Dear STKO team:
I have built a simple joint model containing pinching4 material, I did hysteretic analysis using dispBeamColumn element and forceBeamColumn element respectively. The other parameters are same, but the hysteresis curves and fiber strain are very different. What is the reason for the difference? I am curious which result is correct.
Model is in the attachment. Looking forward to your reply. Thanks in advance.
Best wishes
Significant differences in results between dispBeamColumn and forceBeamColumn element
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Edmond2000
- Posts: 12
- Joined: Sat Jan 27, 2024 12:40 pm
Significant differences in results between dispBeamColumn and forceBeamColumn element
- Attachments
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- model.zip
- (164.12 KiB) Downloaded 141 times
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- bottom strain using force elem.jpg (427.29 KiB) Viewed 949 times
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- bottom strain using dip elem.jpg (447.32 KiB) Viewed 949 times
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- top strain using force ele.jpg (416.71 KiB) Viewed 949 times
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- top strain using disp ele.jpg (452.84 KiB) Viewed 949 times
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- hyst curve using force elem.jpg (93.22 KiB) Viewed 949 times
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- hyst curve using disp elem.jpg (90.68 KiB) Viewed 949 times
Re: Significant differences in results between dispBeamColumn and forceBeamColumn element
Short answer:
Force-based element is more accurate. Disp-based -> you need more elements per structural member.
Long answer:
Since you are using pinching 4 with softening, you have to pay attention to mesh-objectivity with respect to the amount of dissipated energy.
Check this webinar:
https://asdea.eu/software/university-courses/
OpenSees Support Group - tips and tricks in frame modelling
Force-based element is more accurate. Disp-based -> you need more elements per structural member.
Long answer:
Since you are using pinching 4 with softening, you have to pay attention to mesh-objectivity with respect to the amount of dissipated energy.
Check this webinar:
https://asdea.eu/software/university-courses/
OpenSees Support Group - tips and tricks in frame modelling