CHBDYP

Geometric Surface Element Definition (Property Form)

Description: Defines a boundary condition surface element with reference to a PHBDY entry.

Format:

Example:

Field	Definition	Type	Default
EID	Element identification number.	Integer > 0	Required
PID	Property identification number of a PHBDY entry.	Integer > 0	Required
TYPE	Surface type, see Remark 3.	Character	Required
IVIEW	A VIEW identification number.	Integer > 0
Gi	Grid point identification numbers of connection points of the surface.	Integer > 0
G0	Grid point identification number to optionally supply X1, X2, and X3. Direction of orientation vector is G1 to G0.	Integer > 0 or blank
RADMID	RADM identification number.	Integer > 0
CID	Coordinate system for defining orientation vector.	Integer > 0	0
Xi	Components of the orientation vector in the coordinate system defined in field 5. The origin of the orientation vector is a grid point G1.	Real or blank

Remarks:

1. Element identification numbers must be unique with respect to all other element identification numbers.
2. For types POINT and LINE geometric orientation is required. The required information is sought in the following order:
   • If G0 > 0 is found on the CHBDYP entry, it is used.
   • Otherwise, if a non-blank CE is found on the CHBDYP continuation entry, this CE and the corresponding vectors E1, E2, and E3 are used.
   • If none of the above apply, a warning message is issued.
3. All conduction elements to which any boundary condition is to be applied must be individually identified with the application of one of either surface element entries: CHBDYG or CHBDYP.
4. TYPE specifies the kind of element surface. Supported types are POINTS and LINE.
   • TYPE = POINT

     The POINT type has one primary grid point, requires a property entry, and the normal vector Vi must be specified.

     

     Figure 1. Normal Vector for CHBDYP Element with Type Equal to POINT

     The unit normal is given by:

     

   • TYPE = LINE

     The LINE type has two primary grid points, requires a property entry, and the vector is required.

     

     Figure 2. Normal Vector for CHBDYP Element with Type Equal to LINE

     The unit normal lies in the plane and , is perpendicular to , and is given by:

     

5. The geometric orientation can be defined by either GO or the vector E1, E2, E3.
   • If GO > zero:

     For a POINT-type surface, the normal to the front face is the vector from G1 to GO. For the LINE-type surface, the plane passes through G1, G2, GO and the right-hand rule is used on this sequence to get the normal to the front face.

   • If GO is zero:

     For a POINT-type surface, the normal to the front face is the orientation vector. For the LINE-type surface, the plane passes through G1, G2, and the orientation vector; the front face is based on the right-hand rule for the vectors G2 - G1 and the orientation vector.