Global sensitivity analysis of backside coating parameters on dynamic response of AM-AFM
Keywords:AM-AFM, Global sensitivity analysis, Nonlinear vibration, Coated cantilever, Backside Coating parameters, Timoshenko beam theory
Influence of backside coating parameters on dynamic response of AM-AFM is modeled. Timoshenko based beam model is used and the general nonlinear interaction force is enclosed. The coupled ODEs of motion are achieved. The mode shapes are determined for coated cantilever and the natural frequency of each mode is validated with experimental results. It is showed a shorter cantilever with tip mass have better accuracy and inelastic and massless assumptions are not proper choice for modelling of the coating. The assumed mode method is used to determine time response of system for faraway and scanning condition of AM-AFM. Amplitude of response is calculated by FFT of time domain. Sensitivity indices of backside coating parameters are determined based on Sobol method in their physical range. It is showed the sequence of indices remains unchanged. The most important parameters and interactions on output variance are introduced. The results are concluded.