[en] In order to verify the finite-element codes, a series of experiments has been performed under quasi-static and dynamic conditions. Preliminary tests demonstrated that for the range of deformations expected in a single subassembly prior to failure, a shortened duct section of only 30.48cm in length was sufficient to provide a central test section over which axially uniform conditions prevailed. The deformation over the uniform range corresponds to two-dimensional plane-strain conditions, and a two-dimensional computer code can be applied for the analysis. Additional tests were performed using a series of Type 316 stainless steel hexcan specimens in which the ductility was varied from a fully annealed specimen to a brittle specimen with a hardness corresponding to 50% cold working. The corresponding strains and displacements were measured at critical points such as the midflat region of maximum deflection and the duct corners where failure was expected. Dynamic tests of hexcans were also performed using a pressure-time source designed to duplicate a postulated local event. The local event simulated was the failure, after some period of operation, of misloaded, overenriched fuel pins. The fuel pin failure was postulated to result in the release of molten fuel into several subassembly subchannels. The resulting pressure pulse had the general characteristics of a 1msec risetime to a peak of about 100bar, with a total pulse width of about 5msec. Dynamic pulse loading experiments were then performed, in which the pressure pulse plus midflat and corner strains and displacements were measured. The material properties were also carefully determined for each specimen because of the high sensitivity of the hexcan response to the elastic modulus, the yield point and the plastic flow stress-strain relationship