problem description
title="Beam Sample Problem (Logan #5.5, p.188)" nodes=3 elements=2 

nodes
1 x=0   y=0 force=point_load   constraint=free
2 x=240 y=0 constraint=roller
3 x=480 y=0 constraint=fixed

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

material properties
steel e=30e6 ix=100 a=10

forces
point_load fy=-1000

constraints
roller tx=u ty=c rz=u
fixed tx=c ty=c rz=c
free tx=u ty=u rz=u

end