bucking of rivets in machined parts

huangyhg

bucking of rivets in machined parts
hello,
can anyone offer some insight into thier company policy regarding bucking rivets thru machined parts, in an airframe? is it prohibited for concern of creating damage (micro-cracks) to the machinings ?
appreciate any thoughts on this.
regards,
gerry y
eng-tips forums is member supported.
hi gerryy!
solid rivets require high forces for installation which can, in some cases, damage rigid structure such as machined flanges. this is especially true for the vibration driving of titanium, a-286 and monel solid rivets. the vibration driving of aluminum rivets require only moderate forces, but just to be safe, i usually prohibit vibration driving of all rivets in machined flanges and composites.
hope this helps.
chuck
what chuck just wrote is very true. in my designs i always specify hi-lok type close tolerance bolts and collars when fastening machined parts in assemblies. close tolerance bolts of this type are usually stronger than solid rivets.
dean
bucking solid rivets causes the rivet to swell inside the hole being riveted which in turn loads the hole in hoop tension.  you need to be sure that there is a minimum thickness of material around the hole (minimum 2*rivet diameter from hole center to edge of part)so the part doesn't crack.  if the hole location will be highly stressed, the pre-load needs to be factored into all calculations.
kesac (visitor)22 aug 02 19:12
boeing has been driving rivets into castings and forgings for 40 yr. that i know of.  mcdonnell used to prohibit vibratory riveting in titanium parts, on f15, and specified squeezed rivets.  cold worked, and interference fit hilocks/hlts give some substantial hooping and pre- loads also, which is not always a bad thing.