problem description
title="Isoparametric Sample Problem (Logan #7.11b, p.309)" nodes=5 elements=4

nodes
1 x=0      y=0   constraint=free
2 x=400e-3 y=0   constraint=free
3 x=400e-3 y=400e-3 constraint=pin
4 x=0      y=400e-3 constraint=pin
5 x=200e-3 y=200e-3 constraint=free force=point

iso2d_PlaneStress elements
1 nodes=[1,2,5,5,0,0,0,0,0] material=steel
2 nodes=[2,3,5,5,0,0,0,0,0]
3 nodes=[3,4,5,5,0,0,0,0,0]
4 nodes=[1,5,4,4,0,0,0,0,0] material=steel

material properties
steel e=210e9 nu=0.30 t=5e-3

forces
point fy=-30000

constraints
pin tx=c ty=c 
free tx=u ty=u

end