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TR.32.1 Joint Load Specification

This set of commands may be used to specify joint loads on the structure. For dynamic mass modeling see TR.32.10 Dynamic Loading Specification and G.17.3 Dynamic Analysis.

General Format

JOINT LOAD
joint-list (inclined-spec) *{ FX f8 | FY f9 | FZ f10 | MX f11 | MY f12 | MZ f13 }

Where: 

inclined-spec = INCLINED { f1 f2 f3 | REF f4 f5 f6 | REFJT f7 }

Use the optional inclined-spec to specify a joint load in a inclined load axis. See Inclined Load Axis System below for details.

ParameterDescription
f1, f2, f3 x, y, z relative distances from the joint in the global directions to the reference point
f4, f5, f6 x, y, z global coordinates of an arbitrary reference point
f7 a joint number whose x, y, z global coordinates are the reference point
f8, f9, f10 force values in the corresponding global direction (even at inclined support joints).
f11, f12, f13 moment values in the corresponding global direction.

Example

UNIT FEET KIP
*…
JOINT LOAD
3  TO  7  9  11  FY  -17.2  MZ  180.0
5  8  FX  15.1
UNIT INCH KIP
12  MX  180.0  FZ  6.3

Notes

  1. Joint numbers may be repeated where loads are meant to be additive in the joint.
  2. A UNIT command may be on lines in between joint-list lines.
  3. If moments are for dynamic mass, then the units are assumed to be force-length2.

Inclined Load Axis System

If the joint loading is specified using the option INCLINED, then the axes in which the direct forces (and about which for moment forces) are applied are realigned from the global directions of X, Y, and Z to the directions x', y', and z' as shown below.

The reference point –whether it is specified using absolute coordinates, relative distances, or a reference joint– defines the direction of the x' axes from the loaded node to the reference point. The direction of the Y' axes is then defined as the direction perpendicular to x' that lies in the plane of X' and Y. In the special case of when X' is in the direction of Y, Y' is taken to be the direction of Z. The direction of Z' is then defined as the direction perpendicular to the plane X' and Y' and follows the right-hand rule as for all other axes systems used in STAAD.Pro.

Note: All joint loads in a joint list must act along the same reference system. Loads at different inclined reference systems must be specified at each joint separately. Thus, after resolving inclined loads along three global directions at each joint, they must be same for all joints included in the joint list.

Example

JOINT LOAD
4 INCLINED 1.0 -1.0 0.0 FX 10

JOINT LOAD
3 INCLINED REFJT 7 FZ -30
Parent topic: TR.32 Loading Specifications
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