A Three-Dimensional Finite Element Damage Mechanics Model to Simulate Fretting Wear of Hertzian Line and Circular Contacts in Partial Slip Regime

2021 ◽  
pp. 1-26
Author(s):  
Arman Ahmadi ◽  
Farshid Sadeghi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modulus Of Elasticity ◽  
Damage Mechanics ◽  
Element Model ◽  
Operating Conditions ◽  
Fretting Wear ◽  
Partial Slip ◽  
Slip Regime ◽  
Line Contacts

Abstract In this investigation, a 3D finite element model (FEM) was developed to study fretting wear of Hertzian circular and line contacts. The wear law incorporated in this model is based on the accumulated dissipated energy (ADE). A stress-based damage mechanics finite element model using the ADE was developed to determine wear of non-conformal bodies in contact. Voronoi tessellation was used to simulate the microstructure of the materials during the fretting process. To simulate the wear area, a material removal approach was implemented in the model. The FEM was used to investigate partial slip regimes under various operating conditions. The normal and shear surface tractions for the circular and line contacts were applied to the domain in order to improve the computational efficiency. The influence of modulus of elasticity, hardness and coefficient of friction on the partial slip fretting phenomenon were studied. In order to verify the model, several fretting wear tests were conducted using AISI 8620 steel and AISI 1566 steel in partial slip regime of circular contact configuration. The properties for each material such as the modulus of elasticity, hardness, and the grain size were measured experimentally and compared with the model. For the defined load and displacement amplitude of the experimental fretting tests, both materials have shown a partial slip behavior in the initial cycles and then transition to a gross slip regime. The numerical model predicted the worn surface and wear rate in partial slip regime which corroborated well with these experimental test results.

scholarly journals Failure Analysis of Composite Pinned Joints Based on Continuum Damage Mechanics

2018 ◽  
Vol 36 (5) ◽  
pp. 848-855
Author(s):  
Hongliang Tuo ◽  
Xiaoping Ma ◽  
Zhixian Lu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Element Model ◽  
Fracture Plane ◽  
Continuum Damage ◽  
Bearing Strength ◽  
Matrix Damage ◽  
Pinned Joints

The paper conducted bearing tests on composite pinned joints with four different stacking sequences. The bearing strength and bearing chord stiffness were obtained. The influence of stacking sequences on failure modes, bearing strength and bearing chord stiffness was discussed. Based on continuum damage mechanics, a three-dimensional finite element model of composite pinned joint under bearing load was built, where the maximum strain criterion was employed for initiation and bi-liner damage constitutive relation for revolution of fiber damage, while the physical-based Puck criterion was used for matrix damage initiation, and matrix damage revolution depended on the effective strain on the fracture plane. The failure mode, bearing strength and bearing chord stiffness of composite pinned joint were discussed with this model under which the non-linear shear behavior and in-situ strength effects were considered. Good agreements between test results and numerical simulations validates the accuracy and applicability of the finite element model.

Finite Element Analysis of Structural Strength of Concrete Mixing Truck’s Frame

2014 ◽  
Vol 945-949 ◽  
pp. 1143-1149
Author(s):  
Hai Xia Sun ◽  
Hua Kai Wei ◽  
Xiao Fang Zhao ◽  
Jia Rui Qi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Structural Strength ◽  
Element Model ◽  
Basic Element ◽  
Operating Conditions ◽  
Frame Structure ◽  
Element Analysis ◽  
The Finite Element Model

The finite element model of the concrete mixing truck’s frame is builded by using shell as basic element, and the process of building the finite element model of the balance suspension is introduced in detail. Based on this, frame’s stress on five types of typical operating conditions are calculated by using the finite element analysis software, NASTRAN, and results can show the dangerous position and the maximum stress position on the frame. The analysis result on structural strength can provide the basis for further improving the frame structure.

Comparing Measured Responses of an Offshore Structure with Operational Modal Analysis assisted Classical Model Approach

2020 ◽  
pp. 1-10
Author(s):  
Bruna Nabuco ◽  
Sandro D. Amador ◽  
Evangelos I. Katsanos ◽  
Ulf T. Tygesen ◽  
Erik Damgaard Christensen ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Element Model ◽  
Operating Conditions ◽  
Operational Modal Analysis ◽  
Mode Shapes ◽  
Wave Forces ◽  
Wave Load ◽  
Offshore Structure

Abstract Aiming to ensure the structural integrity of an offshore structure, wave-induced responses have been measured during normal operating conditions. Operational Modal Analysis is applied to the data obtained from continuously monitoring the structure. Sensors placed only on the topside of an offshore platform are sufficient to provide information to identify the modal properties of the structure, such as natural frequencies, damping ratios, and mode shapes. A finite element model is created and updated in line with the identified dynamic properties for applying a modal expansion technique in the interest of accessing information at any point of the structure. Wave radars are also placed at the platform from which the wave forces are calculated based on basic industrial standard models. In this way, the wave kinematics are estimated according to the linear wave theory associated with Wheeler stretching. Since this study is related to offshore structures composed by slender elements, the wave forces are estimated using Morison formulation. By assigning typical values to the drag and inertia coefficients, wave loads are estimated and applied to the updated finite element model. For the diffraction effect, the wave load has also been evaluated according to MacCamy and Fuchs theory. The responses obtained from this procedure are compared with measured responses. In addition to describing the process, this paper presents a case study to verify the theory using monitoring data from a tripod jacket. Results indicate realistic response estimation that contributes to the knowledge about the state of the structure.

