The stress distribution in a steel-to-timber dowel joint loaded in tension parallel to the grain is

complicated and a lot of parameters are involved. Design variables as end distances, dowel spacing,

number of dowels per row, thickness of side members and steel dimensions have been discussed in

many papers and reports. How the load-bearing capacity of this type of joint is affected by moisture

induced stresses in the joint area has not been investigated to the same extent.

In the present study aspects of such behavior was discussed and was analyzed by use of numerical

methods. The joint considered was a steel-to-timber dowel joint in which one steel plate was

inserted in a slot in the timber and fitted by means of 18 steel dowels. The main aim was to

investigate in what extend moisture induced stresses, in this case generated by restrained shrinkage

deformations by the dowels (moisture case), interacts to the stress distribution generated when these

type of joints are loaded to failure parallel to the grain (mechanical case).

When comparing the numerical results of the mechanical case with the results of the moisture case,

it was found that the stresses perpendicular to the grain at several locations in the joint area

interacted to each other. For example, both the mechanical case and the moisture case indicated

tension stresses perpendicular to the grain in front of the dowels in the load-direction.

Experimental tests were seen as being needed in order to verify the numerical results obtained and

to investigate if the capacity of such joints can be reduced by this behavior. If it can be conclusively

shown that the load-bearing capacity of dowel-type joints are affected by restrained shrinkage

deformations this raises the important question of how such behavior can best be avoided and be

taken account of in design codes. Such moisture-induced stresses are probably best considered as a

load in design codes.