# /SKEW/MOV

Block Format Keyword Describes a moving local coordinate system.

## Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/SKEW/MOV/skew_ID
skew_title
node_ID1 node_ID2 node_ID3 Dir

## Definitions

Field Contents SI Unit Example
skew_ID Skew identifier

(Integer, maximum 10 digits)

skew_title Skew title

(Character, maximum 100 characters)

node_ID1 Node identifier N1

(Integer)

node_ID2 Node identifier N2

(Integer)

node_ID3 Node identifier N3

(Integer)

Dir
X, Y, or Z
Define the local direction of N1 N2 axis

Default = X (Text)

1. Moving skew defines a local coordinate system, defined by three nodes. At each time, the actual orientation of the skew is recalculated according to the actual position of these nodes.
2. For moving skews, the skew system is moving and is defined by node identifiers node_ID1, node_ID2 and node_ID3.
The axis definition depends on the input for Dir.
• When Dir=X

node_ID1 amd node_ID2 define $X\text{'}$

node_ID1 and node_ID3 define $Y"$
• $Z\text{'}=X\text{'}\Lambda Y"$
• $Y\text{'}={Z}^{\prime }\Lambda {X}^{\prime }$
• When Dir=Y

node_ID1 and node_ID2 define $Y\text{'}$

node_ID1 and node_ID3 define $Z"$
• $X\text{'}={Z}^{″}\Lambda {Y}^{\prime }$
• $Z\text{'}={X}^{\prime }\Lambda {Y}^{\prime }$
• Case Dir=Z

node_ID1 and node_ID2 define $Z\text{'}$

node_ID1 and node_ID3 define $X"$
• ${Y}^{\prime }={X}^{″}\Lambda {Z}^{\prime }$
• ${X}^{\prime }={Y}^{\prime }\Lambda {Z}^{\prime }$
The skew is defined by $X\text{'}$ , $Y\text{'}$ and $Z\text{'}$
3. When defining some conditions with respect to the skew in cylindrical coordinate system, the axis of the cylindrical coordinate system is assumed to pass through node N1.