Influence of insect damage to the fatigue life of an old larch wood

In many cultural heritage buildings, structural members are made of wood. Over the years, wood is exposed to various biotic and abiotic degradation factors, including moisture oscillations, mechanical stress, and insect and fungal decay. In the present respective study, an experimental study on the fatigue life of 350 years old larch wood was carried out. The fatigue life of the old wood was compared to the fatigue life of the recent larch wood. A statistical model for the fatigue-life curves and their scatter was built for both kinds of wood. The model can consider different factors to the fatigue life, e.g. wood density, specimen orientation during loading, and extent of insect damage. An equivalent number of load cycles to failure was also defined, enabling a direct comparison of the fatigue life data for specimens with different wood densities or orientations during loading. From the results, it can be concluded that the proposed statistical model adequately describes the fatigue behaviour of both the old, insect-damaged wood and the recent larch wood.

Automated summary

An experimental study was conducted to compare the fatigue life of 350-year-old larch wood with that of recent larch wood. A statistical model was developed to describe the fatigue-life curves and scatter for both types of wood. The model takes into account factors such as wood density, specimen orientation, and extent of insect damage. The results indicate that the proposed model adequately describes the fatigue behavior of both old, insect-damaged wood and recent larch wood.