CAEPIPE can identify discontinuity in your pipe connections.
This feature can come in handy when modeling complex or involved piping
layouts. The command, "Check connections," is available under
the menu Misc in the Layout window.
Use this command to check for missing connections between pipes. By studying
the following two figures, can you identify what is wrong with the modeling?
CAEPIPE can.
By studying the Layout window shown below, you will notice that even though
node 50 seems to be on the header (node 10 to node 25), it actually is
not. Node 10 connects directly to node 20 which connects to node 25. The
loop begins from node 20 and goes up to node50. But 50 is not defined
on the header! So, there is no closure for the loop with the header.
The solution, of course, is to add 50 between 10 and 20 while defining
the header.
In addition to the listing of individual load case results
available under "Support Loads," Caepipe results also provide
a support by support summary of load combinations under "Support
Load Summary" (see table below). This summary includes algebraic
combinations of the individual loads which provide design basis loads
for various applicable load combinations or conditions. The various combinations
are useful when designing to criteria which are different for different
loading conditions.
A couple of points regarding the summary follow.
Note that for unsigned cases, combinations with other loads include both
a positive and negative case combination, e.g., Operating1 + Seismic and
Operating1 - Seismic. What this means is that a seismic load is assumed
to act in both the positive and the negative directions. When you examine
these two rows in the table below, you will find that the largest positive
FY results from Operating1 + Seismic (1572 lb) while the largest negative
MX results from Operating 1 - Seismic (-6994 ft-lb.). This suggests that
both cases (Operating1 + Seismic and Operating1 - Seismic) need to be
considered.
Maximum and Minimum loads: It is possible for any load component to have
the same sign under both the maximum and minimum loads, a potentially
confusing circumstance. For example, MX in the table below includes a
minimum load of -6,994 ft-lb. and a maximum load of -291 ft-lb. These
load totals result because they are determined algebraically, not absolutely,
and mean that under all conditions considered the support will see only
negative loading. In this case, the support should be designed to handle
a range of loading from 291 to 6994 ft-lb. in the negative X direction.
To see summaries for other supports, either click on the Other Supports
button on the toolbar or click on the white arrows next to the button.
This article was contributed by Robert
E. Serb, P.E., of PPEA Associates.
You probably already know this. If you don't, you need
to. This can make your job much easier.
Using this command, you can change Material/Section/Load/Friction Coefficient
in one operation.
In Layout, use menu Edit > Change command for block operations such
as changing a friction coefficient for all guides and limit stops within
a range of rows, or changing the material, section or load for a range
of rows. You are asked for the range when you select this command from
the Edit menu. Be sure to enter row numbers (not node numbers). If you
want to change till the end of the model and you do not know the exact
row #, simply enter 9999 (to designate end of model).
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