Lachlan1357
Student
- Feb 24, 2022
- 1
Hi there,
I am wondering if anyone could help me with a bit of software called SESAM. For my dissertation I am making a wave energy converter array and for this I am having to design a WEC in genie and then import it into hydroD and conduct multi body analysis. Now, I know how to do multi body analysis and understand the that there is a stiffness matrices that need to be filled, then the analysis can be run and the coupled motion of the my WEC's can be analysed. What I am struggling with is, due to the fact that my WEC is an attenuator design, there are two bodies that will oscillate in the pitch degree of freedom and any other coupled degrees of freedom should be constrained. From here I assumed that you can input an infinite value into the corresponding degrees of freedom that are in the matrix. Through further research nothing is really infinite, therefore, I tried putting in a large value with a magnitude x10^100 to try and simulate this hinge connecting the two bodies. This caused issues with the software and I ended up getting error messages.
My first question is there any way I can trouble shoot this issue of the error message when inputting very large values into the stiffness/damping matrix or is there another method that can be used to constrain the desired degrees of freedom so that I could simulate a PTO hinge?
My second question is to do with the software in the SESAM package called genie, in this you model your deign. When I was playing around with it and came across hinges. These hinges can be placed on beams and they constrain selected degrees of freedom. Therefore, what I am asking is that if I attached one beam for each body of the WEC and put a hinge in-between the two beams, would this simulate the PTO hinge. Could this method be able to replace the multi body matrices method?
Cheers
Lachlan
I am wondering if anyone could help me with a bit of software called SESAM. For my dissertation I am making a wave energy converter array and for this I am having to design a WEC in genie and then import it into hydroD and conduct multi body analysis. Now, I know how to do multi body analysis and understand the that there is a stiffness matrices that need to be filled, then the analysis can be run and the coupled motion of the my WEC's can be analysed. What I am struggling with is, due to the fact that my WEC is an attenuator design, there are two bodies that will oscillate in the pitch degree of freedom and any other coupled degrees of freedom should be constrained. From here I assumed that you can input an infinite value into the corresponding degrees of freedom that are in the matrix. Through further research nothing is really infinite, therefore, I tried putting in a large value with a magnitude x10^100 to try and simulate this hinge connecting the two bodies. This caused issues with the software and I ended up getting error messages.
My first question is there any way I can trouble shoot this issue of the error message when inputting very large values into the stiffness/damping matrix or is there another method that can be used to constrain the desired degrees of freedom so that I could simulate a PTO hinge?
My second question is to do with the software in the SESAM package called genie, in this you model your deign. When I was playing around with it and came across hinges. These hinges can be placed on beams and they constrain selected degrees of freedom. Therefore, what I am asking is that if I attached one beam for each body of the WEC and put a hinge in-between the two beams, would this simulate the PTO hinge. Could this method be able to replace the multi body matrices method?
Cheers
Lachlan
