Bender elements (BE) have been widely utilized to measure shear wave velocities at low shear strain. One of the most controversial issues is the lack of knowledge of the actual behaviour of the BE inside the soil. BE tests were compared with resonant-column tests and readings of miniature accelerometers inside the specimen at different elevations. While time domain (TD) analysis produced reasonable results, frequency domain (FD) analysis showed significant differences. Experimental measurements and simplified numerical simulations revealed the existence of several peaks in the transfer function between BE. These peaks produce slight variations in the slope of the phase angle function, affecting the travel time estimation. FD analysis should be done in a frequency range located far away to the main peaks, requiring a careful selection of the input signal depending of the soil stiffness, characteristics of BE and specimen dimensions.
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