Nonlinear magnetohydrodynamics of footpoint-driven coronal loops

Results are presented from magnetohydrodynamic (MHD) simulations of the phase-mixing and resonant absorption of standing torsional Alfven waves generated by motion at the footpoint of a line-tied coronal loop with axial symmetry. The high wave amplitudes that develop in the resonant layer cause nonlinear effects and the driven coronal loop does not evolve to a stationary state in contrast to linear MHD results. The energetics of a monochromatically driven coronal loop show that resonant heating can be very efficient even in the absence of global modes.