Numerical methods for the dynamic analysis of masonry structures

2006 ◽  
Vol 22 (1) ◽  
pp. 107-130 ◽  
Author(s):  
Silvia Degl'Innocenti ◽  
Cristina Padovani ◽  
Giuseppe Pasquinelli
Keyword(s):  
Numerical Methods ◽  
Dynamic Analysis ◽  
Masonry Structures

Dynamic analysis of a helical gear reduction by experimental and numerical methods

2020 ◽  
Vol 68 (1) ◽  
pp. 48-58
Author(s):  
Chao Liu ◽  
Zongde Fang ◽  
Fang Guo ◽  
Long Xiang ◽  
Yabin Guan ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Fourth Order ◽  
Numerical Models ◽  
Helical Gear ◽  
Operating Conditions ◽  
Dynamic Responses ◽  
Lumped Mass ◽  
Gear Mesh

Presented in this study is investigation of dynamic behavior of a helical gear reduction by experimental and numerical methods. A closed-loop test rig is designed to measure vibrations of the example system, and the basic principle as well as relevant signal processing method is introduced. A hybrid user-defined element model is established to predict relative vibration acceleration at the gear mesh in a direction normal to contact surfaces. The other two numerical models are also constructed by lumped mass method and contact FEM to compare with the previous model in terms of dynamic responses of the system. First, the experiment data demonstrate that the loaded transmission error calculated by LTCA method is generally acceptable and that the assumption ignoring the tooth backlash is valid under the conditions of large loads. Second, under the common operating conditions, the system vibrations obtained by the experimental and numerical methods primarily occur at the first fourth-order meshing frequencies and that the maximum vibration amplitude, for each method, appears on the fourth-order meshing frequency. Moreover, root-mean-square (RMS) value of the acceleration increases with the increasing loads. Finally, according to the comparison of the simulation results, the variation tendencies of the RMS value along with input rotational speed agree well and that the frequencies where the resonances occur keep coincident generally. With summaries of merit and demerit, application of each numerical method is suggested for dynamic analysis of cylindrical gear system, which aids designers for desirable dynamic behavior of the system and better solutions to engineering problems.

SYMBOLIC TREATMENT FOR THE EQUATIONS OF MOTION FOR RIGID MULTIBODY SYSTEMS

2010 ◽  
Vol 34 (1) ◽  
pp. 37-55 ◽  
Author(s):  
Bukoko C. Ikoki ◽  
Marc J. Richard ◽  
Mohamed Bouazara ◽  
Sélim Datoussaïd
Keyword(s):  
Numerical Methods ◽  
Differential Equations ◽  
Dynamic Analysis ◽  
Multibody Systems ◽  
Equations Of Motion ◽  
The World ◽  
Rigid Multibody Systems ◽  
Symbolic Approach ◽  
Rigid Multibody

The library of symbolic C++ routines is broadly used throughout the world. In this article, we consider its application in the symbolic treatment of rigid multibody systems through a new software KINDA (KINematic & Dynamic Analysis). Besides the attraction which represents the symbolic approach and the effectiveness of this algorithm, the capacities of algebraical manipulations of symbolic routines are exploited to produce concise and legible differential equations of motion for reduced size mechanisms. These equations also constitute a powerful tool for the validation of symbolic generation algorithms other than by comparing results provided by numerical methods. The appeal in the software KINDA resides in the capability to generate the differential equations of motion from the choice of the multibody formalism adopted by the analyst.

Gear rattle modelling and analysis for automotive manual transmissions

2001 ◽  
Vol 215 (2) ◽  
pp. 241-258 ◽  
Author(s):  
M Y Wang ◽  
R Manoj ◽  
W Zhao
Keyword(s):  
Numerical Methods ◽  
Differential Equations ◽  
Dynamic Analysis ◽  
Ordinary Differential Equations ◽  
Torsional Vibration ◽  
Software Package ◽  
Power Train ◽  
Analysis Scheme ◽  
Engine Clutch ◽  
Gear Rattle

This paper describes a model for torsional vibration of automotive manual transmissions and its subsequent analysis. The model is developed for the purpose of analysis and prediction of gear rattles. Efforts have been made to include as many components of power train as possible and to study the rattle responses of all the speeds. Elements of the model include engine, clutch, flywheel, laden and unladen gears, and shafts. Numerical methods available in MATLAB for solving the ordinary differential equations are employed for the dynamic analysis. Results are presented to show the effectiveness of the modelling and analysis scheme. A software package has also been developed to build and analyse any power train model. The package was used to analyse the Daimler-Chrysler T350 transmission and the results are presented in the paper. It is shown that the gear rattle may exhibit three major modes of double-sided, single-sided or irregular impacts. A rattle index has been used to compare the rattle levels produced by different gear pairs. This could be very useful for the purpose of tuning the clutch for the best rattle noise reduction.

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