Microdamage, Viscoelasticity and Viscoplasticity as Main Phenomena in Thermal Stress Relaxation in Laminated Composites

Abstract:

Microdamage, viscoplastic and viscoelastic strain development in 90-layers of cross-ply laminates subjected to tensile loading is studied on unsymmetrical GF/EP laminates measuring the thermal curvature change. All three phenomena partially compensate for the effect of the thermal mismatch reducing the residual stress (specimen curvature). The viscoplastic strain contribution to curvature change is the largest whereas the effect of transient viscoelasticity is the smallest. Damage is included in the analysis through its effect on the effective transverse modulus of the 90-layer.

• Periodical: Key Engineering Materials (Volume 713)
• Pages: 99-102
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.713.99
• Online since: September 2016
• Authors: Janis Varna*, Magnus Persson, Abdelghani Hajlane
• Keywords: Curvature, Damage, Laminate, Thermal Expansion, Viscoelasticity, Viscoplasticity

References

[1] Varna J., Key Engineering Materials, vols. 488-489 (2012), 490-493.

[2] Giannadakis K. and J. Varna, Composite: Part A, 62, (2014), 67-76.

[3] Varna J. and M. Loukil, Composite Materials, (2016), accepted.

[4] Pupurs A., J. Varna, M. Loukil, H. Ben Kahla, D. Mattsson, Composites Part A (2016), 244-252.

DOI: 10.1016/j.compositesa.2015.11.012

[5] Smith PA, Ogin SL., Compos Appl Sci Manuf 1999; 30: 1003-1008.