Journal of Theoretical
and Applied Mechanics

56, 4, pp. 1043-1053, Warsaw 2018
DOI: 10.15632/jtam-pl.56.4.1043

Assessment of the strength reduction factor in predicting the flexural strength

Sema Alacali, Guray Arslan
In the design of flexural strength, the strength reduction factor decreases from tension-
-controlled sections to compression-controlled sections to increase safety with decreasing
ductility. This paper presents how to determine the reduction factor for flexural strength
of reinforced concrete beams according to ACI code. In the reliability-based design, the
reliable prediction of the flexural strength of reinforced concrete members is assured by the
use of reduction factors corresponding to different target reliability index . In this study,
for different and coefficients of variation of the flexural strength parameters, the flexural
strength reduction factor has been investigated by using experimental studies available in
the literature. In the reliability analysis part of the study, the first-order second moment
approach (FOSM) has been used to determine the reduction factor. It has also been assumed
that the random variables are statistically independent.
Keywords: reinforced concrete, beam, flexure strength, reduction factor, target reliability

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