Title:
Crack Protocols for Anchored Components and Systems
Author(s):
Richard L. Wood and Tara C. Hutchinson
Publication:
Structural Journal
Volume:
110
Issue:
3
Appears on pages(s):
391-402
Keywords:
anchor; crack cycling protocol; cracked concrete; fastener; rainflow counting; seismic
DOI:
10.14359/51685597
Date:
5/1/2013
Abstract:
The opening and closing of cracks in concrete, also referred to as “crack cycling,” can be induced during an earthquake and has been shown to significantly influence the tension behavior of anchors. This paper presents a protocol for testing anchors in cycling cracks in an effort to represent earthquake loading of anchored components and systems. In the proposed protocol, cyclic cracking is simulated while a representative tension or shear load history is simultaneously applied. The protocol is developed by performing rainflow counting of the curvature histories extracted from nonlinear history analyses of a suite of building models. Herein, the focus is on development of the crack histories; loading histories are outside the scope of this paper. The selection of earthquake motions is guided by results from a probabilistic seismic hazard analysis of a seismically active region in Southern California. The resulting cyclic crack protocol is presented in statistical terms and an example application of these statistics to the assessment of anchors used in bracing nonstructural components and systems is provided.