3D Dynamic Analysis of a 270m Concrete Faced Rockfill Dam

2011 ◽  
Vol 287-290 ◽  
pp. 3131-3134
Author(s):  
Da Wei Sun ◽  
Kang Ping Wang ◽  
Guo Dong Zhang ◽  
Hui Qin Yao
Keyword(s):  
Permanent Deformation ◽  
Linearization Method ◽  
Equivalent Linearization ◽  
Element Mesh ◽  
Maximum Acceleration ◽  
Rockfill Dam ◽  
Calculation Results ◽  
Equivalent Linearization Method ◽  
Strain Model ◽  
Maximum Horizontal Acceleration

3D finite element mesh for a 270m high CFRD was generated with advanced grid discretion technology. Adopting EI-Centro seismic wave with maximum horizontal acceleration 0.277g, dynamic response of this 270m high concrete faced rockfill dam was obtained by equivalent linearization method. Using residual strain model, the permanent deformation of the dam was obtained. Calculation results showed that the maximum acceleration and displacement of dam body, dynamic stress of face slab and deformation of joints are all within normal range. Therefore, the safety of dam would be guaranteed when it is subjected to 7 degree earthquake.

Equivalent Linearization of Bladed Disk Assemblies with Friction Nonlinearities Under Random Excitation

2020 ◽  
Author(s):  
Alwin Förster ◽  
Lars Panning-von Scheidt ◽  
Jörg Wallaschek
Keyword(s):  
Degrees Of Freedom ◽  
Turbine Blades ◽  
Random Excitation ◽  
Linearization Method ◽  
Equivalent Linearization ◽  
Friction Damper ◽  
Bladed Disk ◽  
Stationary Stochastic Processes ◽  
Bladed Disk Assembly ◽  
Equivalent Linearization Method

Abstract The present article addresses the vibrational behaviour of bladed disk assemblies with nonlinear shroud coupling under random excitation. In order to increase the service life and safety of turbine blades, intense calculations are carried out to predict the vibrational behaviour. The use of friction dampers for energy dissipation and suppression of large amplitudes makes the mechanical system nonlinear, which complicates the calculations. Depending on the stage, different types of excitation can occur in a turbine, from clearly defined deterministic to random excitation. So far, the latter problem has only been dealt with to a limited extent in the literature on turbomachinery. Nevertheless, there are in general different approaches and methods to address this problem most of which are strongly restricted with regard to the number of degrees of freedom. The focus of this paper is the application of an equivalent linearization method to calculate the stochastic response of an academic model of a bladed disk assembly under random excitation. The nonlinear contact is modelled both with an elastic Coulomb-slider and a Bouc-Wen formulation to reproduce the hysteretic character of a friction nonlinearity occurring in the presence of a friction damper. Both the excitation and the response are limited to mean-free, stationary stochastic processes, which means that the stochastic moments, do not change over time. Unlike previous papers on this topic, the calculations are performed on a full bladed disk assembly in which each segment is approximated with several degrees of freedom.

Sign in / Sign up

Export Citation Format

Share Document