In MMPDS-04 (and previous) the allowable for 7075-T6 bare sheet per QQ-A-250/12 is Fbru=156ksi (0.040"<t<0.125", e/D=2.0, A-basis, Table 3.7.7.0(b1)).
In MMPDS-05 (and on) the allowable is Fbru=146ksi (same parameters, Table 3.7.8.0(b1)). The table says that it was last revised in Apr 2010 per...
A colleague of mine mentioned that his company does not use a knock-down factor on the MMPDS-given allowable bearing stresses (Fbru and Fbry), and this concerned him. MMPDS is pretty clear that such knock-down factors should be used if all of the "dry-pin" conditions do not exist in your...
Hi folks; I haven't been around for a while... life just gets too busy.
Wil - this might be one for you.
The folks I represent are in the process of procuring a major piece of replacement structure for an aging airframe. The supplier wants to "butt drive" solid rivets (D-rivets) in the...
A coworker recently pointed me to the following location where all three publications authored by Bill McCombs are available:
http://www.thattechnicalbookstore.com/results.asp?o=d&au=William+F.+McCombs
The three titles are:
"Introduction to the Stress Analysis of Lightweight Aerospace...
Does anyone know the correct procedure for handling surface contact between two solids in Scenario?
I've tried creating simple models with connecting meshes using the "Surface Contact" function, and cn_mesh(1), etc. are created, but the model won't run. Model check finds no errors.
The type...
Many structural repair guidelines specify to use a 2nd oversize fastener when replacing an existing fastener in an assembly (especially when adding a doubler).
My understanding is that this is done for two primary reasons:
1. To restore the desired fastener fit.
2. To compensate for the...
