PSI - Issue 70

Varsha S et al. / Procedia Structural Integrity 70 (2025) 51–58

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(SIFs) in a rectangular structural steel plate. Plate geometry was loaded with two necessary conditions: boundary constraints and external loading. As indicated on the left of the figure, all the four edges of the plate were completely clamped, termed as a CCCC boundary condition, which limits both translational and rotational motions along each edge. This imitates a rigidly fixed plate situation commonly found in structural applications like bridges, pressure vessels, and aircraft panels. On the other side, a downward static load of 5 N was applied at a specific point on the upper surface, along the negative Y-axis, to create tensile stresses near the crack front. This configuration provides a Mode I stress condition, which is very important in assessing crack opening behavior. The boundary and loading conditions applied play a significant role in the resulting SIFs and guarantee that the simulation closely resembles realistic operating conditions for early-stage fracture analysis.

2.2. Result and discussion

Fig. 2. Opening Mode (K1) plotted SIF vs crack growth length (mm)

As Fig.2 depicts the crack surfaces separate along directions that run perpendicular to the crack plane during the loading phase. Under this loading condition the normal stress acts across the crack surfaces and it is classified as the tensile or opening mode. A steadily increasing plot showcases that crack opening occurs in the section where the maximum stress intensity factor functions.

Fig. 3. Sliding Mode (K2) plotted SIF vs. crack growth length (mm)

The applied loading regimen in Fig.3 causes one crack surface to move in parallel with respect to the other surface along the crack plane. Under in-plane shear mode the deformation creates parallel motions between the crack surfaces while showing shear stress between them. The mechanism operates in an opposite manner to opening mode behavior.