Coupling for wood structural members

A connection system, comprising:

• a wood structural member having an opening with a substantially tubular cross-sectional configuration defined by an inner surface and an outer surface;
• a connector for insertion into the wood structural member, the connector having a substantially tubular first end with a cross-sectional configuration that matingly corresponds to the tubular cross-sectional configuration of the opening in the wood structural member located within the opening in the wood structural member and a second end for connection to another structural member, the first end having an inner connecting surface and an outer connecting surface, the first end of the connector being dimensioned to substantially fill the opening in the wood structural member so that the outer surface of the opening opposes the outer connecting surface of the connector and the inner surface of the opening opposes the inner connecting surface of the connector leaving a small gap therebetween;
• an adhesive located within the gap and covering the inner and outer connecting surfaces of the connector and the inner and outer surfaces of the opening, the adhesive forming a connection interface to secure the first end of the connector within the opening and thereby directly transmit internal or external load forces from the wood structural member to the connector;
• and
• wherein the tubular first end of the connector has at least one discontinuity that creates a local widening portion in the gap between the inner and outer connecting surfaces of the connector and the inner and outer surfaces of the opening and that cooperates with the adhesive to allow expansion and contraction of the wood structural member so that the connection interface between the connector and the wood structural member remains intact through dimensional variations of the wood structural member.