LOM DRVENIH KONSTRUKCIJA: ANALIZA TIPIČNIH OBLIKA LOMA I NJIHOVIH MOGUĆ IH UZROKA

Abstract

Damages or failures in timber structures have created a negative image for timber as a building material. This can raise speculations and doubts about the safety level of existing timber structures. The objective of this paper is to identify typical failure modes and their causes. Experiences from previous failure investigations are summarised. Bending failures and tension perpendicular to the grain failures are common failure modes for beams. The main type of damage affecting the integrity of cross-sections is cracking along the grain. Causes for such damages are related to overloading, frequently changing wood moisture content and tensile stresses perpendicular to the grain resulting from geometry of structural elements. In the case of failure of trusses, frames and arches dominant failure mode is instability caused by insufficient bracing. The majority of failures can be linked to design and construction errors. Manufacturing errors (wood quality, production principles and methods) only cause a small number of the failures. In order to minimise or avoid errors and thereby occurrence of failures, different recommendations are given.