Residual stresses in the glued structural members of wood

In the glued structural wood members the residual stresses that regularly appear could be caused by different reasons such as: the contraction of the glue volume during the hardening process, swelling of the wood during the gluing process, irregular geometric shapes of the glued members, pressures during the gluing process, etc. The residual stresses reduce the joint strength and it would be advisable to measure these stresses end thus find out the main reasons for their initiation. This paper investigates residual stresses caused by the contraction of the glue volume during the hardening process. The paper is a survey of a method of measuring the residual stresses in the glued structural members ofwood, and it also gives the results for PVAC glue and two techniques for woodworking the contact surfaces.