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RE: WOOD: Lateral Design Software

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As far as I know, Lateral Pro Technology's program Q-Lat Pro is no longer
available. Part of it was incorporated through Simpson in some manner into
the Keymark software. I don't have all the information on this and if anyone
knows any different, please let us know.

I have been working with both the Woodworks Beta and the Keylat program.
Both seem to do a good job with a learning curve. Both, as was pointed out
by Mark, are limited to orthogonal walls only - at this time. Here are a few
points that I can attest to that may help you.

1. Gravity Loads: The Woodworks 2000 product will design gravity load
member. Keylat's program requires the purchase (or license) of an additional
module. What is interesting to note is that the Keylat program is actually a
part of a larger program which, I believe, was their intention behind the
Intelligent Takeoff software introduced a few years ago. To meet the demands
of the market and bring the price of the software in line, Keymark broke the
software into modules and allow the engineer, architect, or building
designer to purchase the modules that best meet their needs. I have not idea
of module cost but will be looking at each product in more detail in the
coming months.

2. Lateral Analysis: Both Woodworks and Keylat seem to be neck and neck in
this issue. I have not verified these restriction on Keylat, but the
following message occurs in their "About" file in the help pull-down menu:
A) Plate height does not vary at diaphragm level.
B)Level numbers assumed to be ascending
C) Light frame buildings assumed.
D) Orthogonal buildings with lateral force resisting elements parallel to
principle axis only.
E) Structure limited to five levels, and to fifty shear lines per level in
each direction.
F) Vertical irregularities 2 and 4 detected.
G) Plan irregularities 2 and 4 detected by flexible analysis
H) Plan irregularity 1 detected by Rigid Analysis
I) Approximate formula (Method A) used to calculate building period.

Of the above assumptions and restrictions the first one "A" worries me. How
many of us design custom homes where the plate height does not vary at
diaphragm levels. I'm not sure whether to interpret this as not allowing
various diaphragm heights to occur over the entire structure OR that each
block (between lines of shear) must have a uniform building height. As soon
as I learn more about this I'll report it to the group.

Each of the programs only accept orthogonal walls and exclude skewed walls.
This makes the programs unusable for most custom homes I work with. To be
fair, Dave Merrick has been helping to resolve this issue with our
spreadsheet. The problem appears to be applying lateral loads in both
orthogonal directions at the same time has a tendency to negate some of the
loads by rotation. Dave is much more understanding of this than I am as I
have not worked with torsion design in diaphragms before this code was
enforced. No program (ours included) seems to be perfect as yet in the
design of structures with skewed walls.

A work around for the spreadsheet is a little more straight forward. The
spreadsheet will yield more accurate results if the rigid analysis is broken
down into two separate analysis - working with the results by applying the
east-west load separately from the north-south load and then comparing the
results for an envelope solution. This is how we are approaching
modification of the spreadsheet.

3) Modeling the structure: I think that Woodworks has the advantage on this
one. I was told that Keymark's software would allow the user to open a DWG
or DXF file - but I have not been able to find this in the review copy I am
using. Nor was I able to find it in the manual. I have a feeling that this
was not instituted in this version or requires the purchase of an additional
module. Again, to be fair, I don't have any confirmation yet from Keymark on
this.
Woodworks uses a WMF (Windows Metafile Format) graphic which is scaled and
used for a background to define shearwalls. It is not an ideal solution, but
better than reconstructing a building from scratch when you know that you
are working from an existing cad (so close yet so far).

4) Output: I was not able to verify the output on Woodworks, because of my
lack of time to play with each software. What I am very concerned with is
that Keymark does not appear to provide a diaphragm deflection analysis. It
seems that most plan reviewers adamantly ask for this analysis to help
evaluate the degree of flexibility of the diaphragm. I'm not sure if
Woodworks provides this either.

There is a lack of support for any other restraint system than conventional
shearwalls or (obviously) the Simpson Strongwall. I don't know about most,
but few of the homes I do end up using only plywood shearwalls. Most need
cantilevered columns or braced frames.  Woodworks has implied that their
software will allow the user to define different types of restraints so as
to compensate for various stiffness due to different materials. It is more
of a workaround than an intentional feature. Again, this is only rumor and
needs to be confirmed by the developers.


This is about as far as I can go with opinions on either. I expect to be
spending a great deal more time with each as they are both ready for the
market. I do congratulate both commercial products for putting the cost of
the software in a very reasonable price range with good tech support and
training. If many did not know, Keymark reduced the price of the Keylat
software basic modules at $250.00 with training. You can build the system as
large as you are willing to go so that it includes all gravity load modules,
material takeoffs for bidding and much much more.
Woodworks continues to improve their software by expanding on the strength
of their software with the expansion of the lateral design per 97 UBC and an
expansion of their connections (wood connections) module to include a wider
range of connection design features. The inclusion of the latest NDS in PDF
format - which I hope is still included- was one of the strongest features.
Although their gravity load module is not dramatically changed, it did have
a very good and user friendly beam and column design module. This remains as
part of the package.

On a final note -  Keymark has responded to the confusion of issues in the
UBC. Specifically, they have addressed the 10/Lw issue by giving the user a
choice of designing per the published code AND designing in accordance with
the Blue Book Commentary (10/Lw does not need to be greater than 1.0 for
walls less than 10 feet in length).

I think that many of the unresolved issues in the code are retarding the
development of decent software tools such as these. Structural engineering
software requires compliance with the intent of the code - which often
becomes a flow chart model of how to design. If the issues remain
unresolved, the developer must make an informed guess and I'm not sure any
developer is willing to risk this decision.

Dennis S. Wish, PE