Stress distribution during the delamination of lap joints in a bending test

The main goal of this paper was to determine the distribution of stresses in wood lap joint in double-cut samples. During the performed laboratory tests, the authors determined the force destroying the joint. This force, in turn, was used to determine the value and distribution of stresses with the assistance of analytic and numerical methods. Numerical calculation were done using finite element method and brick type elements. Based on analytic model a computer program was written. The distribution of stresses in the glue bond of a lap joint in the course of bending of a double-cut sample shows strong concentration of both normal and tangential stresses at the end of laps. In conclusion it was stated that the mean value of normal stresses in the glue line can be assumed as its peeling strength of double cut wood sample. This value determined numerically amounted to 8.2 MPa.