# Experimental Study on Dynamics of Wooden House Wall Panels with Different Thermal Isolation
## 3 DMA Material Tests  
In the second stage of investigation, dynamic mechanical spectroscopy tests were performed using the DMA Q800 Instruments apparatus (Figures 5 and 6). The parameters of tests are presented in Table 1. It should be underlined that the range of temperatures and frequencies corresponded to real conditions. The loading protocol was taken according to standards ASTM D4092 and DIN 53440.  
Figure 4: Relation between stress and strain for polyurethane foam subjected to static tension (average of tested specimens).  
Figure 5: Test setup with dynamic mechanical analysis (DMA) Q800 analyzer.  
Figure 3: A sample made of polyurethane foam subjected to static tension.  
The results of the DMA tests (compression tests) are presented in Figures 7-14 and are summarized in Tables 2 and 3. The results show the change of storage modulus, loss modulus and loss factor (tan delta) as the temperature increases. It should be mentioned that the storage modulus measures the stored energy in the material due to the applied strain and represents the elastic portion of energy [34]. On the other hand, the loss modulus measures the energy dissipated through molecular motion and represents the viscous portion of energy. The ratio of the loss modulus to storage modulus is termed as the loss factor [34].  
The results of DMA tests (see Figures 7-14) clearly show that the values of storage and loss modulus were substantially larger for the polyurethane foam, as compared to the mineral wool. In particular, it can be seen from Tables 2 and 3 that, for the case of the temperature of 20 \({}^{\circ}\)C, the storage modulus of the polyurethane foam was larger by as much as 91.7%, 76.8% and 77.4% for the frequencies of 1 Hz, 10 Hz and 20 Hz, respectively. In turn, the loss modulus of the polyurethane foam was bigger than the corresponding value for the mineral wool by as much as 61.4%, 74.5% and 88.3% for the frequencies of 1 Hz, 10 Hz and 20 Hz, respectively. This indicates that the polyurethane foam, as a material, was able to dissipate a larger amount of energy. Therefore, comparing it to the mineral wool, it is a material with much better absorption capabilities related directly to the energy absorption.  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Specification** \\ \hline Dimensions of the test sample & Cylinder with a height of 10 mm and a diameter of 12 mm \\ Frequency range & From 1 Hz to 20 Hz \\ Heating speed & 4 \({}^{\circ}\)C/min \\ Temperature range & From \(-\)30 \({}^{\circ}\)C to \(+\)50 \({}^{\circ}\)C \\ \hline \hline \end{tabular}
\end{table}
Table 1: Parameters of DMA tests.  
Figure 6: Mounting of polyurethane foam in DMA Q800 analyzer.  
Figure 8: Results of DMA tests for mineral wool for frequency 1 Hz.  
Figure 7: Results of DMA tests for mineral wool for frequency 1 Hz.  
Figure 9: Results of DMA tests for mineral wool for frequency 20 Hz.  
Figure 11: Results of DMA tests for polyurethane foam for frequency 1 Hz.  
Figure 12: Results of DMA tests for polyurethane foam for frequency 10 Hz.  
Figure 10: Results of DMA tests for mineral wool; comparison for all frequencies analyzed.