problem description
title="dynamic example" elements=2 nodes=3 analysis=transient

analysis parameters
mass-mode=lumped beta=1/6 gamma=0.5
duration=0.5 dt=0.05 nodes=[2,3] dofs=[Tx]

nodes
1 x=0 y=0 constraint=fixed
2 x=100   constraint=roller
3 x=200   constraint=roller force=linear

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

forces
linear Fx=2000 - t*4000

constraints
fixed Tx=c Ty=c Rz=C
roller Tx=u Ty=c Rz=u

material properties
steel E=1e6 rho=1.0 A=1.0 Ix=1.0

end
