Fatigue damage detection and prediction of fatigue life on a cantilever beam

2017 ◽  
Vol 8 (6) ◽  
pp. 648-655
Author(s):  
Manuel L. Aenlle ◽  
F. Pelayo ◽  
Alfonso Fernandez-Canteli
Keyword(s):  
Fatigue Life ◽  
Modal Analysis ◽  
Cantilever Beam ◽  
Fatigue Damage ◽  
Structural Engineering ◽  
Dynamic Properties ◽  
Element Model ◽  
Experimental Results ◽  
Content Type ◽  
Eurocode 3

Purpose Fatigue failure is an important criterion to be considered in the design of structures and mechanical components. Catastrophic failure of structures in service conditions can be avoided using adequate techniques to detect and localize fatigue damage. Modal analysis is a tool used in mechanical and structural engineering to estimate dynamic properties and also to monitor the health of structures. If modal analysis is applied periodically to a structure, fatigue damage can be detected and localized and the fatigue life can be extended by means of suitable reinforcement and repairing. The paper aims to discuss these issues. Design/methodology/approach The experimental results corresponding to the fatigue tests carried out on a steel S-275 cantilever beam are presented. Operational modal analysis was applied periodically to the beam in order to study the variation of modal parameters during the tests and the stresses were estimated combining a numerical model and the acceleration modal coordinates measured at discrete points of the structure. The experimental results are compared with those predicted applying the S-N model of Eurocode 3. Findings A methodology that combines a finite element model and the experimental responses of a structure has been applied to estimate the stress time histories of a cantilever beam clamped to a foundation through a steel plate. The estimated stresses have been used to predict the fatigue damage according to the Eurocode 3. Due to the fact that no information of the scatter is provided by this code (EC3), only the number of cycles corresponding to a probability of failure of 5 percent can be predicted. Originality/value The proposed methodology can be applied to real structures in order to know the accumulated fatigue damage in real time.

Experimental and Numerical Analyses of a Head Arm Assembly of a Micro-Drive

2006 ◽  
Vol 326-328 ◽  
pp. 1585-1588
Author(s):  
B.J. Shi ◽  
Dong Wei Shu ◽  
J. Luo ◽  
Q.Y. Ng ◽  
J.H.T. Lau
Keyword(s):  
Finite Element ◽  
Dynamic Properties ◽  
Dynamic Performance ◽  
Hard Disk Drives ◽  
Element Model ◽  
Information Storage ◽  
Experimental Results ◽  
Disk Drives ◽  
Element Simulation ◽  
Important Means

Hard disk drives (HDD) are now the most important means of information storage, and they continue to be made smaller in size, higher in capacity, and lower in cost. The dynamic performance of an HDD has been an increasingly important consideration for its design, as we move forward toward its consumer applications. The dynamic properties of the head arm assembly (HAA) of a micro-drive were investigated using both experimental and numerical techniques. A finite element model for studying the dynamic property of the HAA was created and modified according to the experimental results. Good correlation between the experimental results and those by finite element simulation was achieved.

scholarly journals Parameter identification for a point-supported cross laminated timber slab based on experimental and numerical modal analysis

2020 ◽  
Author(s):  
Michael Kawrza ◽  
Thomas Furtmüller ◽  
Christoph Adam ◽  
Roland Maderebner
Keyword(s):  
Modal Analysis ◽  
Model Updating ◽  
Dynamic Properties ◽  
Element Model ◽  
Mode Shapes ◽  
Cross Laminated Timber ◽  
Numerical Studies ◽  
Robust Parameter ◽  
Updating Procedure ◽  
Sensor Positions

AbstractIn this paper, the dynamic properties of a point-supported cross-laminated timber slab are studied in order to determine the elastic material parameters on this basis. A detailed experimental modal analysis of the slab with dimensions 16.0 m x 11.0 m is performed, and seven modes including the natural frequencies, damping ratios and mode shape components at 651 sensor positions are identified. The found mode shapes are complex due to environmental influences that occurred during the two-day measurement campaign. This error is corrected by eliminating these influences. A finite element model of the slab is presented, whose parameters in terms of material properties and boundary conditions are determined by a model updating procedure. Based on the modal properties of the seven experimentally identified modes, an accurate and robust parameter set is obtained, which can be used in further numerical studies of the considered CLT to check serviceability limit criteria.

