Numerical Simulation of Grinding-Hardened Layer's Depth in the Reciprocating Grinding of 45 Steel

2013 ◽  
Vol 401-403 ◽  
pp. 656-659
Author(s):  
Ju Dong Liu ◽  
Wei Yuan ◽  
Zhi Long Xu ◽  
Dong Ming Yu
Keyword(s):  
Numerical Simulation ◽  
Numerical Calculation ◽  
Heat Source ◽  
Experimental Results ◽  
Moving Heat Source ◽  
Source Theory ◽  
Temperature Filed ◽  
Simulation Results ◽  
Grinding Hardening

Based on the experiment of reciprocating grinding and in accordance with Jaeger moving heat source theory and the triangle model of the heat source, this paper established temperature filed of grinding-hardening machine and conducted numerical calculation with the temperature filed of grinding by the software ANSYS. Then it predicated the grinding-hardened layers depth in accordance with the results of numerical calculation, and compared with the experimental results to verify the rationality of the simulation results.

Generalized Thermoelastic Responses of a Piezoelectric Rod Subjected to a Moving Heat Source

2007 ◽  
Vol 353-358 ◽  
pp. 1149-1152
Author(s):  
Tian Hu He ◽  
Li Cao
Keyword(s):  
Numerical Calculation ◽  
Heat Source ◽  
Laplace Transformation ◽  
Moving Heat Source ◽  
Governing Equations ◽  
Laplace Inversion ◽  
Thermally Induced ◽  
Numerical Laplace Inversion ◽  
Generalized Thermoelastic ◽  
Elastic Responses

Based on the Lord and Shulman generalized thermo-elastic theory, the dynamic thermal and elastic responses of a piezoelectric rod fixed at both ends and subjected to a moving heat source are investigated. The generalized piezoelectric-thermoelastic coupled governing equations are formulated. By means of Laplace transformation and numerical Laplace inversion the governing equations are solved. Numerical calculation for stress, displacement and temperature within the rod is carried out and displayed graphically. The effect of moving heat source speed on temperature, stress and temperature is studied. It is found from the distributions that the temperature, thermally induced displacement and stress of the rod are found to decrease at large source speed.

scholarly journals Numerical Simulations of V-Shaped Plates Subjected to Blast Loadings: A Validation Study

2016 ◽  
Vol 10 (11) ◽  
pp. 203
Author(s):  
Mohd Zaid Othman ◽  
Qasim H. Shah ◽  
Muhammad Akram Muhammad Khan ◽  
Tan Kean Sheng ◽  
M. A. Yahaya ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Variable Mass ◽  
Blast Loading ◽  
Experimental Results ◽  
Average Difference ◽  
Simulation Results ◽  
Blast Loadings ◽  
Carrier Vehicle ◽  
Good Agreement

A series of numerical simulations utilizing LS-DYNA was performed to determine the mid-point deformations of V-shaped plates due to blast loading. The numerical simulation results were then compared with experimental results from published literature. The V-shaped plate is made of DOMEX 700 and is used underneath an armour personal carrier vehicle as an anti-tank mine to mitigate the effects of explosion from landmines in a battlefield. The performed numerical simulations of blast loading of V-shaped plates consisted of various angles i.e. 60°, 90°, 120°, 150° and 180°; variable mass of explosives located at the central mid-point of the V-shaped vertex with various stand-off distances. It could be seen that the numerical simulations produced good agreement with the experimental results where the average difference was about 26.6%.

scholarly journals MEMS-Based Integrated Triaxial Electrochemical Seismometer

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1156
Author(s):  
Wenjie Qi ◽  
Bowen Liu ◽  
Tian Liang ◽  
Jian Chen ◽  
Deyong Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Ground Motion ◽  
Small Volume ◽  
Three Dimensional ◽  
Experimental Results ◽  
Good Prospect ◽  
High Symmetry ◽  
Noise Levels ◽  
Sensitivity Curves ◽  
Simulation Results

This paper presents a micro-electromechanical systems (MEMS)-based integrated triaxial electrochemical seismometer, which can detect three-dimensional vibration. By integrating three axes, the integrated triaxial electrochemical seismometer is characterized by small volume and high symmetry. The numerical simulation results inferred that the integrated triaxial electrochemical seismometer had excellent independence among three axes. Based on the experimental results, the integrated triaxial electrochemical seismometer had the advantage of small axial crosstalk and could detect vibration in arbitrary directions. Furthermore, compared with the uniaxial electrochemical seismometer, the integrated triaxial electrochemical seismometer had similar sensitivity curves ranging from 0.01 to 100 Hz. In terms of random ground motion response, high consistencies between the developed integrated triaxial electrochemical seismometer and the uniaxial electrochemical seismometer could be easily observed, which indicated that the developed integrated triaxial electrochemical seismometer produced comparable noise levels to those of the uniaxial electrochemical seismometer. These results validated the performance of the integrated triaxial electrochemical seismometer, which has a good prospect in the field of deep geophysical exploration and submarine seismic monitoring.

