Real-Time and Quantitative Measurement of Crack-Tip Stress Intensity Factors Using Digital Holographic Interferometry

Figure 4

The unwrapped phase of the object wave through the PMMA specimen with a crack. (a)  = 1 MPa, (b)  = 1.5 MPa, (c)  = 2 MPa, and (d)  = 2.5 MPa.

(a)

(b)

(c)

(d)