Modeling of Flange Joints for the Nonlinear Dynamic Analysis of Gas Turbine Engine Casings

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
C. W. Schwingshackl ◽  
E. P. Petrov
Keyword(s):  
Nonlinear Analysis ◽  
Gas Turbine ◽  
Normal Load ◽  
Nonlinear Dynamic Analysis ◽  
Aircraft Engine ◽  
Partial Slip ◽  
Analysis Tool ◽  
Flange Joint ◽  
Contact Interface ◽  
Element Analysis

The finite element analysis of individual components of aircraft engine casings provides high accuracy and a good agreement with the measured response data. However, when these components are assembled, the accuracy of such predictions can significantly deteriorate since models describing stiffness and friction properties of joints are linearized. A full nonlinear analysis of the casing flanges is required to fully include the influence of the bolted joints, model the flexibility in the contact interface, and consider the nonlinear behavior of the contact due to partial slip and separation. In this paper different nonlinear models of casings are investigated with an available nonlinear analysis tool: A parametric study of the contact interface meshes is conducted to identify a satisfying analysis approach. The dynamic flange behavior is analyzed in detail, including effects of the bolt and normal load distribution. A comparison of the introduced nonlinear modeling with more traditional rigid or linear-elastic flange joint models is carried out to evaluate the effect of the nonlinear approach. The study demonstrates the nonlinear nature of a casing flange joint and highlights the need to include them in the analysis. The detailed modeling of the contact interaction of joints gives an insight in the nonlinear contact behavior of flanges of aircraft engine casings, and the predictive capabilities for the nonlinear analysis of gas turbine engines.

Modelling of Flange Joints for the Nonlinear Dynamic Analysis of Gas Turbine Engine Casings

2012 ◽  
Author(s):  
C. W. Schwingshackl ◽  
E. P. Petrov
Keyword(s):  
Nonlinear Analysis ◽  
Gas Turbine ◽  
Nonlinear Dynamic Analysis ◽  
Aircraft Engine ◽  
Partial Slip ◽  
Analysis Tool ◽  
Nonlinear Behaviour ◽  
Flange Joint ◽  
Contact Interface ◽  
Contact Behaviour

The finite element analysis of individual components of aircraft engine casings provides high accuracy and a good agreement with the measured response data. However, when these components are assembled, the accuracy of such predictions can significantly deteriorate since models describing stiffness and friction properties of joints are linearised. A full nonlinear analysis of the casing flanges is required to fully include the influence of the bolted joints, model the flexibility in the contact interface, and consider the nonlinear behaviour of the contact due to partial slip and separation. In this paper different nonlinear models of casings are investigated with an available nonlinear analysis tool; A parametric study of the contact interface meshes is conducted to identify a satisfying analysis approach. The dynamic flange behaviour is analysed in detail, including effects of the bolt and normal load distribution. A comparison of the introduced nonlinear modelling with more traditional rigid or linear-elastic flange joint models is carried out to evaluate the effect of the nonlinear approach. The study demonstrates the nonlinear nature of a casing flange joint and highlights the need to include them in the analysis. The detailed modelling of the contact interaction of joints, gives an insight in the nonlinear contact behaviour of flanges of aircraft engine casings, and the predictive capabilities for the nonlinear analysis of gas turbine engines.

Modeling and Validation of the Nonlinear Dynamic Behavior of Bolted Flange Joints

2013 ◽  
Vol 135 (12) ◽  
Author(s):  
C. W. Schwingshackl ◽  
D. Di Maio ◽  
I. Sever ◽  
J. S. Green
Keyword(s):  
Nonlinear Analysis ◽  
Aircraft Engine ◽  
Nonlinear Damping ◽  
Element Analysis ◽  
Structural Support ◽  
Dynamic Finite Element Analysis ◽  
Damping Behavior ◽  
Bolted Flange ◽  
Engine Components

Linear dynamic finite element analysis can be considered very reliable today for the design of aircraft engine components. Unfortunately, when these individual components are built into assemblies, the level of confidence in the results is reduced since the joints in the real structure introduce nonlinearity that cannot be reproduced with a linear model. Certain types of nonlinear joints in an aircraft engine, such as underplatform dampers and blade roots, have been investigated in great detail in the past, and their design and impact on the dynamic response of the engine is now well understood. With this increased confidence in the nonlinear analysis, the focus of research now moves towards other joint types of the engine that must be included in an analysis to allow an accurate prediction of the engine behavior. One such joint is the bolted flange, which is present in many forms on an aircraft engine. Its main use is the connection of different casing components to provide the structural support and gas tightness to the engine. This flange type is known to have a strong influence on the dynamics of the engine carcase. A detailed understanding of the nonlinear mechanisms at the contact is required to generate reliable models and this has been achieved through a combination of an existing nonlinear analysis capability and an experimental technique to accurately measure the nonlinear damping behavior of the flange. Initial results showed that the model could reproduce the correct characteristics of flange behavior, but the quantitative comparison was poor. From further experimental and analytical investigations it was identified that the quality of the flange model is critically dependent on two aspects: the steady stress/load distribution across the joint and the number and distribution of nonlinear elements. An improved modeling approach was developed that led to a good correlation with the experimental results and a good understanding of the underlying nonlinear mechanisms at the flange interface.

