A manual for - LARSA, Inc.

LARSA 4D Introductory Training Manual
Joint Reaction Envelope
The minimum (or most negative) Z reaction on the left joint is due to the wind load. The negative Z
reaction there on joint 1 indicates an uplifing force.
Shading in the Force Z column is a reminder that envelopes have been turned on.
Close the spreadsheet.
Member Stresses
To see member stresses, use Results → Spreadsheets → Member → Stresses .
Both result cases are still active. Let’s have just Dead result case be active. Click the Dead result
case to select it and unselect other result cases.
The stresses spreadsheet shows the stress at stations along each member. The number of stations can
be set by the user. Let’s use five segments (six stations).
Go to Results → Results Display Settings .
In the top-right box set Segments to 5. (These options are also used for graphical results
diagrams.)
Click OK .
Set member results segments to 5
In the spreadsheet, for each member there are stations 0 through 5. 0 is the start of the member. 5,
since we set 5 segments, is the end of the member.
The normal stresses are given at what are called “stress recovery points” for the member’s cross-section
definition. The stress recovery points for an I-shape are at the four extreme corners. You can use the
sections spreadsheet to determine the local y and z coordinates of each of the stress recovery points
on the cross-section. Normal stress is the sum of extensional stresses caused by the axial force and
bending moments at the station.
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