scholarly journals Surface Roughness 3D Modelling and its Association With Leak Tightness for a Metal-to-Metal Contacting Surface

2017 ◽  
Author(s):  
Ali A. Anwar ◽  
William Dempster ◽  
Yevgen Gorash ◽  
David Nash
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Element Model ◽  
Dynamics Model ◽  
Relief Valve ◽  
Pressure Relief ◽  
Fea Model ◽  
Gas Leak ◽  
Leak Tightness ◽  
Fluid Interaction

This paper presents an overview of a numerical method developed to allow one-way structure-fluid interaction of a scanned representative surface of a Pressure Relief Valve (PRV) measuring 100 μm by 100 μm to be incorporated into a coupled finite element and computational fluid dynamics model to investigate gas leak rates through micro-gaps in full size metal-to-metal contacting components. The virtual representative surface is created via a real scan using a 3D micro coordinate and surface roughness measurement system. The scan of the physical surface is converted to a CAD format and a finite element model generated which is deformed for a given loading condition. The micro-gaps of the deformed FEA model are extracted and imported into the CFD solver to find the resulting volumetric/mass flow rate for the same set of pressure conditions. This coupled approach allows the leakage rate to be found based on only the surface roughness of metal-to-metal sealing surfaces. This methodology can now be expanded to understand the behaviour and response of metal-to-metal deformable contacting surface components under pressure. Thereafter, the design objective is to minimise or eliminate component leakage.

Residual Stress Distribution in Hard-Facing of Pressure Relief Valve Seat

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Li Ai ◽  
Xinhai Yu ◽  
Wenchun Jiang ◽  
Wanchuck Woo ◽  
Xiaofeng Ze ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Infrared Imaging ◽  
Element Model ◽  
Pressure Relief Valve ◽  
Stress Distributions ◽  
Relief Valve ◽  
Pressure Relief

In this study, for the hard-facing of spring-loaded pressure relief valve seats, the residual stress distributions after the tungsten inert gas welding, (TIG) postwelded heat treatment and subsequent surface turning were investigated. The heat input parameters of welding were calibrated using an infrared imaging and thermocouples. The residual stress distributions were computed using three-dimensional finite element model. The neutron diffraction approach was employed to verify the finite element calculation. It is found that, the surface temperature during hard-facing welding shows a double ellipsoidal shape with the highest value of around 1570 °C. The high residual stress zones are located exactly under the welded joint except a slight deviation in the hoop direction. The magnitudes of tensile residual stresses in the three directions increase with their corresponding locations from the root of the joint into the base metal. The residual stresses in all of the three directions decrease significantly after the heat treatment. After surface turning, the residual stresses are tensile except for those close to the inner surface that are compressive in axial and radial directions.

scholarly journals Investigation on aerodynamic characteristics of bionic membrane nano rotor

2021 ◽  
Vol 18 ◽  
pp. 175682932110433
Author(s):  
Shanyong Zhao ◽  
Zhen Liu ◽  
Ke Lu ◽  
Dacheng Su ◽  
Shangjing Wu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Structural Parameters ◽  
Element Model ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Dynamics Model ◽  
Interaction Method ◽  
Calculation Results ◽  
The Finite Element Model

In this paper, the bionic membrane structure is introduced to improve the aerodynamic performance of nano rotor at the low Reynolds number. The aerodynamic characteristics of nano rotor made of hyperelastic material as membrane blades are studied. Firstly, based on the hyperelastic constitutive model, a finite element model of the rotor is established and compared with the results of the modal test to verify the accuracy of the model. Then the computational fluid dynamics model of membrane nano rotor is established which combined with the finite element model. The aerodynamic characteristics of the membrane rotor under hovering conditions are studied using fluid–structure interaction method. It is found that the calculation results matched well with the experiment results. The design of the structural parameters such as the membrane proportion, shape, and position of the membrane rotor is optimized. The influence of each parameter on the aerodynamic performance of the rotor is obtained. Under certain structural conditions, the performance can be effectively improved, which provides a new idea for the design of the nano rotor.

