Optimal Design of Constrained-Layer Damping Considering Variability in Material and Operational Condition

Abstract

Surface damping treatment is an easy way to reduce noise and vibration of structures. The damping performance of surface treatment needs to be robust and reliable against variability in damping materials and operational temperature. In this paper, a new approach is proposed to optimize the constrained-layer damping structure while considering the variability in viscoelastic damping material properties and operational temperature. The variability in viscoelastic damping material properties is characterized based on the fractional-derivative model and test data in a statistical manner. Significant variability is also found in the dynamic responses of the damping material due to operational temperature change. Such variability is also statistically identified and taken into account in the design process. Three different design objectives drive three different optimization formulations. Based on three formulations, this study explores both deterministic and reliability-based optimal designs for the constrained-layer damping layout. The eigenvector dimension reduction (EDR) method is used for reliability analysis. The results of reliability analysis show that the EDR method can effectively characterize the variability in the dynamic responses of the damping material. Consequently, the reliability-based optimization formulation gives more robust and reliable damping layout design amidst the variability in viscoelastic damping material properties and operational temperature.