MasterFrame Local Coordinates

In addition to the global coordinate system, MasterFrame also employ a local coordinate system for each physical member. The system of co-ordinates is used to define the signs of the internal forces and any loads acting normal to the member. It is sometimes known as the member system of co-ordinates. The local coordinate system is defined as follow: -

The local x-axis is along the member, and acts from node n1 towards n2.

The local y-axis is obtained by a 90-degree anti-clockwise rotation of the local x-axis.

The local z-axis acts perpendicular to the local XY plane and is found by rotating 90 degrees clockwise about the local X axis. 

Plane Frame                                                  Grillage The Relationships Between the Global and the Local Systems of Co-ordinates

Within MasterFrame, a member is defined to start at the lower numbered node at the member ends. Distance along members is therefore taken from the lower node number, unless noted otherwise, or the user selects option to defined the position relative to the end of the physical member rather than the start.

The diagram above illustrates the relationships between the Global and the Local systems of co-ordinates for plane and grillage frames.