wrong result due to cantact set

help!help!help! I need your help.

when I used Explicit solver in Radioss to solve large deformation of Fabric .

I set MAT=LAW19 、N=1 in Pshell=TYPE9 (SH_ORTH) and set contact=type7 like this. 

result :

the Slave nodes group  and Master surface are both  the component itself.

how could I set the interface to fix this wrong?