ANSYS - Cable modeling

Emeflautic

Hi all,

First of all I explain my situation. I am currently doing my final thesis to get my degree in Mechanical Engineering, and the topic is Vibration Control of cable-stayed structures. I'm a begginer in ANSYS, and I have to learn it myself.

I am now trying to check how the tension in the cables influences on the natural frequency. From the math, I know that this frequency depends on the length and the tension of the cable, but I am not able to make it work in APDL. First, to make it simpler, I have modeled a symply supported cable (fixed displacements but not rotations). I am using BEAM189, (but I am not very sure that's the rigth element. My supervisor, not very trained in ANSYS, thinks it should be fine if I do it with small cross section beams).

I am doing a modal analysis of the cable, but the problem is that ANSYS is ignoring any loads on the structure. The natural frequency keeps the same no matter whether loads are aplied or not (I'm using external loads on the ends to simulate tension effects).

Any clues of what I am doing wrong, or how I should do it to change the frequency with the tension?

Any help will be really appreciated. Thank you very much.