# Vibro-Acoustic Numerical Simulation for Analyzing Floor Noise of a Multi-Unit Residential Structure
## 4 Summary & Conclusions  
This study performed a vibro-acoustic analysis of multi-unit residential structures. During this study, a numerical structural model has been developed, that can be used for numerically analyzing floor noise occurring inside a multi-unit residential building. Noise evaluation of a target model (the 17-story structure) was carried out using a numerical analysis. The results of the vibration and acoustic analyses were compared in terms of 1/3 octave bands, 1/1 octave bands, and SNQs.  
For the purpose of the proposed vibro-acoustic analyses, field measurements were carried out and a comparison with the numerical simulation results was conducted. The comparison results show that the results of the vibro-acoustic analysis exhibited a reasonable accuracy.  
On the basis of the above results, it is clear that the numerical simulations using the proposed approach can replace field experiments that demand time and money. Additionally, numerical simulations can be applicable in practical situations and future researches, such as analyzing noise-transmission paths inside multi-unit residential buildings and determining community structures, floor plate types, and wall locations, all of which can be carried out using the proposed approach.  
This work was supported by the National Research Council of Science & Technology (NST) grant by the Korea government (MSIP) (No. CRC-16-02-KICT).  
The author acknowledges Altair Korea, Inc. for their invaluable comments and technical support on the numerical analysis during this study, and appreciates the anonymous reviewers for their helpful comments and suggestions.  
The authors declare no conflict of interest.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Type**} & \multirow{2}{*}{**Section**} & \multicolumn{3}{c}{**1/1 Octave Band**} & \multicolumn{1}{c}{**Frequency (dB)**} & \multirow{2}{*}{**SNQ**} \\ \cline{3-3} \cline{5-6}  & & **63 Hz** & **125 Hz** & **250 Hz** & **500 Hz** \\ \hline \multirow{3}{*}{\
\begin{tabular}{c} Numerical \\ simulations \\ \end{tabular} } & Impact sound pressure level & 85.9 & 66.5 & 57.2 & 42.0 \\ \cline{2-6}  & Normalized curve of inverse & \multirow{2}{*}{78} & \multirow{2}{*}{68} & \multirow{2}{*}{61} & \multirow{2}{*}{55} \\  & A weighted & & & & \\ \cline{2-6}  & Excess value of normalized & \multirow{2}{*}{7.9} & \multirow{2}{*}{0} & \multirow{2}{*}{0} & \multirow{2}{*}{0} \\  & curve & & & & \\ \hline \multirow{3}{*}{
\begin{tabular}{c} Field \\ measurements \\ \end{tabular} } & Impact sound pressure level & 80.3 & 64.4 & 53.7 & 46.9 \\ \cline{2-6}  & Normalized curve of inverse & \multirow{2}{*}{74} & \multirow{2}{*}{64} & \multirow{2}{*}{57} & \multirow{2}{*}{51} \\  & A weighted & & & & \\ \cline{2-6}  & Excess value of normalized & \multirow{2}{*}{6.3} & \multirow{2}{*}{0.4} & \multirow{2}{*}{0} & \multirow{2}{*}{0} \\  & curve & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: Results of the vibration-acoustic analysis (1/1 octave band) and SNQ values for field measurements and numerical simulations of the 17-story structures.