scholarly journals A numerical approach to evaluate the fatigue life of monolimb

2006 ◽  
Vol 28 (3) ◽  
pp. 290-296 ◽  
Author(s):  
Nian-Zhong Chen ◽  
Winson C.C. Lee ◽  
Ming Zhang
Keyword(s):  
Fatigue Life ◽  
Numerical Approach

Aeromechanical Modeling of Rotating Fan Blades to Investigate High-Cycle and Low-Cycle Fatigue Interaction

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Priyanka Dhopade ◽  
Andrew J. Neely
Keyword(s):  
Fatigue Life ◽  
Fracture Mechanics ◽  
Low Cycle Fatigue ◽  
Numerical Approach ◽  
Combined Loading ◽  
Design Stage ◽  
Cycle Fatigue ◽  
Mechanics Analysis ◽  
The Individual ◽  
Loading Spectrum

Gas turbine engine components are subject to both low-cycle fatigue (LCF) and high-cycle fatigue (HCF) loads. To improve engine reliability, durability and maintenance, it is necessary to understand the interaction of LCF and HCF in these components, which can adversely affect the overall life of the engine while they are occurring simultaneously during a flight cycle. A fully coupled aeromechanical fluid–structure interaction (FSI) analysis in conjunction with a fracture mechanics analysis was numerically performed to predict the effect of representative fluctuating loads on the fatigue life of blisk fan blades. This was achieved by comparing an isolated rotor (IR) to a rotor in the presence of upstream inlet guide vanes (IGVs). A fracture mechanics analysis was used to combine the HCF loading spectrum with an LCF loading spectrum from a simplified engine flight cycle in order to determine the extent of the fatigue life reduction due to the interaction of the HCF and LCF loads occurring simultaneously. The results demonstrate the reduced fatigue life of the blades predicted by a combined loading of HCF and LCF cycles from a crack growth analysis, as compared to the effect of the individual cycles. In addition, the HCF aerodynamic forcing from the IGVs excited a higher natural frequency of vibration of the rotor blade, which was shown to have a detrimental effect on the fatigue life. The findings suggest that FSI, blade–row interaction and HCF/LCF interaction are important considerations when predicting blade life at the design stage of the engine. The lack of available experimental data to validate this problem emphasizes the utility of a numerical approach to first examine the physics of the problem and second to help establish the need for these complex experiments.

scholarly journals Fatigue Life Assessment for Power Cables in Floating Offshore Wind Turbines

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3096
Author(s):  
Mohsen Sobhaniasl ◽  
Francesco Petrini ◽  
Madjid Karimirad ◽  
Franco Bontempi
Keyword(s):  
Fatigue Life ◽  
Wind Waves ◽  
Numerical Approach ◽  
Life Assessment ◽  
Offshore Wind ◽  
Numerical Code ◽  
Offshore Wind Turbine ◽  
Commercial Code ◽  
Floating Offshore Wind Turbines ◽  
Combined Action

In this paper, a procedure is proposed to determine the fatigue life of the electrical cable connected to a 5 MW floating offshore wind turbine, supported by a spar-buoy at a water depth of 320 m, by using a numerical approach that takes into account site-specific wave and wind characteristics. The effect of the intensity and the simultaneous actions of waves and wind are investigated and the outcomes for specific cable configurations are shown. Finally, the fatigue life of the cable is evaluated. All analyses have been carried out using the Ansys AQWA computational code, which is a commercial code for the numerical investigation of the dynamic response of floating and fixed marine structures under the combined action of wind, waves and current. Furthermore, this paper applies the FAST NREL numerical code for comparison with the ANSYS AQWA results.

scholarly journals Numerical fatigue life estimation of aluminium 6201-T81 wires containing geometric discontinuities.

2018 ◽  
Vol 165 ◽  
pp. 10015
Author(s):  
Jesús Martínez ◽  
Vitor Adriano ◽  
José Araújo ◽  
Jorge Ferreira ◽  
Cosme da Silva
Keyword(s):  
Experimental Study ◽  
Fatigue Life ◽  
Numerical Approach ◽  
Critical Distance ◽  
Partial Slip ◽  
Life Estimation ◽  
Slip Regime ◽  
Fatigue Life Estimation ◽  
Geometric Discontinuities ◽  
Through Hole

Previous works have shown that fretting fatigue can be modelled as a notch problem due to the mild superficial damage produced in the partial slip regime during fretting. In this context, the aim of this numerical and experimental study is to estimate the fatigue life of aluminium 6201-T81 wires, used in overhead conductors, containing geometric discontinuities. These discontinuities induce a stress field analogous to the fretting problem. To perform the fatigue life assessments the LM-Nf relationship, which is an extension of the Theory of Critical Distance (TCD), was applied. The LM-Nf relationship was calibrated using two S-N curves, one of a plain wire and other of a notched wire. The validation of the numerical approach estimations was performed using a wire containing a through hole. The estimations were fallen almost entirely among factor 3 bands when compared with the experimental results. This factor 3 represents the biggest scatter in the S-N curves used to calibrate the LM-Nf relation. The TCD approach applied, in terms of point method, provide accurate life estimations in the range 105 and 106 cycles.

