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