This paper presents information regarding the distribution of critical stresses and regions where failure is likely to initiate in single bolt wood connections loaded in tension. Predicted stresses are the results of a three-dimensional numerical analysis of a connection consisting of a single steel pin and a wood member with a hole. Stresses of particular interest are: parallel-to-grain compression and shear and perpendicular-to-grain tension. Failure location is determined by considering the regions of the member where the material capacity is exceeded in at least one of the three aforementioned stresses. No stress interaction is assumed in this analysis.

A recently developed and verified three-dimensional (3-D) finite element model was used in this study. Important features of this model include a trilinear constitutive model of the nonlinear behavior of wood and a mechanism to describe the contact between the pin and the hole with changing connection load. The connection geometries studied included a single ratio of end distance to pin diameter (e∕ d = 4) and three bolt aspect ratios (length of bolt in wood member/bolt diameter) (l∕ d = 2, 5, and 7) .

Stress contours are illustrated on the 3-D wood member surface, on the contact surface, and on planes of symmetry. Pin and wood deformations are also illustrated.

The results show that for connections with an (l∕ d) = 2 , stresses are nearly uniform through the wood member thickness with negligible pin yielding. For connections with the larger bolt aspect ratios, considerably more pin bending and yielding is predicted with nonuniform stress distributions through the member thickness. The maximum stress failure criterion is found to be useful for comparing numerically predicted stress distributions to failure modes observed experimentally. By making these comparisons, it is possible to make qualitative interpretations of the critical stress states to indicate the regions where failure is likely to occur.