TY - JOUR
T1 - Formation of post-buckling shear mechanisms in stiffened web panels of slender steel plate girders
AU - Augustyn, Kevin E.
AU - Quiel, Spencer E.
AU - Garlock, Maria E.M.
N1 - Funding Information:
This research was sponsored by the National Science Foundation (NSF), United States of America under grants CMMI-1662886 and CMMI-1662964 . All opinions expressed in this paper are the authors’ and do not necessarily reflect the policies and views of NSF.
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2023/3
Y1 - 2023/3
N2 - A series of validated finite element models are used to investigate the formation of mechanisms in stiffened slender web panels of steel plate girders under pure shear. The prototype girder is based on the seminal tests by Basler and has a web slenderness of 267. Six model cases are analyzed with variations in web panel aspect ratio (1, 1.5, and 3), steel yield strength (Grades 36 and 50), initial imperfection magnitude, and flange thickness. When loaded in shear, the web panels exhibit a 3-stage response: (1) elastic behavior, (2) web mechanism formation, and (3) panel mechanism. In Stage 1, the web initially exhibits an elastic in-plane shear response with no distinct buckling bifurcation. During this stage, the web's initial out-of-plane imperfections become engaged in second-order bending along its compression diagonal. Concurrently, tension develops in the opposite diagonal as a non-uniform membrane stress field, with highest intensities at locations where second-order bending is low. In Stage 2, a web mechanism is formed when connected bands of thru-thickness von Mises yielding develop across the tension diagonal. These bands emerge at locations where tension membrane stresses interact with locations of maximum second-order bending stress in the buckled shape. The shear load at the end of web mechanism formation is recommended as a target for plastic limit state design because it marks a significant decrease in shear stiffness. In Stage 3, von Mises yielding continues to saturate the web panel, and the bounding flanges and transverse stiffeners become increasingly engaged in load redistribution from the plastified web. Any hardening increase in shear resistance during the panel mechanism stage is modest in magnitude (up to ∼10% for some cases in this study) and is heavily dependent on the sizing of the flanges and stiffeners to carry redistributed forces.
AB - A series of validated finite element models are used to investigate the formation of mechanisms in stiffened slender web panels of steel plate girders under pure shear. The prototype girder is based on the seminal tests by Basler and has a web slenderness of 267. Six model cases are analyzed with variations in web panel aspect ratio (1, 1.5, and 3), steel yield strength (Grades 36 and 50), initial imperfection magnitude, and flange thickness. When loaded in shear, the web panels exhibit a 3-stage response: (1) elastic behavior, (2) web mechanism formation, and (3) panel mechanism. In Stage 1, the web initially exhibits an elastic in-plane shear response with no distinct buckling bifurcation. During this stage, the web's initial out-of-plane imperfections become engaged in second-order bending along its compression diagonal. Concurrently, tension develops in the opposite diagonal as a non-uniform membrane stress field, with highest intensities at locations where second-order bending is low. In Stage 2, a web mechanism is formed when connected bands of thru-thickness von Mises yielding develop across the tension diagonal. These bands emerge at locations where tension membrane stresses interact with locations of maximum second-order bending stress in the buckled shape. The shear load at the end of web mechanism formation is recommended as a target for plastic limit state design because it marks a significant decrease in shear stiffness. In Stage 3, von Mises yielding continues to saturate the web panel, and the bounding flanges and transverse stiffeners become increasingly engaged in load redistribution from the plastified web. Any hardening increase in shear resistance during the panel mechanism stage is modest in magnitude (up to ∼10% for some cases in this study) and is heavily dependent on the sizing of the flanges and stiffeners to carry redistributed forces.
KW - Second-order plate bending
KW - Shear mechanisms
KW - Slender steel plate girder
KW - Tension field action
KW - Ultimate shear resistance
KW - Web shear buckling
UR - http://www.scopus.com/inward/record.url?scp=85145979939&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85145979939&partnerID=8YFLogxK
U2 - 10.1016/j.tws.2022.110481
DO - 10.1016/j.tws.2022.110481
M3 - Article
AN - SCOPUS:85145979939
SN - 0263-8231
VL - 184
JO - Thin-Walled Structures
JF - Thin-Walled Structures
M1 - 110481
ER -