Search found 61 matches

by Dhaneesh.Machavarapu
Wed Jul 15, 2020 12:39 pm
Forum: General
Topic: NREL 5MW monopile OWT modelling details
Replies: 5
Views: 213

Re: NREL 5MW monopile OWT modelling details

Sir,

My question was whether my understanding regarding the F*r|platform and Fr|platform forces when seismic loading is also acting on a monopile OWT is correct? And Can we get mass and stiffness matrices as a direct output from mbc?

Thank you.
by Dhaneesh.Machavarapu
Wed Jul 15, 2020 11:56 am
Forum: Structural Analysis
Topic: Simulating OC3 phase II coupled springs in FAST v7
Replies: 14
Views: 3086

Re: Simulating OC3 phase II coupled springs in FAST v7

Sir, Thank you for clearing my doubts about my sample results and information regarding the Campbell diagram. But one thing which concerns me is my tower base shear response. From my sample results, for the TwrBsFxt(Tower base shear) response when the ground motion of 0.64g strikes after 400 seconds...
by Dhaneesh.Machavarapu
Wed Jul 15, 2020 8:19 am
Forum: General
Topic: NREL 5MW monopile OWT modelling details
Replies: 5
Views: 213

Re: NREL 5MW monopile OWT modelling details

Sir, Sorry for my late reply. Yes, I do have FAST input files. Currently for my Mtech thesis, I was working on Platform model 2 i.e, Bottom fixed offshore wind turbine with foundation modeled as coupled springs. I have some doubts and I am asking it here for my clarification. Please correct me if my...
by Dhaneesh.Machavarapu
Mon Jul 13, 2020 1:26 pm
Forum: Structural Analysis
Topic: Simulating OC3 phase II coupled springs in FAST v7
Replies: 14
Views: 3086

Re: Simulating OC3 phase II coupled springs in FAST v7

Sir, 1. Regarding tower response when an earthquake of 0.64g strikes the OWT after 400 seconds, both the TTDspFA and TwrBsMyt have shown a similar graph but the TwrBsFxt graph was different. Can you think of any reason for this? And I have done 44 such simulations for earthquake ground motions rangi...
by Dhaneesh.Machavarapu
Sun Jul 12, 2020 5:38 am
Forum: Structural Analysis
Topic: Simulating OC3 phase II coupled springs in FAST v7
Replies: 14
Views: 3086

Re: Simulating OC3 phase II coupled springs in FAST v7

Sir, 1. I have enabled the echo option in the fastv7 input file for debugging errors. In the echo file I was missing the "CURRENT" section at the bottom of the FAST v7 platform input file, i.e.: Was it meant there was something wrong with my input files? ---------------------- CURRENT ----...
by Dhaneesh.Machavarapu
Wed Jul 08, 2020 12:55 pm
Forum: General
Topic: NREL 5MW monopile OWT modelling details
Replies: 5
Views: 213

NREL 5MW monopile OWT modelling details

Sir,

In Fastv7 for the platform model 2 i.e, for the monopile offshore wind turbine. what were the mesh sizes, type of element, and total no.of nodes used for the turbine, tower, and monopile assembly.

Thank you.
by Dhaneesh.Machavarapu
Fri Jul 03, 2020 12:45 pm
Forum: Structural Analysis
Topic: Simulating OC3 phase II coupled springs in FAST v7
Replies: 14
Views: 3086

Re: Simulating OC3 phase II coupled springs in FAST v7

Sir, I was getting an error while conducting linearization analysis for a bottom fixed offshore wind turbine with foundation modeled as a coupled spring model in fastv7. The error message I got was "error occurred while reading CurrMod". I also tried conducting linearization analysis with ...
by Dhaneesh.Machavarapu
Sat Jun 27, 2020 12:31 pm
Forum: Structural Analysis
Topic: Deflection of ElastoDyn
Replies: 15
Views: 930

Re: Deflection of ElastoDyn

Sir, I have seen some of the topics in this forum regarding the damage of tower and monopile. For the monopile supported offshore wind turbine with foundation modeled using coupled springs under the action of combined seismic, wind & wave, does the output parameter TwrBsMyt represents the moment...
by Dhaneesh.Machavarapu
Fri Jun 26, 2020 12:28 pm
Forum: Structural Analysis
Topic: Deflection of ElastoDyn
Replies: 15
Views: 930

Re: Deflection of ElastoDyn

Sir, I have used the coupled spring model for platform model 2 in FASTv7 and conducted a nonlinear dynamic analysis for NREL 5MW offshore turbine under the action of seismic, wind& wave. I conducted a fragility analysis and calculated the fragility functions for a displacement damage state for t...
by Dhaneesh.Machavarapu
Tue Jun 23, 2020 1:57 pm
Forum: General
Topic: Current and Wave simulation
Replies: 9
Views: 2325

Re: Current and Wave simulation

Sir, I have simulated wave loading by modeling a sea state with significant wave height 5m and peak spectral period of 12.4 sec using the JONSWAP spectrum for bottom fixed monopile. And I observed that inertia force was more than drag force. But my structure is small compared to the wave. 1. if so F...
by Dhaneesh.Machavarapu
Mon Jun 22, 2020 1:35 pm
Forum: Structural Analysis
Topic: Simulating OC3 phase II coupled springs in FAST v7
Replies: 14
Views: 3086

Re: Simulating OC3 phase II coupled springs in FAST v7

Sir,

Yes. I was missing the Current section in the echo file with an error displaying "error occurred while reading CurrMod" while doing linearization analysis for the fixed bottom offshore case with a coupled spring model.Can I get some help regarding this?

Thank you.
by Dhaneesh.Machavarapu
Mon Jun 22, 2020 6:06 am
Forum: Computer-Aided Engineering Software Tools
Topic: Instructions for Compiling FAST
Replies: 250
Views: 131403

Re: Instructions for Compiling FAST

Sir, I have read your post on Nov 4, 2010, and got cleared my doubt which I mentioned in my earlier post. So I tried doing linearization analysis to find the highest natural frequency for setting proper time step. But I have a problem while doing linearization analysis which I have mentioned in othe...
by Dhaneesh.Machavarapu
Sun Jun 21, 2020 12:50 pm
Forum: Structural Analysis
Topic: Simulating OC3 phase II coupled springs in FAST v7
Replies: 14
Views: 3086

Re: Simulating OC3 phase II coupled springs in FAST v7

Sir, I was trying to conduct a linearization analysis to get natural frequencies for platform model 2(i.e, Fixed bottom offshore) coupled spring model in seismic. But while performing analysis I was getting an error message like an error occurred while trying to read CurrMod. This was the echo file ...
by Dhaneesh.Machavarapu
Sun Jun 21, 2020 12:33 am
Forum: General
Topic: Static Pushover Analysis
Replies: 1
Views: 147

Static Pushover Analysis

Sir,

In FAST, Is it possible to conduct Static pushover analysis to check the nonlinear behavior of monopile supported offshore wind turbine? I want to check the linear & nonlinear deformation at the tower top.

Thank you.
by Dhaneesh.Machavarapu
Sat Jun 20, 2020 9:58 am
Forum: Computer-Aided Engineering Software Tools
Topic: Instructions for Compiling FAST
Replies: 250
Views: 131403

Re: Instructions for Compiling FAST

Sir, While running Simulations using a coupled spring model for combined seismic, wind, and wave loading, I was getting an error message as below. I tried reducing the time step in the input.fst file and increasing damping for the tower in tower monopile CS.dat file. Even though the same error was d...

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