Session: 30-05 Modeling, algorithms and computational techniques II

Paper Number: 82413

82413 - A Linearization Method Based on 3D Contact Model for the Steady-State Analysis Towards Complex Engineering Structures Containing Friction 

In last decade, the multi-harmonic balance method (MHBM) has become the mainstream algorithm to calculate the steady-state response of dry friction systems. Most harmonic balance based methods applicable for engineering structures adopt two decoupled orthogonal Jenkins elements to approximate the constitutive relation on the contact interface because it is hard to derive analytically the Jacobian matrix for 3D contact model. Although the computational efficiency is guaranteed, the relationship between the frictional force and the relative displacement deviates from the real situation especially when the trajectory on the contact surface is not a straight line. In this case, the accuracy gain by capturing higher-order harmonics is far less than the accuracy loss from the inaccurate contact models. In addition, such methods generally use commercial finite element software for pre-processing, and execute nonlinear iterative solving process through the in-house code. Therefore, only the displacement response of the structure will be obtained, but the stress which is more concerned by engineers cannot be given.

In this paper, a linearization method based on 3D contact model for the steady-state response analysis of dry friction systems is proposed from the perspective of engineering application. The core is to equivalently express the nonlinear force represented by the 3D contact model into distributed local linear damping and stiffness by means of linearization, and apply it to the finite element model of linear substructures with MATRIX 27 elements. In this way, the steady-state response can be calculated in ANSYS. The 3D contact model ensures the accuracy of the algorithm, and the linearization improves the efficiency. Besides, the stress can be directly displayed in ANSYS post-processing. A real multi-stage stator casing with a friction ring damper is taken as an example to illustrate the effectiveness and efficiency of the proposed method. Results show that for this finite element model with 1944 nonlinear degrees of freedom, the average calculation time for one frequency is less than 10 s. The larger the scale of the model, the greater the benefit of efficiency.

Presenting Author: Yaguang WU Beihang University

Presenting Author Biography: Post-doc, School of Energy &amp; Power Engineering, Beihang University<br/>Research interests:<br/>1) Piezoelectric based technologies for vibration and noise reduction; <br/>2) Nonlinear dynamics of dry friction systems.

Authors:

Fucai Xiao Beihang University
Lin Li Beihang University
Yaguang WU Beihang University
Yu Fan Beihang University
Hui Zhang AECC Commercial Aircraft Co., Ltd.