Vibrationer och svikt i KL-träbjälklag : En jämförelse mellan beräknade och experimentellt uppmätta värden

Sammanfattning

The use of timber in construction has increased significantly in recent years, with crosslaminated timber (CLT) becoming a common structural material. Due to its relatively low stiffness compared to other building materials, specific challenges arise in the design process, particularly concerning vibrations and deflection in floor systems caused by human activity. These factors are considered during the design phase, but previous studies have shown that design calculations tend to be conservative and often do not correspond well with the actual in-use performance of completed buildings. The purpose of this study is to investigate the differences between theoretically calculated and experimentally measured values for natural frequency and acceleration in a CLT floor system. Measurements were carried out on an existing building, and the results were compared to values obtained from both manual and computer-based calculations performed in accordance with Eurocode 5. The findings indicate that natural frequency can be reasonably well predicted through calculations, while acceleration shows significant discrepancies. These differences are partly explained by the simplified assumptions and models used in the calculations, whereas real structures are influenced by a broader range of parameters. The conclusion is that current calculation methods have limited reliability in predicting vibrations and deflection in CLT floors, and further research is needed to improve understanding and accuracy during the design stage.