Calculation of the Modulus of Elasticity with Using Natural Frequency Formula and Updated Finite Element Analysis Of Automotive Rear Lamp Lens

Abstract

In this study; the weight of the modal accelerometer used in the Roving Hammer Impact Test Method was added in the finite element analysis (FEA) and the undamped modal analysis of the automotive rear lamp lenses were performed. Also, calculated new Elastic Modulus for Polymethylmethacrylate (PMMA) material with using natural frequency formula and this value was used in the ANSYS WB program and the undamped modal analysis was repeated. After that, frequency response functions (FRFs) of an automotive rear lamp lens were obtained by using Roving Hammer Impact Test Method. At the same time; dynamic characteristics of the structure, natural frequencies, damping ratios and mode shapes were obtained. Damping ratios were calculated from the FRF’s by using the Half Power Method. Finally, experimental modal analysis (EMA) and FEA results were compared.

Modal Analysis of Lenses Used in Automotive Lighting Industry and Obtaining MAC Matrix

“…Damping ratios were calculated from the FRF's by using the Half Power Method. Finally, experimental modal analysis (EMA) and FEA results were compared [5].…”