Investigation into the influence of the Mullins effect on the dynamic behavior of hybrid laminates

The benefits of fiber metal laminates have been widely studied and exploited in numerous applications. However, due to their high stiffness and low weight, these laminates can exhibit an undesirable dynamic behavior when subjected to vibrations. To overcome this, hybrid laminates containing an elastomeric damping layer, such as hybrid carbon fiber reinforced polymer elastomer metal laminates (HyCEML) have been developed and found to significantly improve the dynamic behavior of such laminates as shown by Sessner et al. [1]. The key mechanism behind this high damping capability is commonly referred to as constrained-layer damping, first published by Kerwin [2]. In constrained-layer damping laminates, the elastomer layers undergo large deformations due to their comparably low stiffness. This motivates the consideration of large strain phenomena commonly found in elastomers even when global laminate deformations are small, as in linear dynamic analysis. This work specifically addresses the cyclic softening of elastomers, commonly known as Mullins effect [3]. The study aims at the experimental characterization of said Mullins effect and its constitutive modeling in order to elaborate its influence on the constrained-layer damping mechanism. ... mehrCyclic uniaxial and planar tension tests are conducted to determine the elastomer’s hyperelastic response and damage due to the Mullins effect. The influence of the Mullins effect on the laminates’ damping characteristics is then analyzed numerically by comparing the resulting loss factors of undamaged and damaged laminates in finite element models. The Mullins effect of the elastomer layers is modeled using adapted constitutive relations proposed by Ogden and Roxburgh [4] as well as Dorfmann and Ogden [5]. This study shows a clear dependence of the constrained-layer damping on previous damage due to the Mullins effect, which is captured well by the chosen models.

References:
[1] Sessner, V., Jackstadt, A., Liebig, W.V., K¨arger, L., Weidenmann, K.A., ”Damping Characterization
of Hybrid Carbon Fiber Elastomer Metal Laminates using Experimental and Numerical
Dynamic Mechanical Analysis”. Journal of Composites Science, Vol. 3, No. 1, pp 3 (2019).
[2] Kerwin, E.M., ”Damping of FlexuralWaves by a Constrained Viscoelastic Layer”, The Journal
of the Acoustical Society of America, Vol. 31, No. 7, pp 952–962 (1959).
[3] Mullins, L., Tobin, N.R., ”Stress softening in rubber vulcanizates. Part I. Use of a strain amplification
factor to describe the elastic behavior of filler-reinforced vulcanized rubber”, Journal
of Applied Polymer Science, Vol. 9, No. 9, pp 2993–3009 (1965).
[4] Ogden, R.W., Roxburgh, D.G., ”A pseudo–elastic model for the Mullins effect in filled rubber”,
Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering
Sciences, Vol. 455, No. 1988, pp 2861–2877 (1999).
[5] Dorfmann, A., Ogden, R.W., ”A constitutive model for the Mullins effect with permanent set in
particle-reinforced rubber”, International Journal of Solids and Structures, Vol. 41, No. 7, pp
1855–1878 (2004).