scholarly journals Understanding the Enhanced Protective Mechanism of CoCrNiAlY－YSZ－LaMgAl11O19 Double-Ceramic Coating With Aluminum Plating

2021 ◽  
Author(s):  
Junfei Xu ◽  
Zhiguo Wang ◽  
Shuai Hu ◽  
Yongjun Feng ◽  
Suying Hu ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Ceramic Coating ◽  
Simulation Method ◽  
Protective Mechanism ◽  
Good Adhesion ◽  
Air Exposure ◽  
Protection Effect ◽  
Protection Mechanism ◽  
Element Simulation ◽  
Plating Layer

To understand the enhanced protection mechanism of CoCrNiAlY-YSZ-LaMgAl11O19 dou-ble-layer ceramic coating with aluminum plating, a finite element simulation method was used to simulate the distribution of thermal stress in the coating in all directions. The results show that in the air exposure of the un-aluminized coating, high temperature causes a large radial thermal stress on the surface of the LaMgAl11O19 (LMA) layer, and it increases with the increase in temperature, which is the main reason for the initiation of axial cracks. After arc aluminum plating, the aluminum plating layer effectively inhibited the volume shrinkage of the coating through good adhesion to the coating and internal diffusion, the thermal stress of the coating was considerably reduced, and the CoCrNiAlY-YSZ-LMA coating had an effective enhancement and protection effect; however, there was still a certain amount of shear thermal stress inside the LMA layer, the top of the crack, and the bottom of the crack. This thermal stress caused the initi-ation of radial microcracks in the LMA layer, which also becomes a risk point for the failure of the aluminum coating.

A Research of Shaft Modal Simulation Method Based on the Preloaded Angular Contact Ball Bearing

2013 ◽  
Vol 389 ◽  
pp. 364-370
Author(s):  
Bei Li ◽  
Jian Bin Zhang ◽  
Lu Sha Jiang
Keyword(s):  
Simulation Analysis ◽  
Simulation Method ◽  
Numerical Control ◽  
Angular Contact Ball Bearing ◽  
Tightening Force ◽  
Shaft System ◽  
Element Simulation ◽  
Rolling Element ◽  
Bearing Stiffness ◽  
Main Spindle

In order to analysis modal characteristic of bearing with pre-tightening force on main spindle of numerical control lathe, this paper proposes a model of spindle modality analysis. This model is used to simulate the preloaded bearing shaft system modal, and the simulation results are verified by modal experiment. This paper takes 7005c as the research object to establish the equivalent-spring model based on the Hertz theory considering the pre-tightening force, whose focus is dealing with the contact between bearings rolling element and raceway. Then the model will be used to get the bearing stiffness for finite element simulation analysis. The shafting modal with preloaded bearing test platform is structured to get the shaft system modal parameters, which is compared with and verified the simulation analysis.

Study on Dent Resistance with Whole Process Optimization Method for Body's Cover Based on the Variable Conditions

2013 ◽  
Vol 700 ◽  
pp. 164-169
Author(s):  
Kai Song ◽  
Chao Wang ◽  
Tao Chen ◽  
Ze Zhou
Keyword(s):  
Process Optimization ◽  
Optimization Problems ◽  
Simulation Method ◽  
Optimization Method ◽  
Fast Simulation ◽  
Whole Process ◽  
Element Simulation ◽  
Contact Nonlinearity ◽  
Abaqus Software ◽  
Process Method

This paper aims at cover body dent resistance optimization problems, developed a whole process method using the finite element simulation method and the corresponding engineering experience to solve the dent resistance problem. Use of Tcl/Tk language to develop the script for fast simulation model consider material nonlinearity and contact nonlinearity, Use Abaqus software to calculate the results, and then customized to optimize use of simplified script parameters on changes in the working conditions of the structure will be optimized. The results show that this set of process optimization method to solve the variable conditions dent resistance is quickly, efficiently and accurately.

scholarly journals Analysis of Vertical Stiffness of Air Spring Based on Finite Element Method

2018 ◽  
Vol 153 ◽  
pp. 06006
Author(s):  
Jiatong Ye ◽  
Hua Huang ◽  
Chenchen He ◽  
Guangyuan Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Element Model ◽  
Simulation Method ◽  
Bench Test ◽  
Air Spring ◽  
Vertical Stiffness ◽  
Element Simulation ◽  
Element Method

In this paper, a finite element model of membrane air spring in the vehicle is established, and its vertical stiffness characteristics under a certain inflation pressure are analysed. The result of finite element simulation method is compared with the result of the air spring bench test. The accuracy and reliability of the finite element simulation method in nonlinear analysis of air spring system are verified. In addition, according to the finite element method, the influence of the installation of the air spring limit sleeve on its stiffness is verified.

scholarly journals Numerical Simulation Study on the Front Shape and Thermal Stresses in Growing Multicrystalline Silicon Ingot: Process and Structural Design

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1053
Author(s):  
Chengmin Chen ◽  
Guangxia Liu ◽  
Lei Zhang ◽  
Guodong Wang ◽  
Yanjin Hou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Thermal Stress ◽  
Thermal Stresses ◽  
Simulation Method ◽  
Power Ratio ◽  
Radial Temperature ◽  
Front Shape ◽  
Simulation Results ◽  
Insulation Block ◽  
Transient Numerical Simulation

In this paper, a transient numerical simulation method is used to investigate the effects of the two furnace configurations on the thermal field: the shape of the melt–crystal (M/C) interface and the thermal stress in the growing multicrystalline ingot. First, four different power ratios (top power to side power) are investigated, and then three positions (i.e., the vertical, angled, and horizontal positions) of the insulation block are compared with the conventional setup. The power ratio simulation results show that with a descending power ratio, the M/C interface becomes flatter and the thermal stress in the solidified ingot is lower. In our cases, a power ratio of 1:3–1:4 is more feasible for high-quality ingot. The block’s position simulation results indicate that the horizontal block can more effectively reduce the radial temperature gradient, resulting in a flatter M/C interface and lower thermal stress.