Influence of Forming Residual Stresses on the Welding Distortions of Two Thick Plates

2009 ◽  
Vol 83-86 ◽  
pp. 125-132 ◽  
Author(s):  
Sebastien Gallée ◽  
Antoine Martin ◽  
Vincent Robin ◽  
Daniel Nelias
Keyword(s):  
Numerical Simulation ◽  
Electron Beam ◽  
Heat Source ◽  
Residual Stresses ◽  
Electron Beam Welding ◽  
Initial Conditions ◽  
Rolling Process ◽  
Vacuum Vessel ◽  
Thick Plates ◽  
Simulation Results

The manufacturing of the ITER (International Thermonuclear Experimental Reactor) vacuum vessel involves the welding of thick deformed plates. The aim of this study is to investigate the influence of forming residual stresses on the welding distortions of two thick plates. The plates are deformed using a three point rolling process. A first numerical simulation is performed to investigate the residual stresses induced by this process. The forming residual stresses are taken into account as initial conditions to perform the electron beam welding simulation of a deformed plate. This simulation first requires calibrating the heat source. Two welding simulations are then performed: the first one with residual stresses and the second one without. The comparison of the simulation results points out a low effect of the residual stresses on the electron beam welding distortions. As a result, in the next electron beam welding simulations of the vacuum vessel, no forming residual stresses will be taken into account.

An Analysis of the Evaluation Methods for Thermal Transmittance of Curtain Wall System Based on Simulators

2017 ◽  
Vol 865 ◽  
pp. 383-389 ◽  
Author(s):  
Min Jung Bae ◽  
Yu Min Kim ◽  
Gyeong Seok Choi ◽  
Jae Sik Kang ◽  
Hyun Jung Choi
Keyword(s):  
Numerical Simulation ◽  
Evaluation System ◽  
Evaluation Methods ◽  
Experimental Results ◽  
Curtain Wall ◽  
Performance Evaluation System ◽  
Thermal Transmittance ◽  
Simulation Results ◽  
Primary Evaluation ◽  
Wall System

With the window rating system being enforced, window companies are required to assign window ratings to their products. As the window ratings is based on the experimental results of fenestration, they are required to spend a lot of time and money conducting laboratory tests in order to assign window ratings to all their products. Through the window performance evaluation system using simulation, the thermal transmittance of products calculated based on numerical simulation can be used in place of experimental results to obtain the window rating. To ensure the credibility of simulation results, it is necessary to use the correct evaluation methods and primary information derived from in use practice should be available for the numerical simulation. The purpose of this paper is to investigate the evaluation methods that the simulator actually uses for the thermal performance of fenestration in WINDOW/THERM. The evaluation methods used by twenty-one simulators were investigated using primary evaluation methods for numerical simulation as the criteria. This study found that most of the simulation results were not trustworthy even though they were similar to experimental results because the evaluation methods used by simulators are incorrect. Furthermore, to enhance the credibility of simulation results, the simulator should be provided with the detailed information used in practice related to the evaluation performance of numerical simulation.

Efficiency Metallic Leading Edge Structure Bird Strike Resistant Design

2011 ◽  
Vol 338 ◽  
pp. 84-89 ◽  
Author(s):  
Mei Ying Zhao ◽  
Jing Jing Li
Keyword(s):  
Numerical Simulation ◽  
Absorption Rate ◽  
Leading Edge ◽  
Experimental Results ◽  
Structural Quality ◽  
Bird Strike ◽  
Edge Structure ◽  
Simulation Based ◽  
Simulation Results ◽  
Resistant Structure

This article investigated a new metallic leading edge bird strike resistant structure, using corrugate board as its enhanced component to absorb more bird kinetic energy. This structure was called as Corrugate Board Leading Edge (CBLE) structure. To verify the structure’s bird strike resistant ability, numerical simulation based on the LS-DYNA was carried out, and succeeding experiments were performed. However, the experimental results were not exciting. They were not as the simulation results we expected. The reasons were analyzed through this article. Finally a rivet-relative model was created considering the influence of riveting. This model was proved to be accurate by comparing with experimental results. Based on the analysis above, an Optimized CBLE (O-CBLE) structure was used to optimize the bird strike resistant ability, the energy absorption rate of O-CBLE structure increased 11.4% while the structural quality was only slightly increased.

