Knowledge Bank

A Split Hopkinson Bar is an apparatus that is used to test materials at high strain rates. The typical Split Hopkinson Bar has a length of 6 meters and runs tests at a strain rate between 500 s-1 and 5,000 s-1. The limitation of testing at a maximum strain rate of 5000 s-1 is becoming more of a problem as technology develops in fields such as space travel or weapon defense. In fields such as these, knowing exactly how a material will react in application is crucial to success. For example, a bullet striking a bullet proof vest creates a strain rate in the range of 104 s-1[6]. With current material testing technologies, engineers are unable to know exactly how the material will react in this situation. In order to fix this issue, an apparatus needs to be created which can test materials at strain rates greater than 5000 s-1. This report focuses upon the design, manufacture, and testing of a Miniature Split Hopkinson Bar. This device alleviates the aforementioned strain rate restraint for certain materials. The Miniature Split Hopkinson Bar is designed to a size of four feet in length and has the ability to test materials at a strain rate of 104 s-1.