Development of an Engine System Model for Predicting Structural Vibration

1995 ◽  
Author(s):  
S. H. Sung ◽  
D. J. Nefske
Keyword(s):  
Finite Element ◽  
Narrow Band ◽  
Vibration Response ◽  
System Model ◽  
Structural Vibration ◽  
Octave Band ◽  
Engine System ◽  
Excitation Frequencies ◽  
Engine Components ◽  
Structural Mass

Abstract A finite-element based engine system model is developed for predicting the structural vibration of the engine. The engine system model combines modal models of the major bolted-together sub-structures of the engine, with non-structural mass models of the remaining engine components added to bring the inertial properties to those of the running engine. The model is developed and experimentally evaluated with impact and shaker excitation tests. Comparisons are made of the predicted and measured vibration response for various partially assembled engine configurations, as well as for the fully assembled engine. The comparisons illustrate the accuracy of the model in predicting the narrow-band and one-third octave-band vibration response for excitation frequencies up to 2 kHz.

Comparison of Finite Element Models for Predicting Structural Vibration

1993 ◽  
Author(s):  
Shung H. Sung ◽  
Michael P. Fannin ◽  
Donald J. Nefske ◽  
Francis H. K. Chen
Keyword(s):  
Finite Element ◽  
Hybrid Model ◽  
Simple Structure ◽  
Element Model ◽  
Vibration Response ◽  
Structural Vibration ◽  
Finite Element Models ◽  
Lumped Mass ◽  
Measured Velocity ◽  
Vibration Data

Abstract Three structural finite-element models of a small aluminum box with moderately thick walls, representative of a powertrain casting structure, are assessed by comparisons with measured vibration data. The finite element models are: (1) a plate element model, (2) a solid element model, and (3) a hybrid model consisting of plate, beam, and rigid elements. Both lumped- and consistent-mass formulations are evaluated. Comparisons are made with the measured velocity vibration response to shaker excitation. The consistent-mass plate model and the lumped-mass solid model are found to be comparable in accuracy, while the hybrid model can be tuned to achieve the greatest accuracy by matching the measured mode frequencies. The study illustrates the difficulty in accurately predicting the narrow-band vibration response of even a relatively simple structure. However, it is shown that all three models predict a similar one-third octave-band response, which is a vibration measure commonly used in practice.

Parameters Performance to the Vibration Isolation in Three-Dimensional Elastic Floating Raft Isolation System

2012 ◽  
Vol 472-475 ◽  
pp. 2659-2662 ◽  
Author(s):  
Guo He Jiang ◽  
Gang Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Vibration Isolation ◽  
Three Dimensional ◽  
Vibration Response ◽  
System Model ◽  
The Finite Element Method ◽  
Isolation System ◽  
Floating Raft ◽  
Element Method

Based on the three-dimensional elastic floating raft isolation system model, this paper using the finite element method to calculate vibration response of the system, and then analyze the performance of floating raft under different mass and stiffness, providing useful conclusions for vibration isolation designing.

A Structural-Acoustic Vehicle System Model for Noise and Vibration Analysis

2003 ◽  
Author(s):  
Shung H. Sung ◽  
Donald J. Nefske ◽  
Douglas A. Feldmaier ◽  
Spencer J. Doggett
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Exhaust System ◽  
Element Model ◽  
Interior Noise ◽  
System Model ◽  
Structural Vibration ◽  
Vehicle Interior ◽  
Front Suspension ◽  
Vehicle System

A structural-acoustic finite-element model of a sedan-type automotive vehicle is developed and experimentally evaluated for predicting vehicle interior noise and structural vibration. The vehicle system model is developed from finite-element models of the major structural subsystems, which include the trimmed body, front suspension, rear suspension, powertrain and exhaust system. An acoustic finite-element model of the passenger compartment cavity is coupled with the vehicle system model to predict the interior noise response. The predicted interior noise and structural vibration by the vehicle system model are compared with the measured responses for shaker excitation at the axle to 200 Hz. The comparisons demonstrate the accuracy of the structural-acoustic vehicle system model, and they indicate where modeling improvements are required.

