An attempt to improve reliability of loss factor measurement and evaluation of attenuation performance for laminated metallic materials

Abstract

To improve the reliability of the loss factor identification technique for metallic alloys proposed by the authors using a slender beam and s-dB bandwidth method, this study first investigates the effects by the fixing conditions of the specimen, such as tightening torque and installing shims. According to the test results, tightening torque variations and inserting shims affect little on the loss factor. Loss factors of two different laminated metallic alloys were then measured under several heat treatment conditions. Some shape changes (warp) were observed at some heat treatment temperature, so numerical calculations using finite element analysis were carried out to check the change of obtained loss factor by the s-dB bandwidth method due to the warp. The numerical results have suggested that the warp about 15 mm versus beam length 500 mm doesn't affect substantially on the loss factor.