Numerical modelling and strength prediction of welded double lap joints made of timber

Welding of wood is a relatively new method of joining load bearing elements, which holds the potential to compete with structural adhesion, since it allows for an almost instantaneous bond. First experimental and numerical investigations showed that failure of wood-welded connections is linked to a combination of shear and transverse-tensile stresses in the welded interface. One of the main conclusions drawn from previous investigations is the inability of simple stress-based approaches to allow for an estimate of strength, which is due to the huge stress peaks generated in such joints. To achieve a reliable dimensioning of wood-welded joints, it is paramount to determine the stress-strain state inside the connection, taking into account the mechanical complexity of the involved components, to determine the mechanical resistance towards the acting stresses and to combine both in the framework of a strength prediction routine. This paper addresses the aforementioned issues by summarizing experimental and numerical results on wood-welded joints, suggesting an experimental method to characterize the strength of the welded interface, and combining the previous results in the form of a strength prediction method. Lastly, experimental and numerical results are compared, which allows for a validation of the suggested approach.