## 8 Impact and Shock Measurements on Critical Structures
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Milestone** & **Author(s)** & **Observational Subject** & **Tools/Instrument** & **Important Remarks** \\ \hline
2010 & [PERSON] et al. [136] & \begin{tabular}{c} Coal dust explosion in \\ mine sites \\ \end{tabular} & \
\begin{tabular}{c} Kistler piezoelectric \\ pressure sensor \\ Experimental tube \\ \end{tabular} &
\begin{tabular}{c} Combustion and explosion of \\ fine particle coal dust with \(\mathcal{O}\) \\ 45–70 \(\upmu\)m was observed faster \\ than that of coarse particle with \\ \(\mathcal{O}\) 70–105 \(\upmu\)m. \\ \end{tabular} \\ \hline
2011 & [PERSON] et al. [137] & \begin{tabular}{c} The explosion of \\ methane–air mixtures \\ \end{tabular} & \
\begin{tabular}{c} Pressure sensor \\ High-speed camera \\ Explosion vessel \\ \end{tabular} &
\begin{tabular}{c} Methane/air mixture could be \\ ignited in the vessel by 40-J \\ electric spark when the methane \\ concentration was \\ approximately 5–13\%. \\ \end{tabular} \\ \hline
2012 & [PERSON] and \begin{tabular}{c} [PERSON] [138] \\ \end{tabular} & Steel hull–ice collision & \
\begin{tabular}{c} I-Scan 210 tactile \\ sensors \\ \end{tabular} &
\begin{tabular}{c} Methane/air mixture could be \\ ignited in the vessel by 40-J \\ electric spark when the methane \\ concentration was \\ approximately 5–13\%. \\ \end{tabular} \\ \hline
2014 & [PERSON] et al. [139] & \begin{tabular}{c} Naval vessel’s multi-layer \\ protective structure under \\ blast and fragment \\ loadings \\ \end{tabular} & \
\begin{tabular}{c} Sensors: \\ Strain gauge \\ Accelerometer \\ \end{tabular} &
\begin{tabular}{c} Stiffened plates were found to be \\ easily penetrated by fragments. \\ It is different compared to the \\ thick structure, to which the \\ fragments only caused localized \\ damage. \\ \end{tabular} \\ \hline
2015 & [PERSON] et al. [140] & \begin{tabular}{c} Sandwich beams under \\ low-velocity impact \\ (representation of ship \\ collision and grounding) \\ \end{tabular} & \
\begin{tabular}{c} Phantom V12 camera \\ Force sensors \\ \end{tabular} &
\begin{tabular}{c} Post-peak responses for the \\ drop-weight and quasi-static \\ measurements were very similar, \\ which indicates that the beam \\ response is not sensitive to the \\ material strain rate or inertial \\ effects for impact velocity of \\ approx. 5 m/s. \\ \end{tabular} \\ \hline
2016 & [PERSON] [141] & \begin{tabular}{c} Steel–concrete–polymer \\ (SCP) composite \\ barrier under corrosion \\ and impact \\ \end{tabular} & \
\begin{tabular}{c} AMSYS system \\ VS30-V VS75-V sensors \\ Displacement gauges \\ \end{tabular} &
\begin{tabular}{c} SCP structures were still in a \\ tight condition until undergoing \\ 5 times deeper penetration \\ compared to the initial state. \\ \end{tabular} \\ \hline
2017 & [PERSON] et al. [142] & \
\begin{tabular}{c} Ship structure subjected to \\ the underwater explosion \\ (UNDEX) \\ \end{tabular} &
\begin{tabular}{c} Analyo–digital converter (ADC) \\ resolution may be low in the \\ condition where the sampling \\ rate is very high. On the other \\ systems: \\ NI 9234 \\ NI-PXIe-4497 \\ NI PXIe-5160 \\ \end{tabular} \\ \hline \end{tabular}
\end{table} 
Table 11: Summarized findings of the sensor-based research on measuring impact and shock. In 2021, research on impacts and sensors was marked by an experimental study on aluminum plates [146]. The novelty of this work is in the specimen used, which underwent pre-cracked treatment. The primary purpose of this crack was to quantify slight defects in the dynamic response and damage degree. The launchings system embedded the experimental installation to accelerate the steel flyer plate to achieve a high speed before it flew out from the launching tube and impacted a steel piston in the starting side of the underwater shock tube.