Learning Forum

[Audy Maulizar]

I would love to ask for opinions of people who have experience in modelling cable-stayed bridges in ANSYS. One of the modelling aspects that stumps me is how you consider cable-sag of the stay cables caused by the cable weight. From my understanding you have several options to tackle it; 1. modelling the stay cables with multiple elements; 2. modelling the stay cables with one element while changing the elastic modulus of individual stay cables based on cable stress using methods such as Ernst's method. 

I have tried the first method, but the analysis ended up being unstable on my model. I could only make it work on very simple model and with a certain amount of pre-tension. So that leaves the second option. Finding the needed elastic modulus for the stay cables is simple enough under static condition, but I also need to conduct dynamic analyses on the model. Hence, I would love to know if there's a method to actively update the elastic modulus for stay cables  for every time step in ANSYS. Maybe by an MAPDL command or some other simpler methods?

[dlooman]

A single CABLE280 element can capture the sag of a cable and will not be unstable. 

[Audy Maulizar]

Sorry for the late response. Regarding the number of element mesh for the stay cable, is one element enough or do I have to make it into multiple elements?