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Re: Crane Runway Bracing Vibration[Subject Prev][Subject Next][Thread Prev][Thread Next]
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- Subject: Re: Crane Runway Bracing Vibration
- From: Himanshu Goyal <anshuagoel(--nospam--at)gmail.com>
- Date: Fri, 6 Jun 2014 18:14:50 -0500
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Isn't it the buckling mode vibration of the angle bracing, if I understood correctly ? In my view, when crane starts and stops - it transmit a horizontal acceleration or deceleration - longitudinal forces - which come as axial forces in the bracing. I think horizontal strut alone would solve the problem. or you can add vertical brace in another brace - also, you can try to soften the acceleration at starting and stopping by restricting maximum speed ? It would seem a serious problem to me, if not worked upon quickly - because if there is some residual deformation in angle and it again tries to buckle - it can really buckle. On Fri, Jun 6, 2014 at 6:46 AM, Gary L. Hodgson and Assoc. < design(--nospam--at)hodgsoneng.ca> wrote: > Fellow listers, > I have a problem that I have never run into before. I designed a free > standing crane rwy for a 30 ton EOT crane. The column centres are approx > 28.5 ft, with only 5 bays and the columns are braced about the weak axis > by X-bracing in one bay (at centre of rwy, both sides) consisting of > L6x4x5/16 with the long leg horizontal, connected by a bolt where the 2 > angles cross. When the crane starts up and starts travelling down-aisle, > the bracing vibrates to the annoyance of the customer and his workers. The > vibration is out of the plane of the X-bracing. This does not happen if > the crane starts elsewhere, and just passes over the braced bay. > First, I had the existing bracing pulled tighter - did'n't work. Next, > I added reinforcing angles i.e, boxed the angles but that did not solve > the problem. My next attempt will be to add a horiz strut between the > columns and then connect that to the X-bracing with a short length of angle > to the centre of the X-bracing so it will prevent or decrease the amount > of out-of -plane motion. > Can any of the members suggest another solution? > Gary ------------------------------------------------------------------------- Post your message to the list by sending it to: SEAINT-SEAOSC(--nospam--at)mail-list.com. The email messages sent to the list will be saved in an archive on the World Wide Web. These archives are located at: http://archive.mail-list.com/SEAINT-SEAOSC To contact the list owner, send your message to: SEAINT-SEAOSC-list-owner(--nospam--at)mail-list.com. Sponsored By: Pacific Structural & Forensic Engineers Group, Inc. (PSFEG) To unsubscribe, switch to/from digest, get on/off vacation, or change your email address, click here. <http://cgi.mail-list.com/u?ln=seaint-seaosc&nm=seaintma%40euken.net>
- Crane Runway Bracing Vibration
- From: Gary L. Hodgson and Assoc.
- Crane Runway Bracing Vibration
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