Comparative study of adhesive fatigue in aeronautical bonded joints: A numerical approach in the frequency domain

2021 ◽  
pp. 146442072110500
Author(s):  
Denys Marques ◽  
Marcelo L Ribeiro ◽  
Volnei Tita
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Adhesive Layer ◽  
Numerical Approach ◽  
Bonded Joints ◽  
Cohesive Failure ◽  
Adhesively Bonded ◽  
Random Loads ◽  
Bonded Joint ◽  
Adhesively Bonded Structures

The use of adhesively bonded structures has increased over the years, together with the development of composite materials. This work investigates a procedure for fatigue life prediction of an aeronautical bonded joint under random loads, in particular, the cohesive failure of the adhesive layer in a skin-to-stiffener bonded joint. The use of two different adhesives is investigated, and Dirlik’s method is employed to predict the stress response in the adhesive layer, from which the fatigue life is obtained. The effect of damping is also investigated, and it is shown that increases in damping result in higher fatigue life estimations.

Fatigue Life of Superelastic Springs for an Anterior Cruciate Ligament Prosthesis

1995 ◽  
Vol 05 (C8) ◽  
pp. C8-1223-C8-1228
Author(s):  
N. Hagemeister ◽  
L'H. Yahia ◽  
E. Weynant ◽  
T. Lours
Keyword(s):  
Anterior Cruciate Ligament ◽  
Fatigue Life ◽  
Cruciate Ligament ◽  
Anterior Cruciate ◽  
Ligament Prosthesis

Modification of MnS inclusion by tellurium in 38MnVS6 micro-alloyed steel

2020 ◽  
Vol 117 (6) ◽  
pp. 615
Author(s):  
Ping Shen ◽  
Lei Zhou ◽  
Qiankun Yang ◽  
Zhiqi Zeng ◽  
Kenan Ai ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Aspect Ratio ◽  
Strong Influence ◽  
Experimental Results ◽  
Alloyed Steel ◽  
Equivalent Diameter ◽  
Small Aspect Ratio ◽  
Steel Quality ◽  
Eds Analysis ◽  
Micro Alloyed Steel

In 38MnVS6 steel, the morphology of sulfide inclusion has a strong influence on the fatigue life and machinability of the steel. In most cases, the MnS inclusions show strip morphology after rolling, which significantly affects the steel quality. Usually, the MnS inclusion with a spherical morphology is the best morphology for the steel quality. In the present work, tellurium was applied to 38MnVS6 micro-alloyed steel to control the MnS inclusion. Trace tellurium was added into 38MnVS6 steel and the effect of Te on the morphology, composition, size and distribution of MnS inclusions were investigated. Experimental results show that with the increase of Te content, the equivalent diameter and the aspect ratio of inclusion decrease strikingly, and the number of inclusions with small aspect ratio increases. The inclusions are dissociated and spherized. The SEM-EDS analysis indicates that the trace Te mainly dissolves in MnS inclusion. Once the MnS is saturated with Te, MnTe starts to generate and wraps MnS. The critical Te/S value for the formation of MnTe in the 38MnV6 steel is determined to be approximately 0.075. With the increase of Te/S ratio, the aspect ratio of MnS inclusion decreases and gradually reaches a constant level. The Te/S value in the 38MnVS6 steel corresponding to the change of aspect ratio from decreasing to constant ranges from 0.096 to 0.255. This is most likely to be caused by the saturation of Te in the MnS inclusion. After adding Te in the steel, rod-like MnS inclusion is modified to small inclusion and the smaller the MnS inclusion, the lower the aspect ratio.

Method of Calculating the Fatigue Life of Bearings Taking into Account Wearing of Rolling Elements

2020 ◽  
Vol 41 (4) ◽  
pp. 491-497
Author(s):  
V. B. Balyakin ◽  
◽  
E.P Zhilnikov ◽  
K. K Pilla ◽  
◽  
...  
Keyword(s):  
Fatigue Life ◽  
Rolling Elements
Sign in / Sign up

Export Citation Format

Share Document