#
# Enforced Velocity Test
#
# Problem description
# An elastic steel rod has the velocity of one of its ends increased 
# from 0 to 1 m/s at time zero and thereafter held constant.
# The rod is otherwise unconstrained
#
# Model description
# One rod_2 element is used to model the rod.
# The timestep is scaled by 0.05 to ensure that oscillation should not
# make the solution unstable.
#
# Engineering data
#  Density          =   7850 kg/m3
#  Youngs modulus   =  210E9 N/m2
#  Poissons ratio   =    0.3
#  Rod Section Area =      1 m2
#
# Reference results
# Node 1 should move with a constant velocity of 1 m/s
# The rod should have a cyclic velocity with a mean value of 1 m/s, an 
# amplitude of 1 m/s and a period of 0.77E-3 s according to:
#
# Sound speed = sqrt(Youngs_modulus/density) = 5172 m/s
# Time for a sound wave to pass along a rod = 1/5172 = 0.193E-3 s
# Time for one period = 4*0.193E9 = 0.77E-3 s
#
# Comparisons of results
# Node 1 has a constant velocity of 1 m/s which corresponds with 
# theory.
# Node 2 results:
#
#                MSC-Dyna  Impact  Theory
# amplitude      1.0       1.0     1.0
# period         0.00086   0.00086 0.00077
#
#

nodes
1   x = 0  y = 0  z = 0  constraint = moving
2   x = 1  y = 0  z = 0

elements of type rod_2
1  nodes = [1,2]  material = mat1  D = 1.1284

materials of type elastic
mat1  E = 210000000000  rho = 7850  nu = 0.3

constraints of type boundary_condition
moving  vx = 1.0  ax = 0.0

trackers of type nodevelocity
1  node = [2]  direction = X  filename = Ver_07.trk target = [0.00043,0.000001,2.0,0.001]

controls
run from 0 to 0.002 step 0.000001
print every 0.0001 step
print tracker every 0.00001 step