Study on Modal Analysis for Motorcycle Frame by CAE Method

2014 ◽  
Vol 496-500 ◽  
pp. 601-604
Author(s):  
Jing Wang ◽  
Yong Wang ◽  
Ying Hua Liao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Experimental Method ◽  
Dynamic Properties ◽  
Element Model ◽  
Analytic Method ◽  
Motorcycle Frame ◽  
The Finite Element Model ◽  
Good Agreement

In this paper, the modal of motorcycle frame is analyzed by using the analytic method and experimental method. The results show that the dynamic properties of the finite element model are in good agreement with the experiment and the finite element model was reliable and accurate.

Early Fatigue Damage of Magnesium Alloy On-Line Monitoring by Nonlinear Ultrasonic

2010 ◽  
Vol 139-141 ◽  
pp. 194-197
Author(s):  
Bing Sheng Yan ◽  
Bin Wu ◽  
Cun Fu He ◽  
Jing Pin Jiao
Keyword(s):  
Fatigue Life ◽  
Magnesium Alloy ◽  
Yield Stress ◽  
Fatigue Damage ◽  
Stress Level ◽  
Second Harmonic ◽  
Experimental Results ◽  
Nonlinearity Parameter ◽  
Acoustic Nonlinearity Parameter ◽  
On Line

This research develops a robust experimental procedure to monitor the evolution of early fatigue damage in AZ31 magnesium alloy with the acoustic nonlinearity parameter , and demons- trats its reliability by measuring the linear relationship between amplitudes of the second-harmonic waves and fundamental waves squared. Using this system, of two sets of specimens with different stress level is measured. The experimental results show that there is a significant increase in linked to fatigue degree in the early stages of fatigue life and reaches the maximum about 55%of fatigue life, when the stress level is ±60%of the yield stress, can characterize the early fatigue damage of magnesium alloy. However, when the stress level is ±70%of the yield stress, there is a regular fluctuation in linked to fatigue degree, this experimental results can’t be explained.

scholarly journals Seismic Assessment in a Historical Masonry Minaret by Linear and Non-linear Seismic Analyses

2020 ◽  
Author(s):  
Emin Hökelekli ◽  
Ali Demir ◽  
Emre Ercan ◽  
Halil Nohutçu ◽  
Abdurrahman Karabulut
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Dynamic Properties ◽  
Ground Motions ◽  
Element Model ◽  
Operational Modal Analysis ◽  
Finite Element Models ◽  
Non Linear ◽  
Concrete Damage ◽  
Historical Masonry

Operational Modal Analysis (OMA) method is frequently used in order to determine dynamical properties of historical masonry structures. In this study, damage pattern of historical Alaca minaret which is selected as application is investigated under different ground motions by updating finite element models (FEM) depending on operational modal analysis test. Initial Finite element model was prepared in ABAQUS V10 program and numerical dynamic characteristics of minaret were determined. In addition, experimental dynamic properties of minaret were provided by operational modal analysis. Initial numerical model of brick masonry structure was calibrated via OMA method. Then, linear and non-linear seismic analyses of calibrated FEM of historical minaret were performed by using different earthquakes acceleration records that occurred in Turkey. Concrete Damage Plasticity model was taken into account in non-linear seismic analyses. As a result of the analyses, it is concluded that the stresses obtained with linear analyses aren’t as realistic as the non-linear analyses results and the earthquakes can cause some damages in the minaret.  

Accelerating the fatigue analysis based on strain signal using Hilbert–Huang transform

2019 ◽  
Vol 10 (1) ◽  
pp. 118-132
Author(s):  
Nadia Nurnajihah M. Nasir ◽  
Salvinder Singh ◽  
Shahrum Abdullah ◽  
Sallehuddin Mohamed Haris
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Low Frequency ◽  
Life Assessment ◽  
Distribution Analysis ◽  
Original Signal ◽  
Damage Potential ◽  
Content Type ◽  
Hilbert Huang Transform ◽  
Time Frequency

