By no means I am advanced user of Grasshopper. Read few threads here which lead me to believe someone here could explain to me if I could use Grasshopper and kangaroo for below described analysis. Few threads here provided a script in which a steel wire catenary could be calculated. For case I was interested in, cable properties are expressed as seen in the screenshot. I was wondering how should I approach designing the script to obtain actual catenaries on side “1” and side “2”. They would be different I imagine based on tension values shown, and in function of the specified properties.
@martinsiegrist This was exactly the post which made me start mine. I checked file linked in there. However there, cable is fully steel and it is expressed via Youngs modulus and cross section, and material density. In my case I do not have this input as my wire is made with several materials. So I think I have to figure out how to write a script that uses bending stiffens value and weight per meter value from the list of properties I shown in the screenshot. @Joseph_Oster
In my first steps today indeed i saw that component, however as I mentioned i am only starting in this, and for sure I need to do some work on my side to even understand your explanations haha. Thank you very much for the file, I will study this and try to figure out the mechanics of those components. And try to throw few logs (or most likely twigs) under your feet again if you don’t mind
Is it possible to understand how the catenary component is calculating its output? As i mentioned in response to martin, I believe I need to express it via wire bending stiffness and weight per meter. In your script i don’t see any mechanical properties I have as input, but first I guess i need to understand them.
Thx again!
That might be an important clue that two points and cable length are all that matters?
It’s been a lifetime since I knew much about catenary curves. I worked on a line crew as a summer job in college and one day we were tasked with adding a pole at the low point of a very long span. The existing wire needed to be longer to lower it so it could be attached to the new pole. I found a formula in an engineer’s handbook that allowed me to calculate that adding only ~six inches would lower the wire by twelve feet. (I don’t remember the exact numbers.)
My estimate was accurate!! I don’t think wire properties had any bearing on the outcome.
Indeed I think this will work for at least the part of determining how much length of wire is between the points, and then I can figure out the total weight and count the reactions at the ends, to get the tension I am seeking as on my first screenshot. I think I saw somewhere in K2enginerring that a reaction value could be read from a hanging point but that would be next step. For the moment thank you for your guidance, I will surely come back with some “twigs” to throw so I can start to compile some scripts myself.
