1. Distinguish between geometric and
material non-linearities. Give an example of each. Using your favorite
FEM code solve the following problem:
a) assumiong linear elastic small deformation model.
b) accounting for the material and geometric non-linearities.
c) Comment on the choice of material model and effect of incorporating
the geomtric non-linearity.
d) If the code permits, try different non-linear solution schemes Newton-Rhapson
etc. Comment on convergence.
2. (Exercise 4 pg 474 in T. J. Hughes )
Consider M du/dt + K d = 0
For the following variant of the Generalized trapezoidal algorithm
a) What is the amplification factor ?dn+1 = dn + rvn + r2/2 an
M vn+1 + K dn+1 = 0
M an+1 + K vn+1 = 0
r is the time step (delta t)