Due to lack of Kronecker delta property in EFG, shape function UI poses some difficulty in the imposition of essential
boundary conditions. To remove this problem, different numerical techniques have been proposed to enforce the essential
boundary condition in EFG method such as Lagrange multiplier technique, modified variational principle approach, penalty
approach etc. But penalty method is easy to implement rather than other techniques. So, penalty method [27] is applied
which is discuss as follows