Title:
Plastic Hinge Lengths in High-Rise Concrete Shear Walls
Author(s):
Alfredo Bohl and Perry Adebar
Publication:
Structural Journal
Volume:
108
Issue:
2
Appears on pages(s):
148-157
Keywords:
concrete walls; cracking; displacement; finite element method; flexure; inelastic curvature; nonlinear analysis; plastic hinge; rotation; seismic design; shear walls
DOI:
10.14359/51664249
Date:
3/1/2011
Abstract:
It is commonly assumed that the maximum inelastic curvature in a wall is uniform over a plastic hinge length (height) lp equal to between 0.5 and 1.0 times the wall length lw (horizontal dimension). Experimental and analytical results indicate that inelastic curvatures actually vary linearly in walls; however, the concept of maximum inelastic curvature over lp can still be used to estimate the flexural displacements of isolated walls. Based on the results of nonlinear finite element analyses using a model validated by test results, an expression is proposed for lp as a function of wall length, moment-shear ratio, and axial compression. A procedure to account for the influence of applied shear stress on lp is also presented. In high-rise buildings, walls are interconnected by numerous floor slabs, resulting in a complex interaction between walls with different lw. Longer walls generally have larger shear deformations near the base because their higher relative flexural stiffness and flexural strength attracts a larger portion of the total shear force. More slender walls correspondingly have larger flexural deformations near the base to maintain compatibility of total deformations at the floor levels. An expression is presented for estimating maximum curvatures in systems of walls with different lp where the actual linear variation of inelastic curvatures must be accounted for.