Modification of the Kolsky method for studying properties of low-density materials under high-velocity cyclic strain

A modification of the Kolsky method with the use of the split Hopkinson bar is proposed, which allows testing low-density materials under cyclic loads of an identical sign. Cyclic dynamic testing of specimens is based on the essential difference of acoustic impedances of the material of the specimen tested from the material of pressure bars. The choice of the support-bar length several times greater than the loading-bar length allows registration of strain pulses in several cycles. Results are presented for the proposed modification of the Kolsky method used for tests in compression of foam plastic of two densities under three loading cycles.