PSI - Issue 28

Saiaf Bin Rayhan et al. / Procedia Structural Integrity 28 (2020) 1901–1908 Author name / Structural Integrity Procedia 00 (2019) 000–000

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set. A further discussion on the periodic and non-periodic boundary conditions can be found in Ansys Material Designer user guide (Ansys (2018)). A. B.

Figure 3: A: RVE meshing; B: Plate meshing with boundary conditions

For the buckling load case studies, a quadrilateral mapped shell element is chosen, Fig. 3 (B). An optimum number of mesh element is set to 5049 while additional elements would only result in higher computation time without any noticeable changes in critical buckling outcomes. As specified earlier, unit load is uniformly distributed on the nodes of the top edge (shorter side) which is simply supported while the opposite edge is completely restrained. Furthermore, the longer edges are kept free.

5. Parametric results discussion 5.1. Effect of fiber volume fraction

At first, studies are carried out to investigate the effect of increasing the fiber volume fraction on the critical buckling load of the woven composite plate, Fig. 4 (A). From the illustration, it is apparent that as the fiber volume fraction increases, for both the weave and twill type woven composite plates, the critical buckling value increases significantly. For instance, increasing the fiber volume fraction from 0.4 to 0.5, results in the increase of the buckling load of the twill type and plain type by 22.8% and 21.5% respectively. Another crucial finding is that in comparison with the plain woven composite, twill woven demonstrates around 3% to 7% higher buckling load achievability. 5.2. Effect of yarn fiber volume fraction Unlike the previous case study, increment of the yarn fiber volume fraction has an adverse effect on the critical buckling load of the woven composite plates, Fig. 4 (B). For both twill and plain cases, a linear relationship between the critical buckling load and the fiber volume fraction is established and it is found that a raise of 1% yarn fiber volume fraction will reduce the critical buckling load capacity of the plates by approximately 1%. 5.3. Effect of fabric thickness An interesting phenomenon is observed while investigating the critical buckling load of the woven composite plate against the change of fabric thickness, Fig. 4 (C). It is found that despite the increment of the fabric thickness, the buckling capability of the plates made of weave and twill type woven composite does not vary significantly. For instance, increasing the fabric thickness from 0.208 mm to 0.216 mm would reduce the critical buckling predictions of the woven and twill type plates only by 0.8% and 1% respectively.