Numerical Investigation of a Novel Grooved Vapor Chamber

2008 ◽  
Author(s):  
Ming Zhang ◽  
Zhongliang Liu ◽  
Guoyuan Ma
Keyword(s):  
Numerical Simulation ◽  
Heat Source ◽  
Liquid Film ◽  
Thin Liquid Film ◽  
Source Region ◽  
Transfer Model ◽  
Vapor Chamber ◽  
Starting Point ◽  
Condensation Surface ◽  
Simulation Results

An effective thermal spreader can achieve more uniform heat flux distribution and thus enhance heat dissipation of heat sinks. Vapor chamber is one of highly effective thermal spreaders. In this paper, a novel grooved vapor chamber was designed. The grooved structure of the vapor chamber can improve its axial and radial heat transfer and also can form the capillary loop between condensation and evaporation surfaces. A two dimensional heat and mass transfer model for the grooved vapor chamber is developed. The numerical simulation results show the thickness distribution of liquid film in the grooves is not uniform. The temperature and velocity field in vapor chamber are obtained. The thickness of the liquid film in groove is mainly influenced by pressure of vapor and liquid beside liquid-vapor interface. The thin liquid film in heat source region can enhance the performance of vapor chamber, but if the starting point of liquid film is backward beyond the heat source region, the vapor chamber will dry out easily. The optimal filling ratio should maintain steady thin liquid film in heat source region of vapor chamber. The vapor condenses on whole condensation surface, so the condensation surface achieves great uniform temperature distribution. By comparing the experimental results with numerical simulation results, the reliability of the numerical model can be verified.

Vertical Riser VIV Simulation in Uniform Current

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Kevin Huang ◽  
Hamn-Ching Chen ◽  
Chia-Rong Chen
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Method ◽  
Cross Flow ◽  
Experimental Results ◽  
Critical Parameters ◽  
Outer Diameter ◽  
Higher Harmonics ◽  
Uniform Current ◽  
Simulation Results

Recently, some riser vortex-induced vibrations (VIVs) experimental data have been made publicly available (oe.mit.edu/VIV/) including a 10 m riser VIV experiment performed by Marintek, Trondheim, Norway, and donated by ExxonMobil URC, Houston, TX, USA. This paper presents our numerical simulation results for this 10 m riser and the comparisons with the experimental results in uniform current. The riser was made of a 10 m brass pipe with an outer diameter of 0.02 m (L/D=482) and a mass ratio of 1.75. The riser was positioned vertically with top tension of 817 N and pinned at its two ends to the test rig. Rotating the rig in the wave tank would simulate the uniform current. In the present numerical simulation the riser’s ends were pinned to the ground and a uniform far field incoming current was imposed. The riser and its surrounding fluid were discretized using 1.5×106 elements. The flow field is solved using an unsteady Reynolds-averaged Navier–Stokes (RANS) numerical method in conjunction with a chimera domain decomposition approach with overset grids. The riser is also discretized into 250 segments. Its motion is predicted through a tensioned beam motion equation with external force obtained by integrating viscous and pressure loads on the riser surface. Then the critical parameters including riser VIV amplitude (a) to the riser outer diameter (D) ratio (a/D), vorticity contours, and motion trajectories were processed. The same parameters for the experimental data were also processed since these data sets are in “raw time-histories” format. Finally, comparisons are made and conclusions are drawn. The present numerical method predicts similar dominant modes and amplitudes as the experiment. It is also shown that the cross flow VIV in the riser top section is not symmetric to that of the bottom section. One end has considerably higher cross flow vibrations than the other end, which is due to the nondominant modal vibrations in both in-line and cross flow directions. The computational fluid dynamics (CFD) simulation results also agree with the experimental results very well on the riser vibrating pattern and higher harmonics response. The higher harmonics were studied and it is found that they are related to the lift coefficients, hence the vortex shedding patterns. It is concluded that the present CFD approach is able to provide reasonable results and is suitable for 3D riser VIV analysis in deepwater and complex current conditions.

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