SURFACE

Surface Definition

Description: Shell element results coordinate system definition.

Format:

SURFACE id, SET esid, [SYSTEM system], [AXIS x-axis], [NORMAL normal]

Example:

SURFACE 12, SET 3, SYSTEM CORD 2, AXIS X, NORMAL Z

Option	Definition	Type	Default
id	Surface identification number.	Integer > 0	Required
SET esid	Element set identification number. Set identification of previously appearing SET command. Only shell elements whose identification numbers appear on this SET command will be included as part of the defined SURFACE. The character variable ALL may be used to specify all elements.	Integer > 0 or blank	Required
SYSTEM system	Coordinate system for results output, one of the following character variables: ELEMENT, BASIC, MATERIAL, GRID, or CORD followed by a coordinate system identification number.	Character or blank, or integer > 0	See Remark 3
AXIS x-axis	Surface x-axis definition, one of the following character variables: R, T, P, X, Y, or Z. See Remark 4.	Character	See Remark 3
NORMAL normal	Surface normal definition, one of the following character variables: R, X, Y, or Z. See Remark 4.	Character	See Remark 3

Remarks:

1. The SURFACE command is used to align element normals and define the output coordinate system for shell element and grid point results. A shell element must be defined on a SURFACE in order to have results calculated for it.
2. When the system option is equal to ELEMENT (or MATERIAL with no material coordinate system defined), element normals are not aligned and element results output is in the element coordinate system. Grid point results will default to the global coordinate system.
3. The default SURFACE is defined as ALL shell elements in the coordinate system specified by the ELEMRSLTCORD model parameter (default MATERIAL) and ALL shell element grid points in the global coordinate system.
4. AXIS and NORMAL are ignored when SYSTEM is set to ELEMENT or MATERIAL.