Contact Analysis of Tire Tread Rubber on Flat Surface with Microscopic Roughness3

2006 ◽  
Vol 34 (4) ◽  
pp. 237-255 ◽  
Author(s):  
M. Kuwajima ◽  
M. Koishi ◽  
J. Sugimura
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Sliding Friction ◽  
Tangential Force ◽  
Partial Slip ◽  
Real Contact Area ◽  
Element Analysis ◽  
Real Contact ◽  
Local Slip ◽  
Tread Rubber

Abstract This paper describes experimental and analytical studies of the dependence of tire friction on the surface roughness of pavement. Abrasive papers were adopted as representative of the microscopic surface roughness of pavement surfaces. The rolling∕sliding friction of tire tread rubber against these abrasive papers were measured at low slip velocities. Experimental results indicated that rolling∕sliding frictional characteristics depended on the surface roughness. In order to examine the interfacial phenomena between rubber and the abrasive papers, real contact length, partial slip, and apparent friction coefficient under vertical load and tangential force were analyzed with two-dimensional explicit finite element analysis in which slip-velocity-dependent frictional coefficients were considered. Finite element method results indicated that the sum of real contact area and local partial slip were larger for finer surfaces under the same normal and tangential forces. In addition, the velocity-dependent friction enhanced local slip, where the dependence of local slip on surface roughness was pronounced. It proved that rolling∕sliding friction at low slip ratio was affected by local frictional behavior at microslip regions at asperity contacts.

Finite Element Analysis of Reinforced Concrete Beams with Exterior FRP Shell

2011 ◽  
Vol 243-249 ◽  
pp. 1461-1465
Author(s):  
Chuan Min Zhang ◽  
Chao He Chen ◽  
Ye Fan Chen
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Contact Interface ◽  
Accurate Calculation ◽  
Element Analysis

The paper makes an analysis of the reinforced concrete beams with exterior FRP Shell in Finite Element, and compares it with the test results. The results show that, by means of this model, mechanical properties of reinforced concrete beams with exterior FRP shell can be predicted better. However, the larger the load, the larger deviation between calculated values and test values. Hence, if more accurate calculation is required, issues of contact interface between the reinforced concrete beams and the FRP shell should be taken into consideration.

scholarly journals Use of Dynamic Analysis to Investigate the Behaviour of Short Neutral Sections in the Overhead Line Electrification

2021 ◽  
Vol 6 (5) ◽  
pp. 62
Author(s):  
John Morris ◽  
Mark Robinson ◽  
Roberto Palacin
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Simulation ◽  
Model Simulation ◽  
Analysis Tool ◽  
Overhead Line ◽  
Element Analysis ◽  
Novel Approach ◽  
Section Model ◽  
The Uk ◽  
Neutral Section

The ‘short’ neutral section is a feature of alternating current (AC) railway overhead line electrification that is often unreliable and a source of train delays. However hardly any dynamic analysis of its behaviour has been undertaken. This paper briefly describes the work undertaken investigating the possibility of modelling the behaviour using a novel approach. The potential for thus improving the performance of short neutral sections is evaluated, with particular reference to the UK situation. The analysis fundamentally used dynamic simulation of the pantograph and overhead contact line (OCL) interface, implemented using a proprietary finite element analysis tool. The neutral section model was constructed using physical characteristics and laboratory tests data, and was included in a validated pantograph/OCL simulation model. Simulation output of the neutral section behaviour has been validated satisfactorily against real line test data. Using this method the sensitivity of the neutral section performance in relation to particular parameters of its construction was examined. A limited number of parameter adjustments were studied, seeking potential improvements. One such improvement identified involved the additional inclusion of a lever arm at the trailing end of the neutral section. A novel application of pantograph/OCL dynamic simulation to modelling neutral section behaviour has been shown to be useful in assessing the modification of neutral section parameters.

