## Function

- Declare a local coordinate system for selected nodes to enter boundary conditions or produce output for reactions.

## Call

From the main menu, select **[Node/Element] tab > [Node Detail] group > [Node Local Axis]**

## Input

#### The right of Node Local Axis

Display Node Local Axis Table

### Options

**Add/Replace** : Enter or replace a local coordinate system for selected nodes

**Delete** : Enter or replace a local coordinate system for selected nodes

### Define Local Axis

**Input Method** : Select a method of specifying the node's local coordinate system.

**Angle** : Specify 3 angles of rotation to define the node's local coordinate system

**about x**

Angle of rotation about GCS X-axis

**about y**

Angle of rotation about y'-axis rotated about X-axis

**about z**

Angle of rotation about z"-axis rotated about X- and y'-axes

**3 points** : Specify 3 nodal coordinates to define the node's local coordinate system

**P _{0}**

Coordinates of the origin of the node's local coordinate system

**P _{1}**

Coordinates of an arbitrary node on the node's local x-axis

**P _{2}**

Coordinates of a node moved from P1, parallel to the node's local y-axis

**Vector** : Specify 2 vectors to define the node's local coordinate system

**V _{1}**

x-direction vector starting from the origin of the node's local coordinate system

**V _{2}**

ector starting from the origin of the node's local coordinate system to the point P2 of the 3 points method above

**Line Vector** : Specify a reference line to define the node's local coordinate system.

**Direction**

Select the component of node local axis. Selected component will be aligned into the orthogonal direction of the reference line.

**Ref****. Point**

Specify 2 nodes to define a reference line.

**P0** : Coordinates of the origin of the reference line

**P1** : 2^{nd} point of the reference line to determine the direction of reference line.

**Global Direction**

Specify a origin point and global axis to define a reference line.

**P0** : Coordinates of the origin of the reference line

**P1** : Component of the GCS axis to determine the direction of reference line.

The followings are the application functions for Node Local Axis:

"Supports"

"Point Spring Supports"

"General Spring Supports"

"Surface Spring Supports" (Convert to Point Spring)

"Specified Displacements of Supports"

Reactions > "Reaction Forces/Moments"

Influence Lines > "Reactions"

Influence Surfaces > "Reactions"

"Displacements"