Sampat Kumar
Ansys Employee

Hi Ayeon , 
Will you please check the connection that you have applied for? Please establish contact between the two parts. Are you seeing the result on a large scale? I would recommend you see the result on a true scale.

You can adjust the pinball radius to detect the contact between the inner and outer geometry. You will find the pinball radius option in the contact details. You can also check the status of the contact by using the contact tool.