RTHICK, Par, ILOC, JLOC, KLOC, LLOC
Defines variable thickness at nodes for shell elements.
ParArray parameter (indexed by node number) that expresses the function to be mapped. For example, func (17) should be the desired shell thickness at node 17.
ILOCPosition in real constant set for thickness at node I of the element (default 1).
JLOCPosition in real constant set for thickness at node J of the element (default 2).
KLOCPosition in real constant set for thickness at node K of the element (default 3).
LLOCPosition in real constant set for thickness at node L of the element (default 4).
After RTHICK, the
REAL number will match the ELEM number of each selected element. For example, R (ILOC) = func (I
NODE), R (JLOC) = func (J NODE), etc. 
R(ILOC), R(JLOC), R(KLOC), and R(LLOC) on a previously defined real constant will be
overwritten.  Any other real constants on a previously defined real
constant set will remain unchanged. This command cannot be used for
beam elements.