Transforming from Global to Local - CAESAR II - Help

CAESAR II Users Guide (2019 Service Pack 1)

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English
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CAESAR II
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CAESAR II Version
11.0 (2019)

Converting or transforming values from the CAESAR II Global Coordinate System to a local coordinate system involves applying a number of rotation matrices to the global values. Matrix mathematics is not a trivial task, and you must exercise the utmost care to arrive at the correct result. To complete this task, visit the CAESAR II Downloads page at https://smartsupport.intergraph.com/app/downloads and click CAESAR II "Global to Local" to download the GlbtoLocal utility, glbtoLoca. zip. For more information, see the July 2001 issue of our Mechanical Engineering News. For an example on how to use the GlbtoLocal utility using the nozzle at node 50 see below.

The element 40-50 is defined with the delta coordinates of:

DX = 3 ft. (6.426 in)

DY = -3 ft. (6.426 in)

DZ = 0.0

The global restraint forces at node 50, in global coordinates, for the operating case are:

FX = 323 MX = -953

FY = 4 MY = -9

FZ = -271 MZ = -548

Using this data as input to GlbtoLocal, the utility yields the forces on the restraint in the element’s local coordinate system. This is shown in Figure 21 below.

Example Global to Local Transformation

Compare the set of values labeled Rotated Displacements / Load Vector with the Local Element Force / Moment report, as shown above. A change in sign is necessary because the Restraint report shows loads acting on the restraint, while the Element report shows loads acting on the element.