DEVELOPMENT OF A DROP-WEIGHT-BULGE TEST, I

A laboratory test is described in which plate specimens could be 11 biaxially strained at relatively high loading rates to produce deformations similar to those observed in the explosion-bulge test plates. Results of extensive experimentation indicate that the deformation distribution observed in explosion-bulge test plates can be simulated in a 12-inch-thick plate if a 14-inch-square test specimen is placed on top of a 9-inch-inside-diameter anvil and impacted by a 5-12-inch-diameter hemispherical striker. The striker transmits an energy of 20,000 ft-lb to the plate through aluminum pads that distribute the strain throughout the plate bulge. Examination of dropweight-bulge specimens of a 12-inch-thick, 150 ksi yield-strength 5Ni-Cr-Mo-V steel showed that the strain field was uniform throughout a 2-inch-diameter polar region. The surface strain in this region was 0.2 inches inch and the thickness reduction was 30 percent. Thus, the drop-weight-bulge test appears suitable for evaluating the capacity of plates and weldments to deform under high strain 11 biaxial loading.