(a) Graded array of asymmetric resonators with linearly increasing lengths. The spatial modification of the resonant frequency of the resonators allows to obtain locking in different spatial positions depending on frequency. (b) Space-time waterfall plots illustrating the vertical displacement (flexural) and the rotation (torsional) along the waveguide. The array of elements is highlighted with a red box. The numerical simulations are performed for a configuration with an array of (I) 9 resonators, (II) 25 resonators, and (III) 50 pairs of graded resonators. The torsional and flexural waves represented in the diagrams are normalized by the same amplitude coefficient. By increasing the number of graded resonators, i.e from left to right, it is possible to move from locking to genuine rainbow trapping.