Journal Published Online: 01 September 1998
Volume 26, Issue 5

Qualitative Assessment of Failure in Bolted Connections: Tsai-Wu Criterion



In a companion paper, a characterization is presented of stress fields in a single-shear bolted connection subjected to tension loading. Numerous stress contours are presented that illustrate the magnitude of the parallel-to-grain compression and shear stresses, as well as the perpendicular-to-grain tension stresses. In addition, regions of potential failure in the selected specimens are identified based on a maximum stress failure criterion.

The work presented in this paper represents additional efforts to identify the effect of stress interactions on the strength of the previously mentioned connections. The Tsai-Wu criterion, quantified by its failure index, is used as the tool to identify stress interactions between the aforementioned stress components. Connection geometries similar to those discussed in the companion paper [end distance/bolt diameter (e d) = 4 ; and length of bolt in main member/bolt diameter (aspect ratio) (l d) = 2, 5, and 7 ] are studied. In addition, several other geometries are discussed that illustrate the effects of changing aspect ratio and end distance.

A number of significant findings are reached in this study. As is the case in the companion study, all connections with (l d) = 2 have nearly uniform distributions of the Tsai-Wu failure index (FI) through the specimen thickness. No significant pin bending is associated with this geometry. Connections with ld > 4 have a failure mode (interpreted from the numerical model) that includes substantial pin bending due to steel yielding, wood crushing, and localized cracking.

Author Information

Patton-Mallory, M
USDA Forest Service, Fort Collins, CO
Pellicane, PJ
Colorado State University, Fort Collins, CO
Smith, FW
Colorado State University, Fort Collins, CO
Pages: 9
Price: $25.00
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Stock #: JTE12694J
ISSN: 0090-3973
DOI: 10.1520/JTE12694J