[en] The effects of postulated high-energy pipe rupture must be evaluated in the design of nuclear power plants. Methods for evaluating one aspect of this accident, pipe whip, and restraint impact, require solutions based on non-linear inelastic dynamics. Since no suitable analytical techniques or computer programs were then available, Stone and Webster undertook the development of such a capability. An important phase of this effort was an experimental program to justify the adequacy of the computer code. The results of these experiments and a comparison with analytical predictions are provided. (Auth.)