scholarly journals A modal synthesis method for the elastoacoustic vibration problem

2002 ◽  
Vol 36 (1) ◽  
pp. 121-142 ◽  
Author(s):  
Alfredo Bermúdez ◽  
Luis Hervella-Nieto ◽  
Rodolfo Rodríguez
Keyword(s):  
Synthesis Method ◽  
Vibration Problem ◽  
Modal Synthesis

Modal synthesis method of lateral vibration analysis for rotor-bearing system

2002 ◽  
Vol 80 (32) ◽  
pp. 2537-2549 ◽  
Author(s):  
Chun-Ping Zou ◽  
Hong-Xing Hua ◽  
Duan-Shi Chen
Keyword(s):  
Vibration Analysis ◽  
Synthesis Method ◽  
Lateral Vibration ◽  
Modal Synthesis ◽  
Rotor Bearing ◽  
Bearing System

Contact Modeling Technique of a Flexible Piston and Cylinder Using Modal Synthesis Method

2005 ◽  
Author(s):  
W. K. Kim ◽  
S. H. Sohn ◽  
H. J. Cho ◽  
D. S. Bae ◽  
J. H. Choi
Keyword(s):  
Contact Force ◽  
Synthesis Method ◽  
Normal Modes ◽  
Modeling Technique ◽  
Mode Shapes ◽  
Dynamics Analysis ◽  
Contact Modeling ◽  
Static Correction ◽  
Modal Synthesis ◽  
Contact Surfaces

In this paper, contact modeling technique and dynamics analysis of piston and cylinder system are presented by using modal synthesis method. It is very important to select mode shapes representing a global or local behavior of a flexible body due to a specified loading condition. This paper proposes a technique to generate the static correction modes which are nicely representing a motion by a contact force between a piston and cylinder. First normal modes of piston and cylinder under a boundary condition are computed, and then static correction modes due to a contact force applied at contacted nodes are added to the normal modes. Also, this paper proposes an efficient dynamics analysis process while changing the shape of the piston and cylinder. In optimization process or design study, their geometric data can be changed a bit. The slight changes of their contact surfaces make a high variation of the magnitude of a contact force, and it can yield the different dynamic behavior of an engine system. But, since the variations of the normal and correction modes are very small, the re-computation of their normal and correction modes due to the change of contact surfaces can be useless. Until now, whenever their contact surfaces are changed at a design cycle, the modes have been recomputed. Thus, most engineers in industries have been spent many times in very tedious and inefficient design process. In this paper, the normal and correction modes from the basic geometry of the piston and cylinder are computed. If the geometry shape is changed, nodal positions of the original modal model are newly calculated from an interpolation method and changed geometry data. And then the updated nodes are used to compute a precise contact force. The proposed methods illustrated in this investigation have good agreement with results of a nodal synthesis technique and proved that it is very efficient design method.

Alternating Stress Dynamics Analysis of Harmonic Gear Flexible Wheel

2012 ◽  
Vol 546-547 ◽  
pp. 102-109
Author(s):  
Xue Feng Han ◽  
Yang Bai ◽  
Ming Li ◽  
Hong Guang Jia
Keyword(s):  
Synthesis Method ◽  
Drive System ◽  
Dynamics Simulation ◽  
Theoretical Simulation ◽  
Gear Drive ◽  
Modal Synthesis ◽  
Change Trend ◽  
Simulation Results ◽  
To Come ◽  
Stress Simulation

This article is the study of alternating stress of flexible wheel in harmonic gear drive system. Firstly, according to elasticity theory to theoretically analyze flexible wheel stress; then, based on the basic principle of sub-structure modal synthesis method , use the software of UG、PATRAN and ADAMS to carry out co-simulation; Finally, based on the dynamics simulation, to analyze the alternating stress simulation results of flexible wheel and compare theoretical results and simulation results to come conclusion. The results show that: altering stress simulation results of flexible wheel are coincident with theoretical simulation results, have a deeper understand the stress change trend in the drive process of flexible wheel, lay a foundation for further carrying out dynamics simulation of harmonic gear drive system.

Time Domain NV Simulation with A/T Assy Model by Modal Synthesis Method

2018 ◽  
Author(s):  
Yasuhiro Asai ◽  
Tokihito Nagae ◽  
Yasuhide Hirabayashi
Keyword(s):  
Time Domain ◽  
Synthesis Method ◽  
Modal Synthesis

Design for a New Type of Powder Molding Equipment Based on Multibody Dynamics Simulation

2012 ◽  
Vol 468-471 ◽  
pp. 857-862
Author(s):  
Zhen Xing Zheng
Keyword(s):  
Powder Metallurgy ◽  
Multibody Dynamics ◽  
Lagrange Equation ◽  
Low Cost ◽  
Synthesis Method ◽  
Flexible Multibody Dynamics ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Flexible Body ◽  
Modal Synthesis

A new compaction powder metallurgy equipment integrated with the mould and the frame is introduced to substitute the traditional powder metallurgy equipment (P/M). During the design and manufacture, finite element method is used to analyze the motion of the equipment. The Lagrange equation and modal synthesis method for flexible body are constructed, and then the cooperative simulation method using ADAMS and MARC is present for solving flexible multibody dynamics of flexible body. Results show that the design of the structure of the powder metallurgy equipment is feasible and the low cost and the simple structure are its merits compared to the traditional equipment.

Rotor-Blade Coupled Vibration Analysis by Measuring Modal Parameters of Actual Rotor

2009 ◽  
Author(s):  
Akira Okabe ◽  
Takeshi Kudo ◽  
Hideo Yoda ◽  
Shigeo Sakurai ◽  
Osami Matsushita ◽  
...  
Keyword(s):  
Rotor Blade ◽  
Synthesis Method ◽  
Field Testing ◽  
Turbine Rotor ◽  
Modal Parameters ◽  
Coupled Vibration ◽  
Turbine Generator ◽  
Modal Synthesis ◽  
Unique Method ◽  
Spring System

The designers of rotor shafts and blades for a traditional turbine-generator set typically employed their own models and process by neglecting the coupled torsional effect. The torsional coupled umbrella mode of recent longer blades systems designed for higher output and efficiency tends to have nearly doubled the frequency of electric disturbance (i.e., 100 or 120 Hz). In order to precisely estimate the rotor-blade coupled vibration of rotating shafts, the analysis must include a process to identify the parameters of a mathematical model by using a real model. In this paper we propose the use of a unique quasi-modal technique based on a concept similar to that of the modal synthesis method, but which represents a unique method to provide a visually reduced model. An equivalent mass-spring system is produced for uncoupled umbrella mode and modal parameters are measured in an actual turbine rotor system. These parameters are used to estimate the rotor-blade coupled torsional frequencies of a 700-MW turbine-generator set, with the accuracy of estimation being verified through field testing.

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