PSI - Issue 52

Haseung Lee et al. / Procedia Structural Integrity 52 (2024) 252–258 Haseung Lee, Hyunbum Park / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 1. Finite element models (a) ASTM D3090:Tensile strength test.; (b) ASTM D6641:Comporessive strength test.

In the case of Void, analysis was conducted in two cases: Intra Void and Inter Void. In order to determine the effect of the internal void on material properties, calculations were made by creating five different RVE models using longitudinal tension and compression, transverse tension and compression, and in-plane shear. The analysis method of Inter Void is similar to that of Intra Void, but additional ply and interface properties must be considered, and calculation must be done by considering 5 ply properties and 2 interface properties in normal and shear mode. Digimat could set the void count and void fraction of inter and intra, and this leads to enable prediction of the void volume and diameter in the RVE model. To determine the material property change by the void size, the material property change was determined by the void diameter of 200 ~ 400 μ m based on void fraction of 5 %. As the figure below, it shows as the knockdown factor with considering the case of no void as 100% basis.

Fig. 2. Analysis result of specimen applied with void.

Fig. 3. Material properties depending on the diameter of the intra void at void fraction 5% (a) Strength.; (b) Stiffness