Separation of elastic waves in split Hopkinson bars using one-point strain measurements

A method for the analysis of elastic waves in split Hopkinson bars for unlimited time durations is presented. This method allows the separation of component waves traveling in opposite directions in each bar using the strain history measured at one point on the bar and a known end condition for it. The method extends the time period for which valid experimental data can be extracted for a split Hopkinson bar apparatus and eliminates the need for a second independent measurement of the stress waves required in other methods for such extended analyses. Comparisons with the two-point method, which requires two independent strain measurements, show good agreement between the two methods. The accuracy and feasibility of the method are demonstrated through its application to impact experiments on composite laminates. The use of the current method in determining the response of a fiber-reinforced composite laminate under impact loading is described.