PSI - Issue 42

Stefan Sieberer et al. / Procedia Structural Integrity 42 (2022) 72–79 S. Sieberer et al. / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 5. Strain at the shaft and at neck and eye for Specimen 1 (left) and Specimen 2 (right).

Fig. 6. Strain concentration factors at the shaft and at neck and eye for Specimen 1 (left) and Specimen 2 (right).

Fig. 7. Vertical displacement of the eye over load to give bearing sti ff ness of the specimens.

influence is visible. This nonlinearity at higher loads is potentially from layer debonding or single fibre bundle failure and will be further investigated. Figure 7 shows the load over the vertical displacement of the specimens at the eye. This represents the compression of the top of the part and some tensile strain under the load, and results in a visual gap at the top of the eye to the bolt. Because the strain of the fibres is low, below 0.01 at rupture, the compression under the bold is the main contribution to this bearing compliance. Table 2 gives calculated bearing sti ff ness values, obtained as a chord sti ff ness between 10% and 50 % of the part strength. In comparison of the two material layup strategies, the bearing sti ff ness ratio is 9.9 / 8.3 = 1.19, which is a lower gain than in the fibre-dominant part strength and tensile sti ff ness. The increase in the sti ff ness is attributed to reduced void content from denser fibre placement and growing micromechanical interaction of fibres in transverse compression at higher φ .