MEMS based acoustic thermomechanical characterization of aluminum 6061-T651 beams

Abstract

Temperature-based testing is an important tool in determining the mechanical characteristics of structures. Metallic structures, such as aluminum beams, respond to temperature variations. Similarly, Young’s modulus of elasticity of the material has a temperature dependence that contributes significantly to the overall mechanical qualities of the material. In this work, a method based on flexural frequency response is described in which the variation in the experimental 5th natural frequency under thermal loading is employed to extract the coefficient of thermal dependence of Young’s modulus. This coefficient is then employed in the theoretical model to validate the experimental 2nd, 3rd, 4th and 5th natural frequencies of the aluminum beam. A micro-electro-mechanical-systems based microphone is used to monitor the frequency response of the beam. Constant geometry and constant elasticity models are presented and compared. The proposed method is applied to an aluminum 6061-T651 beam. Experimental results are in good agreement with the theory.