A convenient method was developed to estimate the tangential contact stiffness between dry friction dampers using the general finite element method(FEM) software.The influences of various parameters such as normal preload

friction coefficient

damper material properties and the radius of the cylinder damper etc on the contact stiffness were investigated in detail.The results show that

the contact stiffness improves with increase in these parameters.A formula of calculating the tangential contact stiffness for variable normal preload was obtained by fitting the results

making it more conveniently to take into account the variety of contact stiffness in calculating the nonlinear response of shrouded blade instantaneously.Eventually

influences of the contact stiffness on the shrouded blade nonlinear response were studied with the formula

the results indicate that

the resonant frequency of the blade increase and the peak amplitude decrease gradually with increase in the contact stiffness

and all of which are close to a fixed value respectively.