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TEnsion only member and selenderness ratio
7

TEnsion only member and selenderness ratio

TEnsion only member and selenderness ratio

(OP)
Is it possible for a tension oly member to fail because of the KL/r ratio ?

RE: TEnsion only member and selenderness ratio

I don't think there is direct relationship. But remotely remember AISC suggests that KL/r for tension member shouldn't less than 300.

RE: TEnsion only member and selenderness ratio

A tension member will not fail because of its slenderness ratio but may flap about if the tension is alternately applied and released. An example of this is a cross braced frame where each diagonal member is designed to resist tension only; a change in direction of force on the frame causes a stressed member to be suddenly released while its companion becomes stressed.

BA

RE: TEnsion only member and selenderness ratio

I don't think it's going to fail because of the L/r ratio explicitly, but it might fail because a tension member with a very high L/r ratio is going to be quite flexible and prone to vibrating and wobbling, possibly causing fatigue-related issues down the road (at least that's my understanding). I assume this is building-related, but for bridges AREMA and AASHTO both limit L/r for tension members to 200 or 240.

RE: TEnsion only member and selenderness ratio

No...a tension element cannot fail in compression
otherwise it would not be a tension element :)

RE: TEnsion only member and selenderness ratio

No. Hence, cable elements.

RE: TEnsion only member and selenderness ratio

In addition to what BA mentioned, handling is an issue with extremely slender tension members. When L/r exceeds 300 (the suggested limit retired mentioned from AISC), it's more likely that the material will be damaged as it flops around like a wet noodle on the site.

RE: TEnsion only member and selenderness ratio

No limit on KL/r for cable members. But, AISC does suggest limiting the KL/r ration for rods, and single angles and such. I haven't looked this up lately. But, if member serves me correct, it's not because of a capacity issue, but that they tend to get easily damaged / kinked. Hence the recommendation (not rule) about KL/r < 300.

Also, I believe some iterations of RISA enforce this recommendation. Though it can be changed in Tools - Preferences / Application Settings.

RE: TEnsion only member and selenderness ratio

(OP)
Thank you all, Really appreciated,
It seems that the member was failing due to the suggested value L/R exceeds 300 in STAAD and it turned to be that I can turn this check off in STAAD.

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