An experimental study on transverse vibration of tapered bars in elasto-plastic regime

In the present study, the natural frequencies of axially loaded, tapered bars are obtained experimentally. A tensile load is applied gradually till failure (necking) starts at the minimum cross-section end or yielding initiates at the maximum cross-section end. Experiments are carried out for aluminum and mild steel specimens with four different taper ratios. The results are presented in the amplitude–frequency plane as waterfall diagrams, which are processed further using a suitable windowing technique to better resolve the first two vibration modes. A comparison of experimental observations with results obtained from ANSYS indicates agreement in the elastic part of loading, but the results differ in the post-elastic domain. It is believed that the present results can serve as benchmarks for further investigation in this domain.