|But the wind
usually blows in both directions.
|When you reverse
the lateral load direction you can usually neglect the compression capacity
of the slender member ( that is really there ) because it will buckle at such
a small load and will not bend out so much that it fails.
|(We have a
special feature in the program that allows you to temporarily negate a
|You may find
that when you are looking at the capacity of the tower the shortening of the
columns due to an ultimate load may causes the diagonals to appear to fail in
compression.† If the compression force
is very small you could negate these members to get the true capacity of the
tower assuming that the braces will still be able to provide support in
tension when needed.
provided the diagonals donít fail by rotating the connections to far.† The program can give you guidance on joint
force on a model tower might be caused by placing the test load just off
center or by not constructing it perfectly straight Ė this would create the
effect of a lateral load.
|As a rule, you
need to provide some lateral load so that ModelSmart3D have something to work
|Try putting a
couple of horizontal loads (a pound or two) at the top joints of the tower
and check how sensitive your tower is to this type of force.
|You can use this
fictitious load to keep some of the diagonals in tension while you negate