Split Hopkinson bar measurement using high-speed full-spectrum fiber Bragg grating interrogation.
The development and validation of a high-speed, full-spectrum measurement technique is described for fiber Bragg grating (FBG) sensors. A FBG is surface-mounted to a split-Hopkinson tensile bar specimen to induce high strain rates. The high strain gradients and large strains that indicate material failure are analyzed under high strain rates up to 500  s-1. The FBG is interrogated using a high-speed full-spectrum solid-state interrogator with a repetition rate of 100 kHz. The captured deformed spectra are analyzed for strain gradients using a default interior point algorithm in combination with the modified transfer matrix approach. This paper shows that by using high-speed full-spectrum interrogation of an FBG and the modified transfer matrix method, highly localized strain gradients and discontinuities can be measured without a direct line of sight.
Frederick
F
Seng
Drew
D
Hackney
Tyler
T
Goode
LeGrand
L
Shumway
Alec
A
Hammond
George
G
Shoemaker
Mark
M
Pankow
Kara
K
Peters
Stephen
S
Schultz