ACI says the principal tensile strength of cracked concrete is not well defined in existing models for predicting the shear response of reinforced concrete (RC) membrane elements. As a result, the shear strength of RC elements is generally overestimated due to the unrealistic decreasing slope of tensile stress as the crack accumulates
The paper, Effect of Limited Tension Stiffening on Behavior of Reinforced Concrete Panels in Shear, says the investigation was carried out by proposing an analytical model named as the tension-stiffening fixed-angle truss model (TFTM).
According to ACI: “The proposed model includes the limited tension-stiffening effect of post-cracking reinforced concrete and adopts the fixed-angle theory.”
In the analysis of TFTM, an iterative root-finding technique and a search method genetic algorithm are applied for solving the stress-strain relationship. The limited tension-stiffening effect on RC panels is examined with a series of tests.
“Predictions by the proposed model show very good agreement with experimental results, and the elapsed time for each calculation loop is reduced significantly,” ACI adds.
This paper was written by Xueying Wang and J. S. Kuang.