Large Dimension Hopkinson Pressure Bar and Its Application

In this paper,the most largest dimension split Hopkinson pressure bar(SHPB) at home is introduced.Some problems of large dimension SHPB technique used for measuring dynamic behaviors of concrete and concrete-like materials are discussed.The precision and reliability of testing results are heightened because several novel testing techniques are adopted,including: 1) a pulse shaper is settled at the free end of input bar;2) a gimbal is settled between specimen and bar;3) the stain of specimen is directly measured by strain gauge;and 4) a new date processing method is introduced.Impact compressive expressive experiments of high strength steel fiber reinforced concretes with four contents(0,2%,4% and 6%)under three strain rates(10~20/s,35~45/s and 75~85/s)are briefly introduced.The experimental results show that the high strength steel fiber reinforced concretes is more sensitive to strain rate.The destroy stress,peak strain and elastic modulus obviously increase with strain rate increasing.The content of steel fiber have toughening effect on the concrete materials,that is the toughness of concrete increases and its brittleness decreases with an increase of content of steel fiber.