A Finite Element Analysis Study of Non-Linear Behavior in a Bolted Connection

1999 ◽  
Author(s):  
Richard B. Englund ◽  
David H. Johnson ◽  
Shannon K. Sweeney
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Sliding Friction ◽  
Element Model ◽  
Element Analysis ◽  
Bolted Connection ◽  
Fea Model ◽  
Linear Behavior ◽  
Radial Loading ◽  
The Finite Element Model

Abstract A finite element analysis (FEA) model of the interaction of a nut and bolt was used to investigate the effects of sliding, friction, and yielding in a bolted connection. The finite element model was developed as a two-dimensional, axisymmetric system, which allowed the study of axial and radial loading and displacements. This model did not permit evaluation of hoop or torsional effects such as tightening or the helical thread form. Results presented in this paper include the distribution of load between consecutive threads, the relative sliding along thread faces, and the stress distribution and regions of yielding in the model. Finally, a comparison to previous, linear analysis work and to published experimental data is made to conclude the paper.

scholarly journals Study of mechanical aspects of leak tightness in a pressure relief valve using advanced FE-analysis

2016 ◽  
Vol 43 ◽  
pp. 61-74 ◽  
Author(s):  
Yevgen Gorash ◽  
William Dempster ◽  
William D. Nicholls ◽  
Robert Hamilton ◽  
Ali A. Anwar
Keyword(s):  
Fe Analysis ◽  
Pressure Relief Valve ◽  
Relief Valve ◽  
Pressure Relief ◽  
Leak Tightness

scholarly journals Strength of the shaft/hub joint using a finite element model

2019 ◽  
pp. 9-18
Author(s):  
Manuel Salgado-Cruz ◽  
Claudia Cortés-García ◽  
Dariusz Slawomir Szwedowicz-Wasik ◽  
Eladio Martínez-Rayón
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Contact Stiffness ◽  
Load Capacity ◽  
Element Model ◽  
Numerical Results ◽  
Normal Contact ◽  
Interference Fit ◽  
Axial Load Capacity ◽  
Normal Contact Stiffness

This article describes the effect of the roughness size on the axial slip strength between the parts of shaft/hub joints with interference fit. The surface roughness was obtained from a turning process with different finishes (fine, medium and rough). A finite element modeling was developed, which uses a normal contact stiffness equivalent to the size of the surface roughness between the joint pieces to represent the real contact. In order to validate the numerical model, theoretical results of contactpressure and extraction force of the shaft/hub joint with smooth elements were compared with the corresponding numerical results obtained. The numerical results from studies that considered the size of the surface roughness showed that the axial load capacity of the joint decreased with larger roughness.

Study of Alternative Assembly Patterns Using Finite Element Analysis and Lab Tests

2018 ◽  
Author(s):  
Gong H. Jung ◽  
Wesley Pudwill ◽  
Elysia J. Sheu
Keyword(s):  
Finite Element ◽  
Elastic Interaction ◽  
Element Model ◽  
Potential Method ◽  
Test Results ◽  
Element Analysis ◽  
Fea Model ◽  
Assembly Method ◽  
Bolt Stress ◽  
Lab Test

A total of 24 lab tests were performed to evaluate two different joint assembly patterns (legacy and an alternative pattern), two lubricant types (Nickel based and Moly-Disulphide based), and two types of torque wrenches (Hydraulic and Pneumatic). Bolt stress was measured during assembly using load indicating bolts (SPC4). Assembly time was also measured since alternative assembly patterns have been recognized as a potential method for improving assembly efficiency without negatively impacting bolt pre-load scatter. In order to understand the bolt stress distribution in both of the legacy and alternative assembly patterns, a finite element model was developed to simulate wrench sequences specified by ASME PCC-1. The FEA model included the effect of elastic interaction of the bolts and flange. The FEA results indicate similar behavior when compared to the lab test results, and the FEA study was extended to two other alternative assembly patterns. This paper summarizes the results of the FEA and lab tests on a 24” NPS Class 300 flange and may provide validation and supporting information for users who are considering the use of a more efficient assembly method such as the alternative assembly patterns presented in ASME PCC-1.

