Sensitivity analysis of forced response for nonlinear structures with friction and gaps

An effective method is proposed to calculate sensitivities of the forced response to parameters of the contact interfaces for structures with strongly nonlinear interactions such as friction contact interfaces, gaps and interferences. The sensitivity analysis is performed in frequency domain simultaneously with the forced response calculations. First and second order sensitivity coefficients are determined with respect to friction coefficients, gaps, contact stiffness coefficients and other parameters of contact interfaces. Analytical expressions are derived for the sensitivity characteristics of the contact interfaces which provide exact and extremely fast calculations. Numerical investigations of the sensitivity of the multiharmonic steady-state forced response of structures with friction contacts and gaps have been performed illustrating the capabilities and efficiency of the method proposed.