An experimental program was undertaken to verify the end distance requirements in the Canadian standard for engineering design in wood for split ring connectors in joints loaded in compression. In a laboratory study, 48 joints of the Douglas fir-larch species group using 63 mm diameter split rings, 45 joints of the Douglas fir-larch species group using 102 mm diameter split rings, and 51 joints of the spruce-pine-fir species group using 63 mm diameter split rings were loaded to failure in compression. The split ring end distance varied between 50 and 200 mm for joints with 63 mm diameter split rings and between 80 and 220 mm for joints with 102 mm diameter split rings. Tests were also carried out to verify the cleavage strength of the wood and the strength of the wood in compression parallel-to-grain for each of the specimens. Results show that the end distance does not have any significant effect on the resistance of split ring connectors in joints with members loaded in compression. Key words: split ring, compression, end distance, timber, resistance.

An experimental study was undertaken to verify the combined effects of timber connector end distance and spacing requirements of the Canadian standard for engineering design in wood. A total of 130 test specimens using 63 mm diameter split rings were loaded to failure in tension. The split ring end distance varied between 50 and 210 mm and the spacing varied between 80 and 200 mm. Results show that a linear relation exists between the connector end distance and its resistance for a given spacing. Increase in spacing also results in an increase of the connector resistance for a given end distance. Also, connections with two connectors in a row can resist significant loads even if the end distance or spacing of one connector is below the standard minimum required value. Thus, the design philosophy of Clause 10.3.3 of the wood design standard is inadequate for these joints.

In this paper, an experimental study of the behavior of 102 mm shear plates subjected to tensile load is presented. The design requirements for shear plate connectors specified in the last three editions of the Canadian wood design standards (1980, 1984, and 1989) are also reviewed and compared with the experimental results. In the experimental study, 83 specimens were tested with shear plate end distances of 80, 145, 210, and 275 mm. Specimens were either 64 or 89 mm thick. Results for all tests were analyzed and 5th percentile resistance values were obtained for each end distance value, assuming a two-parameter Weibull distribution. Results show that connections using 102 mm shear plate connectors behave in a brittle manner when loaded in tension. It is also shown that the member thickness affects the tensile resistance of shear plates in thin members with small connector end distances and that it appears to impose a limit on the resistance for thin members with large connector end distances. Finally, it is shown that the 75% minimum limit on a member net area adjacent to a connector unit (clause 4.3.7.2 of O86.1-M89) is conservative for members with small connector end distances. Key words: wood, shear plate, end distance, resistance, thickness.