problem description
title="Thin Pin-Pin Beam" 
nodes=3 elements=2 analysis=static-substitution

analysis parameters
load-steps = 10     tolerance = 0.001     
iterations = 50     relaxation = 1.0

nodes
1 x=0	y=0	constraint=pin
2 x=120 y=0	constraint=free    force=point
3 x=240	y=0	constraint=pin

beam elements
1 nodes=[1,2]	material=steel
2 nodes=[2,3]

material properties
steel E=10e6 A=0.785 Ix=0.05

constraints
pin    Tx=c Ty=c Rz=u
free   Tx=u Ty=u Rz=u

forces
point   Fy=-10

end
