Local Stress Field Approach for Shear Failure Assessment of Reinforced Concrete Members

Abstract

Despite extensive research on behavior of reinforced concrete in shear, there is still considerable disagreement among researchers in proposing and using a rational way of calculating the shear strength of reinforced concrete members. Due to lack of a universally accepted model for shear, shear design provisions still generally consist of empirical relationships that differ from code-to-code. In this study, a simple rational formula for calculating the shear strength of reinforced concrete elements is proposed by conducting a systematic parametric study on the response of RC elements in shear. This is done by using a computational model which simulates the post cracking behavior of RC membrane element on the basis of local stress transferring mechanism between adjacent cracks and microscopic stress transfer across cracks. Through a comparison with extensive available experimental tests conducted on RC elements, it is shown that the proposed rational relation can appropriately predict the shear strength of reinforced concrete elements under different in-plane stress conditions. Then the proposed relation is extended to the shear design of RC members and again it is shown that the predicted shear strengths are in good agreement with the experimental test results under different combination of axial, bending and shear forces.

Micromechanical modeling of tension stiffening in FRP-strengthened concrete elements

“…The equilibrium of the local and average stresses in RC domain gives: 13) where and are the steel and the FRP local stresses at crack plane, respectively. Based on the compatibility relationships, the strains in the longitudinal direction (x-y coordinate system) can be expressed [25,52].…”

“…Based on the compatibility relationships, the strains in the longitudinal direction ( x–y coordinate system) can be expressed. 25,52…”

“…Based on the compatibility relationships, the strains in the longitudinal direction (x-y coordinate system) can be expressed. 25,52 The computational procedure for simulating the total tensile response of elements can be summarized as follows (Figure 9). It is initially assumed that the element is not cracked (n ¼ 0, n is number of cracks) and the average spacing between cracks is therefore equal to the element length (L c ¼ L).…”