Wide Scale Characterization and Modeling of the Vibration and Damping Behavior of CFRP-Elastomer-Metal Laminates—Comparison and Discussion of Different Test Setups

Abstract

The investigated hybrid carbon fiber reinforced plastics-elastomer-metal laminates (HyCEML) offer the potential of tailored structural materials with adaptable damping properties. Conventional fiber metal laminates, like glass laminate aluminum reinforced epoxy are already widely spread in the aviation industry owing to their outstanding fatigue behavior. By integrating an elastomeric interlayer, the glass fibers can be substituted by carbon fibers and damping properties of these laminates can be adjusted. The viscoelastic interlayer dissipates energy within the laminate by inducing shear strain during bending, which is commonly known as constrained layer damping. The aim of this paper is the description of the vibration and damping behavior of HyCEML over a wide temperature and frequency range by using different test methods. Dynamic mechanical analysis is used for the individual polymeric constituents and coupon specimens and modal analysis is used with different specimen geometries up to a component sized panel. In addition, analytical and numerical approaches complement the experiments and lead to a deeper understanding of the vibration and damping behavior. Owing to the high damping, already at frequencies of 5 kHz only running waves can be detected for the investigated panel size. The discussion of different test methods helps to identify material and wavelength dependent effects, but also possible adverse effects of certain methods.

Soft polymers dynamic characterisation using sandwich theory

“…where ρ l is the mass per unit length. In equation (34) the rotational inertia has been neglected. For the pinned-pinned boundary condition, the response is harmonic in space and time, thus, it can be defined an equivalent flexural stiffness B K that considers shear effects and satisfies the homogenised Euler-Bernoulli field equation…”

“…For example, Pelayo and López-Anelle 33 take the RKU model as reference to compare experimental and numerical results of multi-layered laminated glass beams. Also, Sessner et al 34 use the RKU model to analyse the modal damping behaviour of carbon-fibre-reinforced polymer (CFRP), elastomer and metal laminates. Other authors have developed more sophisticated models to analyse particular behaviours of CLD sandwich structures and use the RKU model to evaluate the performance of the developed models.…”

On the Influence of Low-Velocity Impact Damage on Constrained-Layer Damping in Hybrid Cfrp-Elastomer-Metal Laminates

“…The vibration characteristics of undamaged HyCEMLs have been studied experimentally by Sessner et al [5,8,9] and are complemented by simulations in [18,7], highlighting the influence of numerous lamination schemes as well as temperature and loading conditions. A comprehensive analytical modeling approach for vibrating heterogeneous laminates has been developed by Jackstadt et al [19][20][21].…”

An Experimental Approach for the Determination of the Mechanical Properties of Base-Excited Polymeric Specimens at Higher Frequency Modes

“…The dynamic-mechanical analysis (DMA) only covers a relatively low frequency range [1]. To overcome this drawback, a time-temperature superposition (Williams-Landel-Ferry equation) on a multi-frequency DMA measurement can be used [1][2][3]. For isotropic materials, ultrasonic immersion methods are particularly suitable [4,5].…”

“…In order to measure the vibration-damping properties at lower frequencies, a cantilever beam test specimen configuration is a standardized method according to ASTM E756-05 (2017). Therefore, the deformation of the specimen can be obtained among other techniques by means of a non-contact electromagnetic excitation [3,[10][11][12], the excitation due to the mechanical coupling to an electrodynamic shaker [13,14], or the loading due to the connection to two nylon wires [15]. Whereas the non-contact realization using an electromagnetic excitation suffered the drawback of a highly limited frequency range, the contacted approaches introduce an additional source of joint damping and are, therefore, more difficult to implement in thermal chambers.…”