文档介绍：International Journal of Fatigue 23 (2001) 865–876
ate/ijfatigue
A structural stress definition and numerical implementation for
fatigue analysis of welded joints
P. Dong *
Center for Welded Structures Research, Battelle, Columbus, OH 43016-2693, USA
Received 10 December 2000; received in revised form 11 May 2001; accepted 12 June 2001
Abstract
A mesh-size insensitive structural stress definition is presented in this paper. The structural stress definition is consistent with
elementary structural mechanics theory and provides an effective measure of a stress state that pertains to fatigue behavior of
welded joints in the form of both membrane and ponents. Numerical procedures for both solid models and shell or
plate element models are presented to demonstrate the mesh-size insensitivity in extracting the structural stress parameter. Conven-
tional finite element models can be directly used with the structural stress calculation as a post-processing procedure. To further
illustrate the effectiveness of the present structural stress procedures, a collection of existing weld S-N data for various joint types
were processed using the current structural stress procedures. The results strongly suggests that weld classification based S-N curves
can be significantly reduced into possibly a single master S-N curve, in which the slope of the S-N curve is determined by the
position of the membrane and ponents of the structural stress parameter. The effects of membrane and
bending on S-N behaviors can be addressed by introducing an equivalent stress intensity factor based parameter using the structural
ponents. Among other things, the two major implications are: (a) structural stresses pertaining to weld fatigue behavior
can be consistently calculated in a mesh-insensitive manner regardless of types of finite element models; (b) transferability of weld
S-N test data, regardless of welded joint types and loading modes, can be established using the structural s