Testing of Impact Limiters for Transportation Cask Design

Abstract

Abstract‘Soft Impact Limiters’ such as polyurethane foams and aluminum honeycombs are being studied to assist the Sandia National Lbiatory's Transportation Base Technology Program. The aim of this research is to study the mechanical behavior of these materials, which are being used as impact absorbers in nuclear waste transportation containers.A series of tests were performed along various loading paths using an Instron, servo-controlled, multi-axial loading machine and Soiltest triaxial testing apparatus. Static tests included uniaxial tension, uniaxial compression, triaxial compression, hydrostatic compression and fracture toughness testing. The purpose of using different loading paths was to generate an extensive test data which is being used to develop constitutive models for these materials, under a separate research program.Dynamic tests were conducted at strain rates of 100 strains/sec., to generate experimental data relevant to accident situations. These tests were conducted on an instrumented Charpy impact testing apparatus. Results of these tests were subsequently used to conduct scale-model tests of transportation casks of different industrial designers.Different densities of Polyurethane foams, aluminum honeycombs, and corrugated aluminum honeycombs were tested in different orientations. The paper discusses the experimental program, instrumentation and test results for the nuclear waste transportation industry and other potential applications.

Guidelines for conducting impact tests on shipping packages for radioactive material

“…Package made of strain-rate sensitive materials (Some materials used for the construction of shipping packages, such as lead and foam, show very different stress-strain relationships I when they are test under static and dynamic conditions (Chun et al, 1.991;Maji et al, 1990). Nevertheless, the change of strain-rates generated by the use of a scale model may not be sufficiently large to cause a significant change in the stress-strain relationships.…”