The pros and cons of floating wind turbines

I am a strong supporter of renewable energy. And mostly I prefer offshore wind power.

Professor Tore Undeland, from NTNU, in 2014 was saying that, Wind power could cover Norway’s energy needs 20 times.

I believe that many other countries have similar opportunities.

Most common wind turbines use bottom-mounted towers. They are easy to install, have low maintenance cost and have a long life span. But there is a major disadvantage to them: they can be installed in relatively shallow waters.

For deep waters there is an alternative solution: floating wind turbines.

The biggest advantage I see, for owning such units, is the mobility. They can be built on land, in assembly lines, and transported to various locations. For repair they can be brought back to land.

More, floating wind turbines can be designed considering product lifecycle management. Meaning that they can be made upgradable and fully recyclable.

See also the Wikipedia page on this subject.

The main disadvantage of this solution is that is not completely understood. A lack of a histogram for a large number of such projects bring forward the “risk of the new”. Not knowing all the risks involved will make investors less interested and the market boom of the floating wind turbines is yet to happen.

Posted in offshore wind energy | Leave a comment

Connecting Solid, Plate and Beam elements

To test FEMAP’s capability to connect element types I have made the following geometry:

geometry

The pad-eye and a part of the adjacent geometry are modeled with solids. The connection between the two is made with surface to surface contact. The geometry is prolonged with surfaces and attached with surface to line contact. Finaly, the right side ends with a line. The transition from surface to line is done using a rigid element.

pad-eye  base  surface  line

The resulting meshing is presented below. To the right is displayed element cross section.

mesh  mesh with shape

Horizontal bearing force is applied to the pad-eye. The low left end and right end are fixed.

Some results are linked below:

For more details on this study please leave a comment bellow and I will answer asap.

Posted in Finite Element Analysis, working with FEMAP | Leave a comment

Using FEMAP MultiSet to simulate sliding load

sliding load staticClicking the rendering to the left will reveal an animation representing a grouping of static analysis results for a sliding load.

It is done with FEMAP’s MultiSet capability and studies the full range of motion.

When the load is shifting on the structure sometimes it is easy to estimate the worst position and run an analysis for that case. I believe a better way is to asses in small increments the full event as presented above.

Check out this discussion and more interesting subjects on FEMAP Discussion Forum.

For more details on this study please leave a comment bellow and I will answer asap.

Posted in Finite Element Analysis, working with FEMAP | Leave a comment

Buckling check using FEMAP

column checkWorking barges sometimes have columns under main deck to make local reinforcement.

I have used a theoretical model to study such a case using FEMAP. The deck is subject to uniform pressure.

bucklingTo the right of this post is displayed the first bucking mode. This corresponds to the load case and boundary conditions used. It can be concluded that the structure is safe as regarding buckling. A different loading will change the eigenvalue and location where the instability will occur firs.

For more details on this study please leave a comment bellow and I will answer asap.

Posted in Finite Element Analysis, working with FEMAP | Leave a comment