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