DYNAMIC SHOCK ABSORBING PROPERTY OF REDWOOD FOR TRANSPORT/STORAGE CASKS

The impact compressive tests for redwood were performed supposing the actual drop test condition and the energy absorbing property data were obtained. These tests include the static/dynamic conditions. In the dynamic test, the deformation speed according to the behavior of woods under the 9m drop test is simulated. It was confirmed that these woods could be the suitable materials for energy absorbing and useful for the design of effective shock absorber. As for the redwood, the impact crush tests were performed not only in room temperature but also -20 and 70 o C and the energy-absorbing characteristic including the dependency of temperature was evaluated. The dynamic compressive stress of redwood with -20 o C is approximately maximum 30% larger and the value with 70 o C is approximately maximum 25% smaller than that of room temperature. These values are smaller than the compressive stress data published in literature, it has a little of influence on the design of the shock absorbing covers. These tested properties and the influence on the design of the shock absorbing covers are discussed in the paper.