Theoretical and experimental research of external prestressed timber beams in variable moisture conditions

Hybrid girders can be constructed in different geometrical forms and from different materials. Selection of beam\'s effective constellation represents a complex process considering the variations of geometrical parameters, changes of built in material characteristics and their mutual relations, which has important effect on the behavior of the girder. This paper presents the theoretical and experimental research on behavior of the timber-steel hybrid girders\'different geometrical constellation with external prestressing and in different conditions of timber moisture. These researches are based on linear elastic analysis, and further refine by using the plasticity and damage models.