit}}$$
   • NXT Failure Model (/FAIL/NXT)(17)
     $$D=\frac{{\lambda }_f}{2}$$
   • Strain based Ductile Failure Model (/FAIL/HC_DSSE)(18)
     $$D={\displaystyle \sum \frac{\text{Δ}{\overline{\epsilon }}_p}{{\overline{\epsilon }}_{HC}^{pr}\left(\eta \right)}}$$
5. This option is available only if Keyword4 = N (for each defined layer N allows to compute shell damage value within each integration point NIP of layer N). This option is only available for /PROP/TYPE51 and PCOMPP (/PROP/TYPE51 or /PROP/PCOMPP with multiple integration points through each layer).

   Nevertheless, Keyword4=ALL combined with Keyword5=ALL is allowed.