Tube-to-Tubesheet Joints: Maximum Tensile Stress and Contact Pressure Due to Thermal Loading and Temperature Cycling

2002 ◽  
Author(s):  
Mahdi A. Allam ◽  
Andre Bazergui ◽  
Luc Marchand ◽  
Michel Derenne
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Finite Element Model ◽  
Contact Pressure ◽  
Thermal Loading ◽  
Element Model ◽  
Maximum Tensile Stress ◽  
Temperature Cycling ◽  
Operating Conditions ◽  
Service Reliability

Service reliability and durability of tubular heat exchangers and steam generators are much dependent on the proper response of the tube-to-tubesheet joints to the operating conditions. In this paper a 2-D axisymmetric finite element model is proposed and compared to a 3-D finite element solution for the purpose of predicting the temperature effect on the residual contact pressure and maximum tensile residual stresses of such joints. A parametric study using the finite element results shows that, although thermal loading and temperature cycling have a negligible effect on the maximum tensile residual stresses, the room-temperature initial residual contact pressure may be completely relieved following the initiation of plastic deformation in either the tube or the tubesheet during thermal loading. A comparison between the results of the proposed finite element model and those obtained from the literature shows good agreement. A simplified analytical approach, which may be used for the design of tube-to-tubesheet joints, is also proposed to predict the joint behavior at the operating conditions.

Mechanics Analysis and Optimization of the Reachstacker Spreader

2014 ◽  
Vol 1078 ◽  
pp. 266-270
Author(s):  
Yu Feng Shu ◽  
Yong Feng Zheng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Maximum Stress ◽  
Element Model ◽  
Static Strength ◽  
Operating Conditions ◽  
Mechanics Analysis ◽  
Calculation Results ◽  
Improvement Measures ◽  
The Finite Element Model

This paper establishes the finite element model of reachstacker spreader, makes static strength calculation under eight typical operating conditions with rated load, based on the calculation results, it points out the weaknesses of spreader and gives some corresponding improvement measures for the drawbacks. Further analysis shows that the maximum stress of improved spreader mechanism has reduced 10.1%, which demonstrates the effectiveness of improvements.

scholarly journals FINITE ELEMENT MODEL OF DYNAMIC TRAIN-BRIDGE INTERACTION

2020 ◽  
Vol 22 (6) ◽  
pp. 154-166
Author(s):  
S. V. Efimov ◽  
K. O. Zhunev
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Properties ◽  
Accumulation Rate ◽  
Dynamic Stiffness ◽  
Oscillation Amplitude ◽  
Element Model ◽  
Operating Conditions ◽  
Railway Bridges ◽  
Bridge Span

Innovative heavy wagons with a 25–27 tf axle load and the freight train movement organization having a higher weight and length are being put into operation in Russia. New operating conditions of railway bridges require an assessment of bearing capacity, durability, accumulation rate of fatigue damage and reliability. The important parameters are the dynamic properties of railway bridges (frequencies and modes of natural vibrations, decay rate, dynamic stiffness).The aim of this work is to determine the dynamic interaction of trains having different structure, weight and length with a railway bridge using numerical modeling in the midas Civil bridge software. The proposed model is verified by the dynamic parameters of spans (natural vibration frequencies), which are determined during the bridge inspection using a Tensor-MS system.The modal analysis is given to the finite element model. The lowest natural modes of the bridge are determined. Based on numerical simulation of the interaction between the train and the bridge unfavorable speed of trains is calculated leading to an increase in the oscillation amplitude of the bridge span as well as in the bridge dynamic coefficient with regard to the design features of the train structure and composition.

Vibration Control of Beams Using Electro-Magnetic Damping Treatment

1999 ◽  
Author(s):  
J. Oh ◽  
S. Poh ◽  
M. Ruzzene ◽  
A. Baz
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Operating Conditions ◽  
Viscoelastic Damping ◽  
Magnetic Damping ◽  
Magnetic Forces ◽  
Magnetic Layers ◽  
Electro Magnetic ◽  
Passive Constrained Layer Damping

Abstract A new class of structural damping treatments is introduced. This class is the Electro-Magnetic Damping Treatment (EMDT) which relies in its operation on a viscoelastic damping layer sandwiched between two magnetic layers. Interaction between the magnets generates magnetic forces that enhance the compressional damping mechanism of the viscoelastic layer. With proper tuning of the magnetic forces, in response to the structural vibration, undesirable resonances and catastrophic failures can be avoided. The fundamentals and the underlying phenomena associated with the EMDT are investigated theoretically and experimentally. A finite element model is developed to describe the interaction between the dynamics of flexible beams, the viscoelastic damping layer and the magnetic layers. The validity of the developed finite element model is checked experimentally using aluminum beams treated with EMDT patches. The beam/EMDT system is subjected to sinusoidal excitations and its multi-mode response is monitored when the magnetic layers are activated or not. Several control strategies are considered to activate the magnetic layers including simple PD controllers. The performance of the uncontrolled and controlled system is determined at various operating conditions. Comparisons with conventional Passive Constrained Layer Damping (PCLD) treatments emphasize the potential of the EMDT treatment as an effective means for controlling structural vibrations.

