Contact Stress Analysis and Fatigue Life Prediction of a Turbine Fan Disc

2016 ◽  
Vol 33 (2) ◽  
Author(s):  
Liang Yang ◽  
Shun-Peng Zhu ◽  
Zhiqiang Lv ◽  
Fang-Jun Zuo ◽  
Hong-Zhong Huang

AbstractFan discs are critical components of an aero engine. In this paper, contact stress and life prediction of a turbine fan disc were investigated. A simplified pin/disc model was conducted to simulate the practical working condition under applied loads using finite element (FE) analysis. This study is devoted to examining the effects of interface condition of pin/disc such as gap and coefficient upon the maximum stress. The FE model indicated that the maximum stress occurs at the top right corner in the second pin hole, and larger gap or friction coefficient has a significant effect on the maximum stress. In addition, FE analysis without considering friction is also conducted. The results show that the dangerous point is similar to the result which considers friction and the stress state is relatively larger than that of considering friction. Finally, based on FE analysis result, life prediction for the fan disc is conducted to combine the material

Author(s):  
Zhong Luo ◽  
Lei Li ◽  
Yang Yang ◽  
Xiaojie Hou ◽  
Jiaxi Liu ◽  
...  

The elastic ring is widely used in elastic support structures of aero-engine because of its simple structure and convenient manufacturing. In this paper, two elastic ring models, 3D and 2D models, are proposed, where the fillets between the bulges and ring are considered. The 2D model is more efficient for the calculation of stiffness characteristics. The 3D model can be used to obtain the maximum stress position in the axial direction. Then the experimental testing is carried out to verify the accuracy and effectiveness of the proposed models. Based on the proposed models, the stiffness nonlinearity and critical load of the elastic ring are found for the first time, which can be used to determine the normal working load range. Moreover, the elastic ring models with and without fillets are developed, and the effect of the fillets on stress is discussed. The results show that the stress is reduced by considering the fillets, which are not considered in the existing literature.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
M. S. H. Bhuiyan ◽  
I. A. Choudhury ◽  
M. Dahari ◽  
Y. Nukman ◽  
S. Z. Dawal

A gear-based knee joint is designed to improve the performance of mechanical-type above-knee prostheses. The gear set with the help of some bracing, and bracket arrangement, is used to enable the prosthesis to follow the residual limb movement. The motion analysis and finite-element analysis (FEA) of knee joint components are carried out to assess the feasibility of the design. The maximum stress of 29.74 MPa and maximum strain of 2.393e−004 are obtained in the gear, whereas the maximum displacement of 7.975 mm occurred in the stopper of the knee arrangement. The factor of safety of 3.5 obtained from the FE analysis indicated no possibility of design failure. The results obtained from the FE analysis are then compared with the real data obtained from the literature for a similar subject. The pattern of motion analysis results has shown a great resemblance with the gait cycle of a healthy biological limb.


Author(s):  
Hithesh Channegowda ◽  
Raghu V. Prakash ◽  
Anandavel Kaliyaperumal

Fan blades of an aero-engine assembly are the critical components that are subjected to Foreign Object Damage (FOD) such as bird impact. Bird impact resulting in deformation damage onto set of blades, which in turn alters the blade mass and stiffness distribution compared to undamaged blades. This paper presents the numerical evaluation of dynamic characteristics of bird impact damaged blades. The dynamic characteristics evaluated are the natural frequencies and mode shapes of post impact damaged set of blades and the results are compared with undamaged set of blades. The frequencies and mode shapes are evaluated for the damaged blades, with varying angles of bird impact and three blade rotational speeds. Study reveals that first bending and torsional frequencies of deformed blades are significantly affected compared to undamaged set of blades. Study emphasize the need to evaluate the natural frequencies deformed blades, that has direct bearing on High Cycle Fatigue (HCF) life of the blade, to ensure post damaged blades operate safely for certain time to reduce inflight accidents and safe landing.


Author(s):  
Tae-young Ryu ◽  
J. B. Choi ◽  
Kyoung S. Lee

For decades, the PWSCC on the penetration nozzles like BMI and CEDM nozzles are widely occurred all around the world. The PWSCC is dependent on the tensile stress condition, specific materials and chemical environment. Therefore, to evaluate the severity of the PWSCC, prediction of the welding residual stress on the J-groove welding part in the penetration nozzles is essential. Residual stress can be measured by using experimental methods like deep-hole drilling and X-ray diffraction, etc. However, the results of experimental methods are quite doubtable and these methods are hard to apply on the actual equipment. Therefore, computational approach like the FE analysis has been considered. The FE analysis results are very sensitive to the FE model density and analysis conditions. In this paper the optimized FE model for the residual stress analysis will be developed in the case of CEDM penetration nozzle. The optimized parameters contains bead number and mesh density. The bead numbers along the longitudinal and circumferential directions are considered and the mesh density in each the bead is also considered. The model will be verified by numerical error control.


Author(s):  
I. Sladojevic´ ◽  
E. P. Petrov ◽  
M. Imregun ◽  
A. I. Sayma

The paper presents the results of a study looking into changes in the forced response levels of bladed disc assemblies subject to both structural and aerodynamic mistuning. A whole annulus FE model, representative of a civil aero-engine fan with 26 blades was used in the calculations. The forced response of all blades of 1000 random mistuned patterns was calculated. The aerodynamic parameters, frequency shifts and damping, were calculated using a three-dimensional Reynolds-averaged Navier-Stokes aero-elasticity code. They were randomly varied for each mistuning pattern, with the assumption that the system would remain stable, i.e. flutter would not occur due to aerodynamic mistuning. The results show the variation of the forced response with different types of mistuning, with structural mistuning only, with aerodynamic mistuning only and with both structural and aerodynamic mistuning.


