Moments are the product of force and distance relative to a point and induce rotational force. Moments can be applied to nodes or at a point along with a member. In both cases, the location, magnitude, and sign direction need to be specified. Moments that are applied at an angle to the node or member can be specified by providing the X, Y, Z components of the moment.
Moments follow the sign convention of the “right-hand” grip rule. The sign convention is dependent on which axis the moment is applied to:
- Positive (+): Counter-Clockwise
- Negative (-): Clockwise
Moments applied to Nodes
To apply a point load on a node, simply specify values for:
- Node ID – The node where the moment is applied.
- Magnitude about X – Moment about the global X-axis.
- Magnitude about Y – Moment about the global Y-axis.
- Magnitude about Z – Moment about the global Z-axis.
- Load Group – Loads can be grouped with Load Group numbers. The Load Groups can then be multiplied by a factor in the ‘Load Combos’ menu. Optional.
Here is an example of a 20kNm moment being applied to an end node looks like:
Moments applied to Members
To apply a point load on a member, simply specify values for:
- Member ID – The member where the point load is applied.
- Position Along Member – The % position (from node A t B) along the member where the force is to be applied.
- Magnitude about X – The magnitude of the force in the global X-direction. Use negatives to specify the negative X direction.
- Magnitude about Y – The magnitude of the force in the global Y-direction. Use negatives to specify the negative Y direction.
- Magnitude about Z – The magnitude of the force in the global Z-direction. Use negatives to specify the negative Z direction.
- Load Group – Loads can be grouped with Load Group numbers. The Load Groups can then be multiplied by a factor in the ‘Load Combos’ menu. Optional.
Here is an example of a 20kNm moment being applied to the middle of a member looks like: