PSI - Issue 2_B

F.Sacchetti et al. / Procedia Structural Integrity 2 (2016) 245–252 251 F.Sacchetti, W.J.B. Grouve, L.L. Warnet, I. Fernandez Villegas/ Structural Integrity Procedia 00 (2016) 000 – 000 7

Figure 8: Micrograph of the surface after peeling in which the crack propagation is from left to right as shown in the arrow. The beach marks are clearly visible as light and dark bands. Right) 10x magnification. Left) A magnified view of the encircled area.

4. Conclusion

The feasibility of the mandrel peel test to characterize the fracture toughness of woven fabric reinforced thermoplastic composites was studied by comparing it to the standardized DCB test. The mandrel peel test can be considered to be an easy and fast test compared to the DCB test. Both testing techniques yielded similar fracture toughness values and have shown similar stick slip behavior. However, the mandrel used in the peel test limited the unstable crack propagation distance. Consequently, a single mandrel peel test has produced more than 20 times the amount of data points per unit crack length than the DCB test. Hence, the mandrel peel test can be considered to be more statistically relevant than DCB test. Nevertheless, this is in contradiction with the slightly higher standard deviation observed in the mandrel peel test with respect to the DBC test. The mandrel peel test seems to be a good alternative to the DCB test for woven fabric reinforced composites. However, further research is required to understand the effect of mode mixity, internal stresses in the sample, and test parameters on the measured results of the mandrel peel test.

Acknowledgements

This project is funded by and performed at the Thermoplastic Composites Research Center (TPRC). The support of the Region Twente and the Gelderland & Overijssel team for the TPRC, by means of the GO Programme EFRO 2007-2015, is gratefully acknowledged.

References

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