2021 ◽  
Vol 143 (4) ◽  
Author(s):  
Serkan Kangal ◽  
A. Harun Sayı ◽  
Ozan Ayakdaş ◽  
Osman Kartav ◽  
Levent Aydın ◽  
...  

Abstract This paper presents a comparative study on the burst pressure performance of aluminum (Al) liner for type-III composite overwrapped pressure vessels (COPVs). In the analysis, the vessels were loaded with increasing internal pressure up to the burst pressure level. In the analytical part of the study, the burst pressure of the cylindrical part was predicted based on the modified von Mises, Tresca, and average shear stress criterion (ASSC). In the numerical analysis, a finite element (FE) model was established in order to predict the behavior of the vessel as a function of increasing internal pressure and determine the final burst. The Al pressure vessels made of Al-6061-T6 alloy with a capacity of 5 L were designed. The manufacturing of the metallic vessels was purchased from a metal forming company. The experimental study was conducted by pressurizing the Al vessels until the burst failure occurred. The radial and axial strain behaviors were monitored at various locations on the vessels during loading. The results obtained through analytical, numerical, and experimental work were compared. The average experimental burst pressure of the vessels was found to be 279 bar. The experimental strain data were compared with the results of the FE analysis. The results indicated that the FE analysis and ASSC-based elastoplastic analytical approaches yielded the best predictions which are within 2.2% of the experimental burst failure values. It was also found that the elastic analysis underestimated the burst failure results; however, it was effective for determining the critical regions over the vessel structure. The strain behavior of the vessels obtained through experimental investigations was well correlated with those predicted through FE analysis.


2018 ◽  
Vol 225 ◽  
pp. 03009 ◽  
Author(s):  
N.M.A. Azam ◽  
Rosdi Daud ◽  
H. Mas Ayu ◽  
J. Ramli ◽  
M.F.B. Hassan ◽  
...  

The effect of flexion angle on contact stress of the knee joint still open to the debate since lack of proof shown that flexion angles does effect the contact stress of Total Knee Arthroplasty (TKA). Thus the aim of this study is to investigate the effect of different flexion angle on contact stress of TKA via finite element method. The TKA is simulated using ANSYS Workbench and the applied loads are 2200 N, 3200 N and 2800 N. The Finite element Analysis (FEA) results for maximum stress of current and proposed designed were then compared. For the new proposed design, the maximum stress for 15° is 12.2 MPa, 45° is 23.6 MPa and 60° is 22.5 MPa which is lower than current design. Thus, it can be concluded that the new proposed design better than current design in term of contact stress. While, the different flexion angle do gives an impact on the performance of the TKA.


Author(s):  
Sourabh Shrivastava ◽  
Prem Andrade ◽  
Vinay Carpenter ◽  
Ravindra Masal ◽  
Pravin Nakod ◽  
...  

Abstract Better life assessment of hot-components of an aero-engine can help improve its reliability and service life, while, reducing associated maintenance cost. Accurate prediction of Thermo-Mechanical Fatigue (TMF) is one of the crucial aspects of life prediction. Therefore, fully resolved simulation methodologies have gained attention as an ingredient for solving TMF problems owing to their potential for providing comprehensive insights into a system having hot components undergoing transient loading during operation. The present work focuses on a multi-physics simulation-based approach for the life-prediction of a representative gas-turbine combustor liner with an objective of providing a complete framework for TMF analysis of an actual aero-engine combustor liner. The presented methodology consists of a coupling between Computational Fluid Dynamics (CFD) and Finite Element Method (FEM). Thermal loads on the representative aero-engine combustor are predicted using Conjugate Heat Transfer (CHT) modeling in the CFD analyses for different operating conditions suitable for a flight cycle. A load cycle is then constructed using these thermal loads and is transferred to the structural analysis to evaluate the stresses in the liner. Results are obtained regarding spatially varying thermal expansion resulting in inelastic strains as governed by temperature and rate dependent material behavior. Stress and plastic strain history information from the structural analysis are processed to predict the life of different regions of the combustor liner. Different simulation methods for conjugate heat-transfer, load-cycle, material property extraction, thermal-stresses, and fatigue are evaluated, and an overall methodology involving accuracy and reasonable computational cost is proposed. The proposed methodology is numerically verified, and the verification results are presented in this work.


Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1377 ◽  
Author(s):  
Thanh-Canh Huynh ◽  
So-Young Lee ◽  
Ngoc-Loi Dang ◽  
Jeong-Tae Kim

For impedance-based damage detection practices, the sensing range of piezoelectric devices is an important parameter that should be determined before real implementations. This study presents numerical and experimental analyses for characterizing the sensing region of a smart PZT (lead–zirconate–titanate) interface for damage monitoring in plate-like structures. First, a finite element (FE) model of the PZT interface mounted on a plate structure is established. The impedance responses of the PZT interface are numerically simulated under different damage locations inflicted in the plate domain. The impedance features are extracted from the impedance signatures to analyze the sensing distance and the damage detectability of the PZT interface. Next, the splice plate of a bolted connection is selected as a practical plate-like structure for the experimental examination of the PZT interface’s sensing region on a limited plate domain. The damage sensitivity behavior of the PZT interface is analyzed with respect to the damage location on the splice plate. An FE analysis of the corresponding PZT interface-splice plate system is also conducted to support the experimental results.


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