Numerical optimisation of a classical stochastic system for targeted energy transfer

•The paper presents a study of target energy transfer (TET) phenomenon in stochastic system•The paper proposes to use a surrogate optimisation algorithm to optimise the TET performance by selecting optimal values of the system parameters•The obtained numerical results indicate that the efficiency of a nonlinear energy sink can be 18% for noise intensity values well below the accepted threshold value. The paper studies stochastic dynamics of a two-degree-of-freedom system, where a primary linear system is connected to a nonlinear energy sink with cubic stiffness nonlinearity and viscous damping. While the primary mass is subjected to a zero-mean Gaussian white noise excitation, the main objective of this study is to maximise the efficiency of the targeted energy transfer in the system. A surrogate optimisation algorithm is proposed for this purpose and adopted for the stochastic framework. The optimisations are conducted separately for the nonlinear stiffness coefficient alone as well as for both the nonlinear stiffness and damping coefficients together. Three different optimisation cost functions, based on either energy of the system’s components or the dissipated energy, are considered. The results demonstrate some clear trends in values of the nonlinear energy sink coefficients and show the effect of different cost functions on the optimal values of the nonlinear system’s coefficients.