Search found 1275 matches

by HarryvL
Mon Mar 18, 2024 1:06 am
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

I do not really understand the triaxiality concept. When doing a hand calculation (with stress/strain tensors at yellow "X") I get a very low triaxiality, as to expect, nearly pure shear. PEEQ is 5%, analog to IdeaStatica the plastic limit is reached. In the end I get a epsilon_cr of 32%....
by HarryvL
Sun Mar 17, 2024 7:35 pm
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

I do not really understand the triaxiality concept. When doing a hand calculation (with stress/strain tensors at yellow "X") I get a very low triaxiality, as to expect, nearly pure shear. PEEQ is 5%, analog to IdeaStatica the plastic limit is reached. In the end I get a epsilon_cr of 32%....
by HarryvL
Fri Mar 15, 2024 8:33 am
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

Latest update includes setting a target load factor. The analysis will halt and display the load-displacement curve at the specified target load factor (0.55 in the example below) or after completing the specified number of load steps, whichever comes first. To get the collapse load, just put a lar...
by HarryvL
Thu Mar 14, 2024 5:05 pm
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

thschrader wrote: Thu Mar 14, 2024 4:31 pm BTW, what does the CSR value mean?
CSR = Critical Strain Ratio = PEEQ / critical strain

CSR < 1.0 OK. CSR > 1.0 plastic rupture.
by HarryvL
Thu Mar 14, 2024 2:52 pm
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

I would use this workflow: Run a linear FEM analysis, check if sigma-vM exceeds the limit (in this case yes, above the stiffeners) Open fcVM-wb, use a load factor of 1,1 (for material safety) an plot the capacity curve. Check if the critical strain ratio is below 1. If so, check the peeq, in this c...
by HarryvL
Thu Mar 14, 2024 1:22 pm
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

In the next update I will report the maximum PEEQ and Critical Strain Ration (@ the integration points) below the progress bar. I have updated the panel and plots to choose between CSR and PEEQ output =============================================== Updated fcVM panel and plot.png ==================...
by HarryvL
Wed Mar 13, 2024 5:18 pm
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

In the next update I will report the maximum PEEQ and Critical Strain Ration (@ the integration points) below the progress bar.
by HarryvL
Wed Mar 13, 2024 5:10 pm
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

I would use this workflow: Run a linear FEM analysis, check if sigma-vM exceeds the limit (in this case yes, above the stiffeners) Open fcVM-wb, use a load factor of 1,1 (for material safety) an plot the capacity curve. Check if the critical strain ratio is below 1. If so, check the peeq, in this c...
by HarryvL
Wed Mar 13, 2024 3:50 pm
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

What gives me a headache is the wide range of alpha-values in table 4, used for EQ.4. Yes and these values are very large. Take alpha=3.0, for example. The formula would predict a critical strain of 3.0*exp(-1.5*1/3)=1.82 for a uniaxial tensile test (where triaxiality T=1/3). In fcVM I start from t...
by HarryvL
Wed Mar 13, 2024 1:45 pm
Forum: FEM
Topic: fcVM workbench
Replies: 80
Views: 5414

Re: fcVM workbench

... and (for example) to judge residual deformation after a loading/unloading cycle, set Output Options to Total Displacements, the Target LF to the desired value (0.55 here) and after achieving this value, set the Target Load Factor in the Matplotlib screen to 0.0. The Load-Displacement graph and R...