Impact loading of glued laminated timber beams without finger-joints.

Progressive collapse can be triggered by impact loading from vehicles or other objects and propagated by impact loading from falling debris. Therefore, the correct modeling of impact loading is necessary to assess the resistance of a structure against progressive collapse. As the number of timber buildings increases, the importance of adequate considerations of impact loading is growing. Previous research on impact loading of wood or timber was carried out on small clearwood specimens or on single boards. However, modern timber buildings use advanced wood-based composites, such as glued laminated timber and laminated veneer lumber. The characteristics of these materials are widely different from clearwood and single boards. In this paper, energy-based equations are derived for the peak impact force and the dynamic strength increase factor. These are quantified by pendulum impact hammer tests on 95 full-size glued laminated timber beams. The results are applied in a calculation example to demonstrate their potential use in practice. • Energy-based models for impact loading of timber beams are presented. • Results from 95 impact tests on full-size timber beams are discussed. • High-speed imagery reveals the impact process and five distinct failure modes. • The energy-release properties of timber beams are found to be strength class independent. • The dynamic increase or load duration factor is found for impact loading of timber beams. [ABSTRACT FROM AUTHOR]