Whitmore Tension Section and Block Shear

Abstract

This paper examines the validity of the Whitmore net section tension capacity for the design of bolted gusset plates. Using simple algebra, this paper first shows that the Whitmore criterion and the correct block shear criterion would give similar results for a standard connection having approximately seven rows of bolts. It then shows that the Whitmore criterion severely underestimates the actual capacities of connections having two or three bolt rows tested by independent researchers. Conversely, it also shows that the same criterion overestimates the capacities of connections having nine bolt rows that were believed by the testing researchers to fail in the Whitmore section. Using finite-element analysis incorporating fracture simulation, this paper shows that the apparent Whitmore tensile fractures only took place because the tests were continued long after the ultimate limit state of block shear. This paper proposes that the Whitmore section check be made redundant in light of the block shear check, which accurately predicted the ultimate test loads of all the specimens.