problem description
title="Isoparametric Sample Problem (Logan ex. 8.2, p.336)" 
nodes=4 elements=1

nodes
1 x=3   y=2   
2 x=5   y=2   
3 x=5   y=4  
4 x=3   y=4   

iso2d_PlaneStress elements
1 nodes=[1,2,3,4,0,0,0,0,0] material=steel

material properties
steel e=30e6 nu=0.25 t=1.0 rho=0.283

end
