Harmonic Balance Method for the stationary response of continuous systems with nonlinear hysteretic damping under harmonic excitation

Under harmonic excitation, soil exhibits softening behaviour that can be captured through the so-called hyperbolic soil model. The response of systems with such a material model can elegantly be obtained using the classical Harmonic Balance Method (HBM). Soil also exhibits nonlinear hysteretic damping under harmonic excitation, feature which is not incorporated in the hyperbolic soil model. The response of a system that includes also the nonlinear hysteretic damping cannot be obtained using the classical HBM. This work demonstrates the application of an advanced HBM (more specifically, alternating frequency-time HBM) for finite and infinite systems that exhibit softening behaviour and nonlinear hysteretic damping. The purpose of this model is to, in the future, investigate the influence of the nonlinear hysteretic damping on the response of such systems, as opposed to linear viscous or hysteretic damping that is usually adopted. To conclude, we show that the advanced HBM is an effective tool for revealing fundamental characteristics of continuous systems with softening behaviour and nonlinear hysteretic damping whose stationary responses consist of either standing or propagating waves.