Fatigue Life Prediction Using Frequency Response Functions

1992 ◽  
Vol 114 (3) ◽  
pp. 381-386 ◽  
Author(s):  
K. Y. Sanliturk ◽  
M. Imregun
Keyword(s):  
Fatigue Life ◽  
Frequency Response ◽  
Vibration Analysis ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Dynamic Loads ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Crack Position

This paper presents a method for fatigue life prediction of engineering components subjected to dynamic loads. It is based on the determination of the nominal stress at the crack position using frequency response functions and this in turn enables the prediction of dynamic fatigue life under forced vibration. The main advantage of this approach lies in the fact that stresses used for fatigue life prediction are determined via a vibration analysis and hence not only elastic but also inertia and damping forces are included in the model. The implementation of the technique is discussed in the case of a bladed-disc assembly where single-blade mistuning is caused by a fatigue crack. It is believed that the proposed method has promising implications for safer designs and also for the prediction of inspection intervals, especially in rotating machinery applications where such considerations are of paramount importance.

Fatigue Life Prediction of a Railway Bogie under Dynamic Loads through Simulation

1998 ◽  
Vol 29 (6) ◽  
pp. 385-402 ◽  
Author(s):  
STEFAN DIETZ ◽  
HELMUTH NETTER ◽  
DELF SACHAU
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Dynamic Loads ◽  
Railway Bogie

Fatigue-life prediction under irregular stress conditions

1970 ◽  
Vol 5 (3) ◽  
pp. 207-211 ◽  
Author(s):  
T H Erismann
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Stress Conditions ◽  
Fatigue Life Prediction ◽  
Mean Stress ◽  
Arbitrary Loading ◽  
Empirical Determination ◽  
The Mean ◽  
Standard Tests

The present work is a shorter version of a more detailed treatise by the author (1)∗. The method consists of two parts: the empirical determination of certain characteristics of a material by means of a relatively small number of well defined standard tests, and the arithmetical application of the results obtained to arbitrary loading histories. The following groups of parameters are thus taken into account: the variations of the mean stress; the interaction of these variations and the superposed oscillating stresses; the spectrum of the oscillating-stress amplitudes; the sequence of the oscillating-stress amplitudes.

Fatigue Life Predictions by Coupling Finite Element and Multibody Systems Calculations

1997 ◽  
Author(s):  
Stefan Dietz ◽  
Helmuth Netter ◽  
Delf Sachau
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Elastic Body ◽  
Multibody Systems ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Dynamic Loads ◽  
Multibody Simulation ◽  
Bogie Frame ◽  
Life Predictions

Abstract The dynamic loads and accelerations acting on a railway bogie are predicted by multibody simulation. The bogie frame is considered as an elastic body of the MBS-model, in which elastic displacements are represented by eigen and staticmodes. Stresses are calculated for the most stressed locations of a bogie in the MBS-postprocessor. Based on these a fatigue life prediction is carried out.

Research on Fatigue Life Prediction of Planetary Cage in Caterpillar Base on Running Simulation Test

2012 ◽  
Vol 226-228 ◽  
pp. 862-866 ◽  
Author(s):  
Xiu Ju Du ◽  
Chang Zhi Jia ◽  
Jing Wu
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Working Condition ◽  
Technical Problem ◽  
Fatigue Life Prediction ◽  
Dynamic Loads ◽  
Strength Theory ◽  
Simulation Test ◽  
Work Condition ◽  
Study Case

Planetary cage in caterpillar is designed with the static strength theory. While the dynamic characteristics of planetary parts in different working condition is difficult to obtain with the limit of traditional method, so research on reliability and fatigue life prediction of planetary cage is very difficulty which result that designed life is much longer than practical life. The reliability of caterpillar is affected deeply. The dynamic loads suffered by planetary cage in different working condition is obtained based on running simulation with MSC.ATV, and then the fatigue life of planetary frame is calculated with fatigue life prediction system of planetary cage. The study case proves the new method is feasible. Research on planetary cage in caterpillar based on running simulation test resolve not only the technical problem of loads in different work condition but also close connection with engineer, so the research have very important utility significance.

Integrated Computational Durability Analysis

1993 ◽  
Vol 115 (4) ◽  
pp. 492-499 ◽  
Author(s):  
W. K. Baek ◽  
R. I. Stephens ◽  
B. Dopker
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Life Prediction ◽  
Dynamic Stress ◽  
Local Strain ◽  
Fatigue Life Prediction ◽  
Dynamic Loads ◽  
Finite Element Stress Analysis ◽  
Multibody Dynamic ◽  
Crack Initiation Life

A computer aided analysis method is described for durability assessment in the early design stages using multibody dynamic analysis, finite element stress analysis, and fatigue life prediction methods. From multibody dynamic analysis of a mechanical system, dynamic loads of a mechanical component were calculated. Finite element stress analysis with substructuring techniques produced accurate stress fields for the component. From the dynamic loads and the stress field of the component, a dynamic stress history at the critical location was produced using the superposition principle. Using Neuber’s rule, a local strain time history was produced from the dynamic stress history. The local strain based fatigue life prediction method was then used to predict “crack initiation” life of the critical component. The predicted fatigue crack initiation life was verified by experimental durability tests. This methodology can be combined with identification of weak links and optimization techniques such that the design optimization for an entire mechanical system based upon durability is possible during the early product development stage.

Research on Fatigue Life Prediction of Gear Box in Caterpillar Based on Running Simulation Test

2012 ◽  
Vol 226-228 ◽  
pp. 627-631 ◽  
Author(s):  
Zhao Wei Dong ◽  
Jing Wu ◽  
Xiu Ju Du
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Working Condition ◽  
Fatigue Life Prediction ◽  
Dynamic Loads ◽  
Prediction System ◽  
Strength Theory ◽  
Simulation Test ◽  
Study Case ◽  
Gear Box

Gear box in caterpillar is designed with the static strength theory. While the dynamic characteristics of planetary parts in different working condition is difficult to obtain with the limit of traditional method, so research on reliability and fatigue life prediction of gear box is very difficulty which result that designed life is much longer than practical life. The reliability of caterpillar is affected deeply. The dynamic loads suffered by gear box in different working condition is obtained based on running simulation with MSC.ATV, and then the fatigue life of planetary frame is calculated with fatigue life prediction system of gear box. The study case prove the new method is feasible.

scholarly journals Calculation of Characteristics Describing the Properties of Dynamical Systems

2017 ◽  
Vol 17 (1) ◽  
pp. 147-154
Author(s):  
Jozef Melcer ◽  
Daniela Kuchárová ◽  
Mária Kúdelčíková
Keyword(s):  
Dynamical Systems ◽  
Computational Model ◽  
Frequency Response ◽  
Natural Frequencies ◽  
Dynamical Response ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Natural Modes ◽  
Selection Of

Abstract There are characteristics that uniquely define the properties of dynamical systems from the point of its dynamical response. For example, natural frequencies and natural modes or frequency response functions can be assigned to these characteristics. Determination of these characteristics is fixed on the selection of computational model and on the means of structure excitation. This contribution discusses about analysis of such characteristics.

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