Deflection allowance for steel cable stays

[dbest69er]

Hi guys,

I'm currently working on the design of a conveyor salt stacker which includes four 45mm diameter rods as stay supports. I was trying to find some guidelines for the maximum allowable deflection of a cable stay in a structure like this (I guess it could be treated as a bridge). I'm currently in Australia and have used the AS4100 steel code to check the deflection of the ordinary steel members but I can't seem to find any standard or source which gives a clearly defined limit for maximum deflection of cable stays (maybe something like Δ/l<1/250). I didn't even find anything in the wind code.

Can anyone recommend anything???

 

[dhengr]

Dbest69er:
When you say “four 45mm diameter rods as stay supports,” I assume you mean the sloped tension ties which tie the tip, and/or mid point, of the boom back to the main structure and mast? I would be surprised if there was a deflection (sag) criteria for these. The DL of the boom and conveyor will keep a fairly high tension on these tie rods. Obviously, you do not want them to go slack. They will just assume some catenary shape as a function of their dia., length, slope, tension and material properties, etc. That’s just the nature of the problem. And, who cares as long as they keep the boom tip or mid point within tolerable deflection limits, and they are reasonably stressed themselves. I imagine you could worry about these ties vibrating in a wind or some such. Probably the most important consideration on these tie rods (stays) is that their end terminations be pinned, so they do not induce any secondary bending in the tie rods. That is, the tie rods act only as tension members in a catenary fashion. Then, you also need some tensioning (adjusting) means (turnbuckles?) which allow you to make pair of tie rods act together properly.