The paper presents a description and results of the research concerning one of the
scarf joints, so-called ‘lightning sign’ (also described as ‘Bolt of lightning’ or ‘Trait-de-
Jupiter’). This joint has been used and can be commonly found in wooden historical structures
and is considered to be an interesting example of carpentry longitudinal joints. In the
experimental part timber beams with this type of joint shaped in the different planes, horizontal
and vertical, reinforced with spindle fasteners (metal bolts), were subjected to four-point
bending tests. As a result, the static equilibrium paths and the bending capacities of individual
beams were obtained. They were compared to the load-bearing capacity of the continuous
reference beam. Moreover, a simplified numerical analysis based on FEM was carried out for
comparison the rigidity of individual beams. A comparison of the results for series of beams is
discussed and some conclusions and possible directions of the future actions in the subject are
presented.
Abstract
The paper presents a description and results of the research concerning one of the
scarf joints, so-called ‘lightning sign’ (also described as ‘Bolt of lightning’ or ‘Trait-de-
Jupiter’). This joint has been used and can be commonly found in wooden historical [...]