- #1
bugatti79
- 794
- 1
Folks,
I have attached a picture illustrating the labelling of the linear reactangle element which can be represented by the following equation
##u(x,y)=c_1+c_2 x +c_3 y +c_4 xy## (1)
##u_1=u(0,0)=c_1##
##u_2=u(a,0)=c_1+c_2a##
##u_3=u(a,b)=c_1+c_2a+c_3b+c_4ab##
##u_4=u(0,b)=c_1+c_3b##
I don't really understand these equations. I mean, how is equation (1) derived to represent a rectangle and how is ##u_i## for ##i=1..4## derived?
Thanks
I have attached a picture illustrating the labelling of the linear reactangle element which can be represented by the following equation
##u(x,y)=c_1+c_2 x +c_3 y +c_4 xy## (1)
##u_1=u(0,0)=c_1##
##u_2=u(a,0)=c_1+c_2a##
##u_3=u(a,b)=c_1+c_2a+c_3b+c_4ab##
##u_4=u(0,b)=c_1+c_3b##
I don't really understand these equations. I mean, how is equation (1) derived to represent a rectangle and how is ##u_i## for ##i=1..4## derived?
Thanks