Sensitivity reanalysis of vibration problem using combined approximations method

Sensitivity is indispensable to structural modification and optimization. This paper focuses on the analytical sensitivity reanalysis for vibration problem in the framework of combined approximations (CA) method. The sensitivity reanalysis formulations of eigenvalues and eigenvectors are derived from the vibration equation reduced by CA method, where the eigenvector sensitivity is solved by Nelson's method. Numerical examples demonstrate the accuracy and efficiency of the proposed reanalysis method. Especially, this method can greatly improve the efficiency of sensitivity analysis and can accelerate the gradient-based structural optimization constrained with frequencies and modal shapes.