Finite Element Analysis of a Gasketed Flange Joint Under Combined Internal Pressure and Thermal Transient Loading

2007 ◽  
Author(s):  
Muhammad Abid ◽  
Javed A. Chattha ◽  
Kamran A. Khan
Keyword(s):  
Finite Element Analysis ◽  
Steady State ◽  
Internal Pressure ◽  
Thermal Loading ◽  
Flange Joint ◽  
Element Analysis ◽  
Transient Loading ◽  
Thermal Transient ◽  
Transient Thermal ◽  
Bolted Flange

Performance of a bolted flange joint is characterized mainly by its ‘strength’ and ‘sealing capability’. A number of analytical and experimental studies have been conducted to study these characteristics only under internal pressure loading. In the available published work, thermal behavior of the pipe flange joints is discussed under steady state loading with and without internal pressure and under transient loading condition without internal pressure. The present design codes also do not address the effects of steady state and thermal transient loading on the structural integrity and sealing ability. It is realized that due to the ignorance of any applied transient thermal loading, the optimized performance of the bolted flange joint can not be achieved. In this paper, in order to investigate gasketed joint’s performance i.e. joint strength and sealing capability under combined internal pressure and transient thermal loading, an extensive nonlinear finite element analysis is carried out and its behavior is discussed.

The Onset of Plastic Yielding in a Spherical Shell Compressed by a Rigid Flat

2010 ◽  
Vol 78 (1) ◽  
Author(s):  
Longqiu Li ◽  
Izhak Etsion ◽  
Andrey Ovcharenko ◽  
Frank E. Talke
Keyword(s):  
Spherical Shell ◽  
Normal Load ◽  
Empirical Relation ◽  
Solid Sphere ◽  
Plastic Yielding ◽  
Element Analysis ◽  
Shell Parameter ◽  
Shell Geometry ◽  
Limiting Value ◽  
Critical Contact

The onset of plastic yielding in a spherical shell loaded by a rigid flat is analyzed using finite element analysis. The effect of spherical shell geometry and material properties on the critical normal load, critical interference, and critical contact area, at the onset of plastic yielding, is investigated and the location where plastic yielding first occurs is determined. A universal dimensionless shell parameter, which controls the behavior of the spherical shell, is identified. An empirical relation is found for the load-interference behavior of the spherical shell prior to its plastic yielding. A limiting value of the dimensionless shell parameter is identified above which the shell behaves like a solid sphere.

Characterization of gas turbine ingested sand particles based on electrostatic signal

2021 ◽  
pp. 095765092110464
Author(s):  
Jianzhong Sun ◽  
Heng Jiang ◽  
Caiqiong Yang ◽  
Ruochen Liu
Keyword(s):  
Theoretical Analysis ◽  
Gas Turbine ◽  
Simulation Study ◽  
Aircraft Engine ◽  
In Situ Monitoring ◽  
Service Reliability ◽  
Fem Modeling ◽  
Initial Development ◽  
Sand Particles ◽  
Particle Ingestion

Particle ingestion into a gas turbine can have serious effects on both performance and engine in-service reliability. Thus there exists a need for in situ monitoring and characterizing particulate matter entering an aircraft engine inlet for the purposes of engine damages estimation and prognosis. This paper presents the initial development of Ingested Debris Monitoring System (IDMS) signal processing method of characterizing the ingested particles. A theoretical analysis and simulation study were carried out to study the relationships between the characteristics of the ingested sand particles and the features of the IDMS signal both in frequency- and time-domain. A Finite-Element Modeling (FEM) for the IDMS Sensor was developed, then the validated FEM modeling was used for simulation experiments of particles ingestion under various conditions of different particle moving speeds, concentrations and charge-to-mass ratios. Results of the theoretical analysis and simulation study demonstrates the feasibility and effectiveness of the proposed method to provide real time information characterizing the size and concentration of ingested sand particles, and will serve as an impetus to carry out further research.

Nonlinear Analysis of R.C Beams Strengthened with CFRP

2012 ◽  
Vol 166-169 ◽  
pp. 1517-1520
Author(s):  
Wen Sheng Li ◽  
Kai Wang
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Nonlinear Analysis ◽  
Element Model ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Element Analysis ◽  
Flexural Performance ◽  
Reinforced Polymer ◽  
Flexural Resistance

In order to study on the flexural performances of beams strengthened with external bonded carbon fiber reinforced polymer（CFRP）sheets, nonlinear analysis is carried out by using software ANSYS. The results show that a reasonable finite element model, using a reasonable solution strategy can be a good simulation of CFRP flexural performance of reinforced concrete beams, and finite element analysis results with the experimental results have good consistency .The beams reinforced by carbon fiber polymer，the capacity of flexural resistance increased with the numbers of carbon fiber paste sheets, reinforced components of flexural capacity significantly improved, but the extent of its increase is not proportional with the numbers of carbon fiber paste sheets.

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