Moisture Induced Stresses and Deformations in Parquet Floors - an Experimental and Numerical Study

Abstract: The indoor climate conditions in buildings have changed in the last decade due to more efficient climatic systems, floor heating systems and larger open floor areas with more natural light. These factors all give increased annual variations in the humidity and the temperature in parquet floors. Such variations can result in troublesome deformations, glue line delamination and development of cracks in the parquet flooring boards. In this master’s dissertation, the possibility of using the finite element method for deformation and failure prediction of parquet floors under changing climatic conditions was investigated. Several finite element models and also a simple beam model were created and applied. In addition, several experimental tests were made to study the deformation performance of parquet boards and to determine material parameters and to get information for calibration and validation of the theoretical model. After calibration and validation of the calculation method, parameter studies on the influence of material properties, geometry of the parquet floors and the long-term behaviour of the wood and glue line were performed in order to increase the understanding of the behaviour of parquet floors under changing climate. The results showed that the deformations and the stresses are strongly affected by the properties of the materials and by the geometrical design of the parquet boards. The deformations that are strongly affected include the gap opening. The stresses found may result in delamination of the surface layer. A parameter study of the long time behaviour of the parquet planks resulted in better understanding of the influence of creeping on the aforesaid deformations and failure modes.