Study on Crack Propagation of the Tunnel Model under Dynamic Loading

Table 1

Mechanical properties of the PMMA.

Mechanical properties	Symbols	Units	PMMA
Density		kg/m^3	1180
Dynamic Young’s modulus	Ed	GPa	6.1
Poisson’s ratio	Vd	−	0.31
Velocity of compressive waves	Cp	m/s	2320
Velocity of shear waves	Cs	m/s	1260
Stress optical constant	C	m^2/N	0.88 × 10^−10
Shear modulus	G	GPa	1.28