Need a book? Engineering books recommendations...

# Re: Story Drift: 1994 UBC vs. 1997 UBC

• To: seaint(--nospam--at)seaint.org
• Subject: Re: Story Drift: 1994 UBC vs. 1997 UBC
• From: Seaintonln(--nospam--at)aol.com
• Date: Thu, 12 Aug 1999 23:35:53 EDT

```Bill,

1. When I created this model in Excel I found that the units of the terms do
not balance. The first term, for example, 8fvh^3/EAb is not intended to be
converted to comparable units as Mathcad would do automatically. This is one
I received a number of responses to my previous threads as to how the units
balanced and one or two list members sent me a complete breakdown as to how
to the Algebra from 5wl^4/384EI converted to this formula above. The problem
was that Mathcad converted the units which inflated the results - the results
should be in the following units:
fv = psi
h = ft
E = psi
A = in^2
b = ft
The inclination is to convert feet to inches and, in this case, would inflate
the answer by a factor of 12.

The next issues is the Load per nail that you use. This should be the actual
nail load based on the actual shear in the panel rather than the allowable
capacity of the plywood - therefore, your load per nail should be somewhat
less. This is moot since you might be assuming that your demand is equal to

I might be wrong on this one, but the t for a non-structural grade 3/8" thk
panel should be 0.298" rather than 0.373. I did not take the time to check my
spreadsheet, but this is what I get off the lookup tables. Again, I might be
the one who is wrong here.

The nail elongation term is another one where the units are not suppose to
balance. the results are to be in inch-feet but assumed inches. Again, this
is an emperical formula and nobody to date has been able to tell me why
constants of 1/feet was not used to clarify this. This might yield an error