Damping Characterization of Hybrid Carbon Fiber Elastomer Metal Laminates using Experimental and Numerical Dynamic Mechanical Analysis

摘要

Lightweight structures which consist to a large extent of carbon fiber reinforced plastics(CFRP), often lack sufficient damping behavior. This also applies to hybrid laminates such asfiber metal laminates made of CFRP and aluminum. Since they are usually prone to vibrationsdue to their high stiffness and low mass, additional damping material is required to meet noise,vibration and harshness comfort demands in automotive or aviation industry. In the present study,hybrid carbon fiber elastomer metal laminates (HyCEML) are investigated which are intended toinfluence the damping behavior of the laminates by an elastomer interlayer between the CFRPply and the aluminum sheets. The damping behavior is based on the principle of constrainedlayer damping. To characterize the damping behavior, dynamic mechanical analyses (DMA) areperformed under tension on the elastomer and the CFRP, and under three point bending onthe hybrid laminate. Different laminate lay-ups, with and without elastomer, and two differentelastomer types are examined. The temperature and frequency dependent damping behavior isrelated to the bending stiffness and master curves are generated by using the time temperaturesuperposition to analyze the damping behavior at higher frequencies. A numerical model is built upon the basis of DMA experiments on the constituents and micro mechanical studies. Subsequently,three point bending DMA experiments on hybrids are simulated and the results are compared with theexperimental investigations. In addition, a parameter study on different lay-ups is done numerically.Increasing vibration damping is correlated to increasing elastomer content and decreasing elastomermodulus in the laminate. A rule of mixture is used to estimate the laminate loss factor for varyingelastomer content.