The Study on Airborne Equipments Life Prediction Based on the Finite Element Simulation under Comprehensive Stress

2013 ◽  
Vol 365-366 ◽  
pp. 224-228
Author(s):  
Tian Ma ◽  
Chuan Ri Li ◽  
Shuang Long Rong
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Life Prediction ◽  
Single Point ◽  
Simulation Method ◽  
Distribution Fitting ◽  
Kinetic Experiment ◽  
Element Simulation ◽  
Vibration Stress ◽  
Equipment Lifetime

To predict an airborne equipment lifetime with finite element simulation method, use ANSYS and Flothem, respectively, to analysis vibration stress and temperature stress, corrected by kinetic experiment; then import the results into the failure prediction software-CALCE PWA, set the intensity and duration of stress according to its mission profile, finally get the component failure life prediction results under comprehensive temperature and vibration stress; extract the Monte-Carlo simulation data, use the single point of failure distribution fitting, fault clustering and multipoint distribution fusion method to get the board and the whole machines lifetime and reliability prediction. The design refinement suggestion of the airborne equipment is given at the end of the conclusion.

A Study of Delamination Mechanism of Thermal Barrier Coating under Thermal Cycling and Aging Condition by Residual Stress History

2009 ◽  
Vol 417-418 ◽  
pp. 173-176
Author(s):  
Hiroyuki Waki ◽  
Akira Kobayashi
Keyword(s):  
Residual Stress ◽  
Thermal Stress ◽  
Thermal Cycling ◽  
Thermal Aging ◽  
Ceramic Coating ◽  
Plane Surface ◽  
Diffraction Method ◽  
Thermal Barrier ◽  
Stress History ◽  
Bond Coating

Thermal barrier coatings (TBCs) have been employed for the insulation of substrates from high temperature in gas turbine plants. The TBC system consists of ceramic top coating, metallic bond coating and substrate. Delamination of the ceramic coating is important problem in TBC systems. In this paper, the delamination mechanism was studied by residual stress history under thermal aging and thermal cycle conditions. In-plane residual stress histories of ceramic coating and bond coating after thermal aging and cycling were measured by X-ray diffraction method. The residual stress under thermal cycling was also calculated by FEM analysis. The results obtained were as follows: (1) in-plane surface residual stresses of the coatings scarcely changed regardless of the increase of thermally grown oxidation (TGO). (2) high compressive thermal stress, residual stress at room temperature, in ceramic coating induced by thermal stress did not occur. It was found that stress of ceramic top coating was relaxed by micro cracks and driving stress of delamination was in-plane high compressive stress.

Numerical optimization for the geometrical configuration of ceramics perform in ZTAP/HCCI wear resistant composites based on actual particle model

2021 ◽  
Author(s):  
Ruiju Xu ◽  
Tianlong Lu ◽  
Jiankang Zhang ◽  
Yehua Jiang ◽  
Xiaoyu Chong ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Solidification Process ◽  
Ceramic Particle ◽  
Particle Model ◽  
Matrix Composites ◽  
Geometrical Configuration ◽  
Ceramic Particles ◽  
High Chromium Cast Iron ◽  
Element Simulation ◽  
Chromium Cast Iron

Abstract In order to reduce the thermal stress in high chromium cast iron (HCCI) matrix composites reinforced by zirconia toughened alumina (ZTA) ceramic particles, finite element simulation is performed to optimize the geometrical configuration of ceramics perform. The previous model simplifies the overall structure of the ceramic particle preform and adds boundary conditions to simulate the particles, which will cause uncontrollable error in the results. In this work, the equivalent grain models are used to describe the actual preform, making the simulation results closer to the actual experimental results. The solidification process of composite material is simulated and the infiltration between molten iron and ceramic particles was realized. Thermal stress in solidification process and compression stress distribution are obtained. The results show that adding 10mm round holes on the preform can improve the performance of the composite, which is helpful to prevent the cracks and increases the plasticity of the material.

Research into Contact Interaction of an Elastic Tool during Rotational Pattern Cutting of Sheet Parts

2016 ◽  
Vol 685 ◽  
pp. 408-412 ◽  
Author(s):  
E.G. Gromova ◽  
A.G. Bakanova
Keyword(s):  
Finite Element ◽  
Mathematical Simulation ◽  
Elastic Medium ◽  
Design Process ◽  
Experimental Research ◽  
Simulation Method ◽  
Medium Pressure ◽  
Element Simulation ◽  
Deformation Processes ◽  
Simulation Results

The paper describes a method of pattern cutting of sheet articles using the elastic medium pressure. Research works have been conducted into feasibility of the suggested pattern cutting using finite element simulation method. The experimental research was conducted into deformation processes during rotational separating stamping of sheet articles by means of elastic medium pressure so that to confirm relevance of the mathematical simulation results. The optimum design process parameter value combinations have been determined for implementing the rotary pattern cutting process.

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