# Experimental Study on Dynamics of Wooden House Wall Panels with Different Thermal Isolation
## 5 Conclusions  
The dynamic response of wall panels of a wooden frame building with two variants of insulation, mineral wool and polyurethane foam, has been experimentally studied. Firstly, the static compression and tension tests were conducted for the polyurethane foam. Then, the DMA tests were carried out so as to determine the basic thermomechanical properties of both analyzed isolation materials (mineral wool and polyurethane foam). Finally, the elements of exterior walls with two types of thermal insulation were tested under harmonic excitation for different amplitudes of displacement. On this basis, stiffness and damping ratios were calculated.  
Based on the results of the study, the following conclusions can be drawn:  
* Polyurethane foam behaves in a highly nonlinear way both during static compression and tension.
* Storage modulus of the polyurethane foam is significantly larger in relation to the value obtained for the mineral wool.
* Loss modulus of the polyurethane foam is much larger compared to the modulus of the mineral wool.
* Polyurethane foam, as a material, is able to absorb a greater amount of energy. Comparing it to the mineral wool, it is a material with much better energy absorption capabilities.
* The use of polyurethane foam as thermal isolation leads to a substantial increase in stiffness and damping properties of wall panels, compared to the mineral wood.
* The panel filled with the polyurethane foam passed all the tests without any damages, whereas the tests for the panel with the mineral wood were destructive.
* The use of polyurethane foam caused the integration of individual elements of the panel allowing it to behave as one element, increasing its strength and spatial rigidity.
* Damping properties of the polyurethane foam contributed to an increase in the dynamic resistance of the panel, since larger amount energy could be dissipated.  
Taking into account the above arguments, it is recommended to apply the polyurethane foam not only as an isolation material but also to increase the dynamic resistance of skeletal wooden structures. It can be used for newly constructed houses. It can also be applied in the case of existing wood-frame buildings since replacing the mineral wool with the polyurethane foam is relatively easy. The results of the investigation shown in this paper indicate that such an approach would be a very effective method of increasing the dynamic resistance of existing structures. Moreover, the polyurethane foam is a material widely available and increasingly used in civil engineering. It is also a relatively inexpensive and durable material compared to other insulation materials, which also makes it very attractive.  
Conceptualization, M.S. and R.J.; data curation, M.S.; formal analysis, M.S., W.M., and R.J.; methodology, M.S. and R.J.; writing--original draft, M.S. and W.M.; writing--review and editing, R.J.  
This research received no external funding.  
The authors would like to thank [PERSON] from STOLKAL Company for supplying the specimens used in the tests, as well as [PERSON] and [PERSON] for their help during the tests.  
The authors declare no conflict of interest.