PSI - Issue 70

P. Saravana Kumar et al. / Procedia Structural Integrity 70 (2025) 43–50

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3. Experimental Investigation 3.1 Static Behavior of Steel Beams

3.1.1 Loading and Load Deflection Behavior Three sets of steel beams were subjected to gradually increasing load applied as center of the span. The deflection readings were taken as some fixed intervals of loading and the load deflection values are calculated. Since the load is continually applied concentrated load, strength of material principles the theoretical deflection were calculated as =w 3 /48 plotted on the same Fig. 3.

Fig. 3. Load vs Deflection for (a) ISMB 200; (b) ISMB 125; (c) ISMB 100.

3.1.2 Stiffness Characteristics Stiffness is defined as the load required to cause unit displacement or rotation. The stiffness of the beams is calculated by plotting the load deflection graphs of each specimen. A tangent is drawn and the slope of the tangent is calculated which gives the stiffness of the beam.

Table 2. Stiffness of the beams.

Specimen ISMB 200 ISMB 125 ISMB 100

Stiffness (kN/mm)

55 50

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