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.

[1]  Karl-Gustaf Sundin,et al.  Experimental study of a percussive process for rock fragmentation , 1989 .

[2]  J. M. Lifshitz,et al.  Data processing in the split Hopkinson pressure bar tests , 1994 .

[3]  B. Hopkinson.  A method of measuring the pressure produced in the detonation of high explosives or by the impact of bullets , 1914 .

[4]  P. S. Follansbee,et al.  Wave Propagation in the Split Hopkinson Pressure Bar , 1983 .

[5]  L. E. Malvern,et al.  Dispersion Investigation in the Split Hopkinson Pressure Bar , 1990 .

[6]  J. D. Campbell,et al.  Tensile Testing of Materials at Impact Rates of Strain , 1960 .

[7]  Bengt Lundberg,et al.  Analysis of elastic waves from two-point strain measurement , 1977 .

[8]  G. Ravichandran,et al.  Dynamic compressive failure of a glass ceramic under lateral confinement , 1997 .

[9]  R. Davies.  A critical study of the Hopkinson pressure bar , 1948, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[10]  H. Kolsky.  An Investigation of the Mechanical Properties of Materials at very High Rates of Loading , 1949 .

[11]  Sia Nemat-Nasser,et al.  Hopkinson techniques for dynamic recovery experiments , 1991, Proceedings of the Royal Society of London. Series A: Mathematical and Physical Sciences.

[12]  J. Achenbach.  Wave propagation in elastic solids , 1962 .

[13]  Han Zhao,et al.  On the use of SHPB techniques to determine the dynamic behavior of materials in the range of small strains , 1996 .

[14]  C. Yew,et al.  Strain-Rate Effects in the Propagation of Torsional Plastic Waves , 1966 .

[15]  J. Färm,et al.  Dynamic fracture toughness determined from load-point displacement , 1994 .

[16]  B. Hopkinson.  A method of measuring the pressure produced in the detonation of high explosives or by the impact of bullets , 2022 .

[17]  Gérard Gary,et al.  A new method for the separation of waves. Application to the SHPB technique for an unlimited duration of measurement , 1997 .

[18]  Karl-Gustaf Sundin,et al.  Analysis of elastic waves in non-uniform rods from two-point strain measurement , 1990 .