scholarly journals Failure analysis of a frangible composite cover: A transient-dynamics study

2016 ◽  
Vol 51 (18) ◽  
pp. 2607-2617
Author(s):  
Deng’an Cai ◽  
Guangming Zhou ◽  
Yuan Qian ◽  
Vadim V Silberschmidt
Keyword(s):  
Finite Element ◽  
Failure Analysis ◽  
Failure Criterion ◽  
Element Model ◽  
Transient Dynamics ◽  
Dynamics Model ◽  
Test Device ◽  
Weak Zone ◽  
Failure Pressure ◽  
Model Failure

A transient-dynamics model based on the approximate Riemann algorithm is proposed for the failure analysis of a frangible composite canister cover. The frangible cover, manufactured with a traditional manual lay-up method, is designed to conduct a simulated missile launch test using a specially developed test device. Deformation of the cover’s centre is determined using a transient-dynamics finite element model; failure pressure for the frangible cover is obtained based on a failure criterion and compared with simulated experimental results. Weak-zone position of the frangible cover has a significant effect on failure pressure compared to that of deformation of the cover’s centre. With the same structure of the weak-zone, an increase in its height can first raise and then reduce the level of failure pressure of the frangible cover. Close agreements between the experimental and numerical results are observed.

scholarly journals Nondestructive Evaluation Of A Polymer Composite Hip Implant Using Lock-In Thermography

2021 ◽  
Author(s):  
Ehsan Rahim
Keyword(s):  
Finite Element ◽  
Experimental Testing ◽  
Element Model ◽  
Element Analysis ◽  
Hip Implant ◽  
Polyamide 12 ◽  
Strain Pattern ◽  
Fea Model ◽  
Lock In ◽  
Good Agreement

Lock-in thermography, combined with finite element analysis and experimental testing, was used to investigate the stress/strain pattern in a novel composite hip implant made of carbon fibre and polyamide 12 (CF/PA12). In this study, the geometry of the hip implant was first modelled and analysed in ANSYS workbench 11. Different virtual loads of 800N, 1400N and 2200N were applied on the finite element model of the hip stem at an adduction angle of 15º, thereby replicating the present experimental setup. The values of strains obtained were confirmed by replicating the experiment by using strain gauges. A Pearson's correlation (R²=0.98) was obtained, which indicated good agreement between the FEA model and experimental hip stem. The hip implant was again subjected to similar loading conditions, and stresses were recorded by using a thermal camera at corresponding vertices. The comparison of results showed good agreement between the values of stress calculated from the strain gauge experiment and stress obtained from thermography. This study showed that it was possible to find stresses in a hip implant reliably by thermography.

Analysis of Elastic Deformation of Axial Foil Hydrodynamic Thrust Bearing Used in Turbine Generator

2011 ◽  
Vol 188 ◽  
pp. 199-202
Author(s):  
Yu Kui Wang ◽  
Z.Q. Zeng ◽  
Zhen Long Wang ◽  
Y.S. Huang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Elastic Deformation ◽  
Thrust Bearing ◽  
Element Model ◽  
Lubricant Layer ◽  
Turbine Generator ◽  
Fea Model ◽  
Set Up ◽  
The Finite Element Model

In this paper, an elastic deformation of the axial foil hydrodynamic thrust bearing used in 100KW gas turbine generator is studied. The finite element model of the foil hydrodynamic thrust bearing was established using Solidworks and ANSYS. The foil hydrodynamic thrust bearing which considered foil deformation was analyzed and calculated based on the results of the approximate calculation. The FEA model considered the interaction of plane foil deformation and wave foil. The wave foil was not hypothesized as the linear distributed spring when set up the finite element model. The ANSYS results have demonstrated that the deformation of foil bearing designed based on the result of numerical calculation can meet the requirement of minimal film thickness of bearing lubricant layer.

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