Performance of a Stirling Engine Regenerator Having Finite Mass

1986 ◽  
Vol 108 (4) ◽  
pp. 669-673 ◽  
Author(s):  
J. D. Jones
Keyword(s):  
Finite Element ◽  
Pressure Variation ◽  
Stirling Engine ◽  
System Model ◽  
Finite Mass ◽  
Element System ◽  
The Matrix ◽  
Cyclic Variations ◽  
Good Agreement ◽  
Engine Power

The performance of a Stirling engine regenerator subjected to sinusoidal mass flow rate and pressure variation is analyzed. It is shown that cyclic variations in the temperature of the matrix due to its finite mass lead to an increase in the apparent regenerator effectiveness, but a decrease in engine power. Approximate closed-form expressions for both of these effects are deduced. The results of this analysis are compared with the predictions of a finite-element system model, and good agreement is found.

FEM/BEM Simulation of Vibroacoustics of a Fluid-Loaded, Stiffened Plate Under Combined Force-Moment Excitation

2000 ◽  
Author(s):  
H. Zheng ◽  
C. Cai ◽  
G. R. Liu ◽  
K. Y. Lam
Keyword(s):  
Numerical Simulation ◽  
Acoustic Radiation ◽  
Normal Modes ◽  
Vibration Response ◽  
Structural Vibration ◽  
Stiffened Plate ◽  
Coupled Modes ◽  
Force Moment ◽  
Surrounding Fluid ◽  
Element Method

Abstract A numerical simulation of structural vibration and acoustic radiation is presented for a finite, fluid-loaded plate reinforced with two sets of orthotropic stiffeners. The attempt is to achieve a physical understanding of the dynamic behaviour and especially the acoustic radiation of the stiffened plate under combined force and moment excitations. Finite element method (FEM) is employed for calculation of the in-vacuo normal modes of the stiffened plate. The coupled modes with a heavy fluid (water), vibration response and acoustic radiation of the plate under given force and/or moment excitation are calculated using boundary element method (BEM). Numerical simulation results are detailed to address the significance of moment in combined force-moment excitations and, more importantly, the cancelling of the combined excitation in both structural vibration response and the associated acoustic radiation into the surrounding fluid.

Vibration Suppression of Mistuned Coupled-Blade-Disk Systems Using Piezoelectric Circuitry Network

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Hongbiao Yu ◽  
K. W. Wang
Keyword(s):  
Piezoelectric Transducer ◽  
Vibration Suppression ◽  
Structural Vibration ◽  
Bladed Disks ◽  
Disk Model ◽  
Bladed Disk ◽  
Engine Order ◽  
Optimal Network ◽  
Random Mistuning ◽  
Engine Components

For bladed-disk assemblies in turbomachinery, the elements are often exposed to aerodynamic loadings, the so-called engine order excitations. It has been reported that such excitations could cause significant structural vibration. The vibration level could become even more excessive when the bladed disk is mistuned, and may cause fatigue damage to the engine components. To effectively suppress vibration in bladed disks, a piezoelectric transducer networking concept has been explored previously by the authors. While promising, the idea was developed based on a simplified bladed-disk model without considering the disk dynamics. To advance the state of the art, this research further extends the investigation with focus on new circuitry designs for a more sophisticated and realistic system model with the consideration of coupled-blade-disk dynamics. A novel multicircuit piezoelectric transducer network is synthesized and analyzed for multiple-harmonic vibration suppression of bladed disks. An optimal network is derived analytically. The performance of the network for bladed disks with random mistuning is examined through Monte Carlo simulation. The effects of variations (mistuning and detuning) in circuit parameters are also studied. A method to improve the system performance and robustness utilizing negative capacitance is discussed. Finally, experiments are carried out to demonstrate the vibration suppression capability of the proposed piezoelectric circuitry network.

Sign in / Sign up

Export Citation Format

Share Document