Analysis of Dynamic Characteristic of Numerical Remanufacture Machine's Feeding System

2010 ◽  
Vol 156-157 ◽  
pp. 1360-1365
Author(s):  
Qiu Lin Pu ◽  
Xiao Diao Huang ◽  
Wen Zheng Ding
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Operating Conditions ◽  
Ball Screw ◽  
Response Analysis ◽  
Feeding System ◽  
Nature Frequency ◽  
Grinding Machine ◽  
The Finite Element Model

In this paper,the ball screw feeding system’s dynamic characteristics of a numerical remanufacture grinding machine is analyzed using the FEM. Discusses the modeling method of ball screw system into the finite element model and established the combination of finite element model. Through the modal analysis and the harmonious response analysis, the nature frequency and vibration mode of the feeding system and typical operating conditions of excitation in the harmonic responsehave have been gotten,thus the dependable basis for the construction’s optimization and dynamic function’s increasing of the feeding system is provided, ensure the numerical remanufacture will be success.

scholarly journals Prediction of Load-Bearing Capacity of Composite Parts with Low-Velocity Impact Damage: Identification of Intra- and Inter-Ply Constitutive Models

2020 ◽  
Vol 1 (1) ◽  
pp. 59-78
Author(s):  
Aleksandr Cherniaev ◽  
Svetlana Pavlova ◽  
Aleksandr Pavlov ◽  
Valeriy Komarov
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Bearing Capacity ◽  
Damage Mechanics ◽  
Impact Damage ◽  
Element Model ◽  
Physical Parameters ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Simulation Methodology

Assessments of residual load-carrying capacity are often conducted for composite structural components that have received impact damage. The availability of a verified simulation methodology can provide significant cost savings when such assessments are required. To support the development of a reliable and accurate simulation methodology, this study investigated the predictive capabilities of a stacked solid-shell finite element model of a cylindrical composite component with a damage mechanics-based description of the intra-ply material response and a cohesive contact model used for simulation of the inter-ply behavior. Identification of material properties for the model was conducted through mechanical characterization. Special attention was paid to understanding the influence of non-physical parameters of the intra- and inter-ply material models on predicting compressive failure load of damaged composite cylinders. Calibration of the model conducted using the response surface methodology allowed for identifying rational values of the non-physical parameters. The results of simulations with the identified and calibrated finite element model showed reasonable correlation with experimental data in terms of the predicted failure loads and post-impact and post-failure damage modes. The investigated modeling technique can be recommended for evaluating the residual load-bearing capacity of flat and curved composite parts with impact damage working under the action of compressive loads.

Fretting Wear Modeling of Cylindrical Line Contact in Plane-Strain Borne by the Finite Element Method

2019 ◽  
Vol 86 (6) ◽  
Author(s):  
Huaidong Yang ◽  
Itzhak Green
Keyword(s):  
Finite Element ◽  
Plane Strain ◽  
Beam Theory ◽  
Fretting Wear ◽  
Partial Slip ◽  
Wear Volume ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Line Contacts ◽  
Theoretical Predictions

This is the first study to develop an empirical formulation to predict fretting wear (volume removal) under frictional conditions for plane-strain line contacts as borne out by the finite element analysis (FEA). The contact is between a deformable half-cylinder rubbing against a deformable flat block. The FEA is guided by detailed physical conceptions, with results that subsequently lead to the methodical modeling of fretting wear. The materials in contact are first set to steel/steel, then to Alloy617/Alloy617, and finally to copper/copper. Various coefficients of friction (COFs) and the Archard Wear Model are applied to the interface. Initially, pure elastic conditions are investigated. The theoretical predictions for the wear volume at the end of the partial slip condition in unidirectional sliding contact agree very well with the FEA results. The empirical formulation for the initial gross slip distance is constructed, again revealing results that are in good agreement with those obtained from the FEA for different materials and for various scales. The Timoshenko beam theory and the tangential loading analysis of a half elastic space are used to approximate the deflection of the half-cylinder and the flat block, respectively. That theory supports well the empirical formulation, matching closely the corresponding FEA results. The empirical formulation of the wear volume for a general cycle under fretting motion is then established. The results are shown to be valid for different materials and various COFs when compared with the FEA results. Finally, plasticity is introduced to the model, shown to cause two phenomena, namely junction growth and larger tangential deformations. Wear is shown to either increase or decrease depending on the combined influences of these two phenomena.

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