## 3 Component Tests
### Experimental Results
#### 3.3.1 Aluminium Skins  
Experimental data in terms of mid-point displacements, measured pressures and cross-sectional displacement profiles for the aluminium skins only are presented in Figure 8. The mid-point and cross-section displacements were obtained using 3D-DIC. All curves are corrected for the shock tube rigid body movement and shifted in time such that the time equals zero when the shock wave arrives at sensor S01. In the cross-sectional displacement profiles, plate velocity over the cross-section is indicated by the distance between each line, as the time interval is constant. The Mach number, maximum incoming pressure and reflected pressure measured at sensor S01 for each test are presented in Table 3.  
At the lowest load level, i.e., 10 bar firing pressure, the two skins behave as expected for plates subjected to a shock-tube blast load. The skins rapidly deform to a permanent maximum displacement of about 32 mm. The deformation begins with a uniform acceleration of the entire cross-section. The plate edges start to decelerate first, while the centre is still accelerating. After a small elastic springback from the peak displacement, the entire plate oscillates elastically around a permanent plastic displacement. The skins tested at 12 bar firing pressure had the same behaviour as the test with 10 bar firing pressure: a rapid deformation to a maximum mid-point displacement of 41 mm.  
At the highest load level tested, i.e., 15 bar driver pressure, the skins fail by tearing along the clamping frame edge. High-speed images of the failure process are shown in Figure 9. Failure initiates with tearing in the middle of both vertical edges at the frame and propagates vertically. After the tears have propagated along the entire height of both vertical edges, tearing initiates along the upper horizontal. The plate then fails along the upper horizontal edge, followed by the lower horizontal edge, before being ejected from the frame.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Test**} & \multicolumn{2}{c}{**Nominal Firing**} & \multirow{2}{*}{**Core**} & \(M_{s}\) & \(\mathbf{P_{S01,in}}\) & \(\mathbf{P_{S01,max}}\) & \(\mathbf{u_{max}}\) \\  & & **Pressure [bar]** & & **Material** & **[–]** & **[kPa]** & **[kPa]** & **[mm]** \\ \hline Sk\_P10 & & - & 1.46 & 167.9 & 378.4 & 33.3 \\ Sw\_250\_P10\_1 & & XPS-250 & 1.49 & 170.9 & 375.3 & 33.5 \\ Sw\_250\_P10\_2* & 10 & XPS-250 & 1.50 & 161.9 & 389.9 & 34.4 \\ Sw\_400\_P10 & & XPS-400 & 1.47 & 167.9 & 409.5 & 25.7 \\ Sw\_700\_P10 & & XPS-700 & 1.49 & 171.5 & 407.1 & 24.1 \\ \hline Sk\_P12* & & - & 1.57 & 198.9 & 461.8 & 41.2 \\ Sw\_250\_P12 & 12 & XPS-250 & 1.57 & 198.3 & 480.3 & 35.7 \\ Sw\_400\_P12 & & XPS-400 & 1.55 & 193.9 & 478.8 & 33.0 \\ Sw\_700\_P12* & & XPS-700 & 1.57 & 197.6 & 469.7 & 30.5 \\ \hline Sk\_P15 & & - & 1.59 & 218.5 & 512.7 & Failure \\ Sw\_250\_P15\_1 & & XPS-250 & 1.60 & 223.4 & 503.5 & 45.6 \\ Sw\_250\_P15\_2 & & XPS-250 & 1.61 & 224.0 & 508.4 & Failure \\ Sw\_400\_P15\_1 & 15 & XPS-400 & 1.60 & 226.4 & 549.9 & Failure \\ Sw\_400\_P15\_2 & & XPS-400 & 1.61 & 227.7 & 567.4 & Failure \\ Sw\_700\_P15\_1 & & XPS-700 & 1.61 & 227.7 & 523.1 & 36.2 \\ Sw\_700\_P15\_2 & & XPS-700 & 1.61 & 232.2 & 588.5 & Failure \\ \hline \hline \end{tabular}
\end{table}
Table 3: Test matrix and selected results from blast tests.