Harmonic Balance Vibration Analysis of Turbine Blades With Friction Dampers

Abstract

Although considerable effort has been devoted to the formulation of predictive models of friction damper behavior in turbomachinery applications, especially for turbine blades, the problem is far from being solved due to the complex nonlinear behavior of the contact surfaces. This paper primarily focuses on analytical and numerical aspects of the problem and addresses the problem in the frequency domain while exploring the viability of equivalent time-domain alternatives. The distinct features of this work are: (i) the modelling of nonlinear friction damper behavior as an equivalent amplitude-dependent complex stiffness via a first-order harmonic balance method (HBM), (ii) the use of sine sweep excitation in time-marching analysis, (iii) the application of the methodology to numerical test cases, including an idealised 3D turbine blade model with several friction dampers, (iv) the verification of the numerical findings using experimental data, and (v) a detailed assessment of the suitability of HBM for the analysis of structures with friction dampers.

A dynamic Lagrangian frequency–time method for the vibration of dry-friction-damped systems

“…In most studies performed to date, the friction damper models considered have been simple enough that the damper itself can be included in the contact element, with the linear springs then representing the damper's flexibility, thereby eliminating the need to represent the damper as a separate structure. For instance, one-directional springs are routinely included in contact elements in order to capture the flexibility of one-dimensional dampers [9][10][11][12][13].…”

Qualitative analysis of forced response of blisks with friction ring dampers

“…This method is found to be efficient and was widely used, in the past, to study friction dampers in bladed disks assemblies or shroud contacts. Some examples have been presented by Wang and Chen (1993), Sanliturk et al (1997) and Yang and Menq (1997) for mono-harmonic vibrations and by Pierre et al (1985), Petrov and Ewins (2003), Nacivet et al (2003), and Guillen and Pierre (1999) for multi-harmonic vibrations.…”

Numerical and Experimental Study of Friction Damping Blade Attachments of Rotating Bladed Disks

“…The relative displacements in the tangential directions are of very small amplitude and a microslip behavior is expected. Microslip models have already been used in the analysis of blades with friction dampers (Menq et al [14], Sanliturk et al [15]), but such models are not applicable in the case of blade root friction because the normal loads are not known in advance. The first numerical studies devoted to the effects of root friction on the forced response of blades have been published recently (Charleux et al [16], Petrov and Ewins [17]).…”