Dynamic characteristics of granite subjected to intermediate loading rate

X. B. Li, T. S. Lok, J. Zhao

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335 Citations (Scopus)

Abstract

A large diameter split Hopkinson pressure bar (SHPB) has been developed. This equipment is briefly described, together with a shaped striker that initiates a half-sine incident waveform to obtain the complete stress-strain relationship of the Bukit Timah granite at medium strain rate. Good constant strain rate was derived, and the dynamic complete stress-strain curves and energy absorption of the granite were measured at a strain rate between 20 and 60 per second. Repeated impact between 60-90% of the static strength of the granite was also conducted. Results from the tests show that the cumulative damage of the granite depends on the peak stress of the dynamic loads with a fixed duration. The dynamic fracture strength of the granite loaded at medium strain rate is directly proportional to the cube root of the strain rate. For the granite loaded at this strain rate, Young's modulus is unchanged. Energy absorption of the samples loading to fragmentation determined its fragmented size distribution. At high strain rate, the rock possesses large energy absorption and the particle size of the fragments is much smaller.

Original languageEnglish
Pages (from-to)21-39
Number of pages19
JournalRock Mechanics and Rock Engineering
Volume38
Issue number1
DOIs
Publication statusPublished - 1 Feb 2005
Externally publishedYes

Keywords

  • Cumulative damage
  • Dynamic complete stress-strain curves
  • Intermediate loading rate
  • Repeated impact
  • Rock dynamic characteristics

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