Dynamic analysis by FEM for a measurement system to observe viscoelasticity using levitation mass method

摘要

Dynamic analysis was carried out for a novel measurement system to obtain material viscoelasticity using the levitation mass method [Fujii and Yamaguchi, Rev Sci Instrum 75-71:119-12.3, 2004; Yamaguchi et al., Mech Syst Signal Process 20:1905-1922, 2006; Fujii and Yamaguchi, J Mater Sci 40-18:4785-4790, 2005], which was proposed by Fujii. For this measurement system, a viscoelastic specimen is attached to a block, which is levitated due to a pneumatic linear bearing. Impact load is applied to the levitated block, and then the movement of the block is measured by a laser interferometer. By following our proposed numerical procedure using nonlinear finite element method in our previous paper [Yamaguchi et al., Mech Syst Signal Process 20:1905-1922, 2006], the dynamic properties of the measurement system were investigated. Time histories of velocity for the block were simulated. These results were compared with experimental results. Furthermore, undesirable dynamic components for the measurement system were evaluated using the numerical model by varying pulse width of the input load.