@TheFeds Yes that Australian example is exactly it. That's where I am. Company doesn't keep our policy where client facing people can get it. Won't go out by mistake. Certificate of currency is accepted by 95%. Only occasional troublemakers want more and they simply can't have it. Nothing we can...
I wouldn't at least without double checking. Might be regional but I've been warned our policy is void if sent out. One of the policy terms. Maybe also a problem with clauses requiring you to minimise damages. Giving out insurance terms lets clients tailor claims to get max out of insurer.
@human909 Ok would have to see details. Sounds like lots of variables interacting. First two with hogging but full fixity show 9200 effective with bearings is quite different from 9200 idealised. Same for last two. Is three stiffeners giving warping restraint or changing bending moments? Any...
@human909 I don't understand your results. Not clear what axis is being fixed and which give hogging moment. All cases? Just first two? What is pinned @ centre in the last one?
Sounds like you are comparing F restraints to P restraints. Only significant in AS4100 for short beams not long ones.
@Tomfh Thanks for link to engineers vs sheep. Almost same analysis including beam size. I shouldn't have bothered.
I still think it's misworded in AS4100. Seems that people on or around code committee didn't think it worked with moment reversal when written but no question it is correct for...
@Tomfh @human909 Thanks for updated Portal Frame Design content. I thought codes changes weren't enough to justify new copy. Maybe will have to or maybe not. See below.
@human909 Reason for 400kNm hogging moments at supports is because I applied moment there instead of fixed supports to get...
@human909 Yes, 12m IPE600. But now switching to British UB 610x229x125 so can compare with similar British LTB software. You doing bulk solids work to get 900 tonnes?
@Tomfh See image below. Used SCI Mcr online analysis tool because easier to do multiple cases. But then checked with LTBeamN...
Thought of another reason portal frames not having the problem. Fly brace at end of haunch gives F restraint.
Here's what Design of Portal Frame Buildings book says. Bradford coauthor and also coauthor of AS4100 section 5 commentary. People designing how this book says will avoid problem...
@human909 Could be lots of reasons. Usual things like unrealistic design loads, load factors, safety factors. Governed by deflection or other part of rafter length. Could be because that Portal Frame Design book says ignore purlin restraint in reverse curvature and take full length between fly...
Yes I remember now. AS4100 civers but unconservative. L restraints work how it says for single curvature but also used for reverse curvature. For case in image with IPE600 section it's almost 50% overestimate of critical buckling moment.
@Tomfh Like in image? I ran one case in LTbeam. Critical moment was >50% higher for 4m FL beam than 12m beam with continuous top restraint. If not what you mean how would you use AS4100 for this beam?
Are you saying you take segment length as length in hogging moment? I don't think that's right. Maybe close enough since will follow trend but not sure good enough for critical designs.
@Tomfh Continuous restraint of one flange but with compression for part of opposite flange. AS4100 calls it either full lateral restraint or unrestrained. Compare with US and British/Europe literature which give design rules. Personallt I think AS4100 assumed simply supported so unconservative...
Not sure if Tekla is considering top flange restraint. Euro code reference should be Appendix BB and not 6.3.2.1? Regardless I reckon result would be wrong for case with -1.0kNm end moments. You have made situation very slightly different to simply supported. Might get passing result (not sure)...
"I'm not sure quite what you are saying here but AS4100 certainly does reject restraints continuous or otherwise of the top flange if they are considered suitable restraints to prevent LTB. To quote 5.5.1 "The critical flange at any cross-section is the flange which in the absence of any...
