The following references were consulted when creating this example problem:
Carpenter, N.J., Taylor, R. L, & Katona, M. G. (1991). Lagrange constraints for transient finite element surface contact. International Journal for Numerical Methods in Engineering. 32: 103-128.
Hallquist, J.O. & Benson, D. J. (1987). DYNA3D user's manual, revision 3. Report No. UCID-19592. Lawrence Livermore National Laboratory.
Kamoulakos, A. (1990). A simple 'benchmark' for impact. Bench Mark. 31-35.
Simo, J.C. (1998). Algorithms for static and dynamic multiplicative plasticity that preserve the classical return mapping schemes of the infinitesimal theory. Computer Methods in Applied Mechanics and Engineering. 68: 1-31.
Wilkins, M.L. & Guinan, M. W. (1973). Impact of cylinders on a rigid boundary. Journal of Applied Physics. 44.3: 1200-1206.