Dynamic modeling of a gear transmission system containing damping particles using coupled multi-body dynamics and discrete element method

Considering flexibility of the support shafts as well as bearing supports, the effect of meshing impact force and meshing stiffness on the dynamic behavior of a gear transmission system in electric vehicle is investigated in this paper using the proposed hybrid user-defined element method. First, a structured grid generation method is introduced to establish accurate mesh models of the pinion and gear teeth. Second, coupling the tooth mesh models and the flexible shafts as well as bearings, two finite element models are, respectively, constructed for the two helical gear pairs of the electric vehicle reduction unit to calculate the meshing impact force. Next, the basic mechanism of meshing impact is explained in detail according to the finite element results, and the impact force is determined as one of the main internal excitations substituted into the dynamic model established by the hybrid user-defined element method. Under 50 N m input torque and 12,010 r/min rotational speed of the input shaft, the simulation results by the hybrid user-defined element method indicate that the example system reaches a steady state and the vibrations primarily occur at the meshing frequencies. With an increment of 600 r/min of the input rotational speed, it is also concluded from the results that (1) the calculated impact force approximately presents linear growth with the increase of the input shaft rotational speed and (2) the root mean square values of the vibration acceleration generally grow with the increase of the speed.

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Analytical investigation on geared rotor system with multi-body fault based on finite element method

Journal of Vibration and Control ◽

10.1177/1077546318783366 ◽

2018 ◽

Vol 25 (2) ◽

pp. 408-422 ◽

Cited By ~ 1

Author(s):

Wei Li ◽

Daqian Pang

Keyword(s):

Fault Diagnosis ◽

High Speed ◽

Structural Characteristics ◽

Rapid Development ◽

Transmission System ◽

Gear Transmission ◽

Heavy Load ◽

Fault Type ◽

Gear Transmission System ◽

Multi Body

With the rapid development of modern industry, the situation of high speed and heavy load is becoming even more relevant in the gear transmission system. Under the condition of high speed and heavy load, the fault type and frequency of the gear transmission system are gradually increasing. Effective and accurate detection of fault location and fault type is one of the difficult problems in today’s fault diagnosis. In the case of high speed and heavy load, the probability of multi-body fault is greatly increased. However, most of the current fault diagnosis methods are limited to the study of single fault characteristics, and do not take into account the multi body fault. In this paper, the single crack, gear coupling crack, single shaft crack, and gear and shaft coupling crack signal are analyzed by means of the short-time Fourier transform, and the corresponding fault characteristics of different fault types are found out. The modal analysis of the fault state of the gear transmission system is carried out, the structural characteristics of the gear drive are verified, and the influence of the different fault forms on the vibration characteristics of the gear is compared.

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Modeling of the fragmentation by Discrete Element Method

DYMAT 2009 - 9th International Conferences on the Mechanical and Physical Behaviour of Materials under Dynamic Loading ◽

10.1051/dymat/2009215 ◽

2009 ◽

Author(s):

C. Mariotti ◽

V. Michaut ◽

J. F. Molinari

Keyword(s):

Discrete Element Method ◽

Discrete Element ◽

Element Method

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Discrete element method to model cracking for two layer systems

TAPPI Journal ◽

10.32964/tj18.2.101 ◽

2019 ◽

Vol 18 (2) ◽

pp. 101-108

Author(s):

Daniel Varney ◽

Douglas Bousfield

Keyword(s):

Discrete Element Method ◽

Flexural Modulus ◽

Single Layer ◽

Discrete Element ◽

Flexural Stress ◽

Layer System ◽

Three Point Bending ◽

Moving Force ◽

Coating Layers ◽

Element Method

Cracking at the fold is a serious issue for many grades of coated paper and coated board. Some recent work has suggested methods to minimize this problem by using two or more coating layers of different properties. A discrete element method (DEM) has been used to model deformation events for single layer coating systems such as in-plain and out-of-plain tension, three-point bending, and a novel moving force picking simulation, but nothing has been reported related to multiple coating layers. In this paper, a DEM model has been expanded to predict the three-point bending response of a two-layer system. The main factors evaluated include the use of different binder systems in each layer and the ratio of the bottom and top layer weights. As in the past, the properties of the binder and the binder concentration are input parameters. The model can predict crack formation that is a function of these two sets of factors. In addition, the model can predict the flexural modulus, the maximum flexural stress, and the strain-at-failure. The predictions are qualitatively compared with experimental results reported in the literature.

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