Issue 74

E. Sharaf et alii, Fracture and Structural Integrity, 74 (2025) 262-293; DOI: 10.3221/IGF-ESIS.74.17

with code requirements, using a value of 2.0 kN/m². For seismic combination, a smaller portion of the live load (typically 25% or according to code) was included with the mass for dynamic analysis. The seismic lateral forces were applied in the present study through the response spectrum analysis (RSA) method. A code based design response spectrum was applied, taking into account parameters that include site class, seismic zone, importance factor, and structural damping ratio (assumed to be 5% for reinforced concrete frames).

V ALIDATION OF THE PROPOSED EQUATION

Overview of validation methodology n this study, a number of examples are presented to assess the validity of the suggested equation to estimate buildings' fundamental period. Initially, two cases of moment-resisting frame (MRF) structures of reinforced concrete with uniform cross sections are investigated. Then, applying more models with varying section properties along their height. The fundamental periods derived from the suggested equation are compared with numerical model eigenvalue analysis solutions, which represent the benchmark solution. Comparisons are made using ETABS 2018 and MATLAB 2023 [38, 39] for reliability and accuracy. Estimation of the fundamental period for a six-story reinforced concrete frame with uniform member sections The following frame consists of six levels, each with a height of 3 meters and a span of 6 meters. The sections of both beams and columns are uniform throughout the building's entire height, as shown in Fig. 8 and Tab.1. This example was solved using the proposed method by first determining the equivalent lateral stiffness and then computing the mass transfer coefficient from one floor to the level of the next. This method is carried out in five iterations. The result of applying the proposed method is compared with the values from FEM as shown in Tab. 2. I

Figure 8 : Configuration of reinforced concrete MRF.

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