Purpose The purpose of this paper is to present the application of Hilbert–Huang transform (HHT) for fatigue damage feature characterisation in the time–frequency domain based on strain signals obtained from the automotive coil springs. Design/methodology/approach HHT was employed to detect the temporary changes in frequency characteristics of the vibration response of the signals. The extraction successfully reduced the length of the original signal to 40 per cent, whereas the fatigue damage was retained. The analysis process for this work is divided into three stages: signal characterisation with the application of fatigue data editing (FDE) for fatigue life assessment, empirical mode decomposition with Hilbert transform, an energy–time–frequency distribution analysis of each intrinsic mode function (IMF). Findings The edited signal had a time length of 72.5 s, which was 40 per cent lower than the original signal. Both signals were retained statistically with close mean, root-mean-square and kurtosis value. FDE improved the fatigue life, and the extraction did not affect the content and behaviour of the original signal because the editing technique only removed the minimal fatigue damage potential. HHT helped to remove unnecessary noise in the recorded signals. EMD produced sets of IMFs that indicated the differences between the original signal and mean of the signal to produce new components. The low-frequency energy was expected to cause large damage, whereas the high-frequency energy will cause small damage. Originality/value HHT and EMD can be used in the strain data signal analysis of the automotive component of a suspension system. This is to improve the fatigue life, where the extraction did not affect the content and behaviour of the original signal because the editing technique only removed the minimal fatigue damage potential.

The Effect of Seabottom Proximity of the Vortex-Induced Vibrations and Fatigue Life of Offshore Pipelines

1983 ◽  
Vol 105 (4) ◽  
pp. 464-468 ◽  
Author(s):  
D. T. Tsahalis
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Experimental Results ◽  
Offshore Pipelines ◽  
Vortex Induced Vibrations

The effect of the seabottom proximity on the vortex-induced vibrations of suspended spans of offshore pipelines is discussed in the light of recent relevant experimental results. It is shown that the effect of the seabottom proximity is to drastically alter the vortex-induced vibrations of supsended spans resulting into longer fatigue lives or equivalently longer safe lengths. A “generalized” fatigue damage is formulated universally applicable to all suspended spans.

scholarly journals Identification of Historical Veziragasi Aqueduct Using the Operational Modal Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
E. Ercan ◽  
A. Nuhoglu
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Model Updating ◽  
Dynamic Properties ◽  
Dynamic Test ◽  
Element Model ◽  
Operational Modal Analysis ◽  
Modal Identification ◽  
Ambient Vibration ◽  
Mode Shapes

This paper describes the results of a model updating study conducted on a historical aqueduct, called Veziragasi, in Turkey. The output-only modal identification results obtained from ambient vibration measurements of the structure were used to update a finite element model of the structure. For the purposes of developing a solid model of the structure, the dimensions of the structure, defects, and material degradations in the structure were determined in detail by making a measurement survey. For evaluation of the material properties of the structure, nondestructive and destructive testing methods were applied. The modal analysis of the structure was calculated by FEM. Then, a nondestructive dynamic test as well as operational modal analysis was carried out and dynamic properties were extracted. The natural frequencies and corresponding mode shapes were determined from both theoretical and experimental modal analyses and compared with each other. A good harmony was attained between mode shapes, but there were some differences between natural frequencies. The sources of the differences were introduced and the FEM model was updated by changing material parameters and boundary conditions. Finally, the real analytical model of the aqueduct was put forward and the results were discussed.

Modal Analysis of Helical Milling Unit

2012 ◽  
Vol 482-484 ◽  
pp. 2454-2459 ◽  
Author(s):  
Xu Da Qin ◽  
Cui Lu ◽  
Qi Wang ◽  
Hao Li ◽  
Lin Jing Gui
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Dynamic Properties ◽  
Three Dimensional ◽  
Element Model ◽  
Helical Milling ◽  
Mode Shapes ◽  
Three Dimensional Model ◽  
Working Principle ◽  
The Finite Element Model

Based on the analysis of the working principle and structure characteristics of helical milling unit, the prototype’s three-dimensional model was built, the prototype’s finite element modal analysis was conducted, and the first 6 natural frequencies and their mode shapes were obtained. The finite element model is experimentally validated by comparing finite element and experimental modal’s parameters. This paper investigates the dynamic properties of prototype, and provides theoretical references for the subsequent dynamic analysis and structural optimization.

Contact fatigue life prediction of rolling bearing considering machined surface integrity

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Li Cui ◽  
Yin Su
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Fatigue Failure ◽  
Surface Integrity ◽  
Damage Accumulation ◽  
Rolling Bearing ◽  
Content Type ◽  
Accumulation Model ◽  
Fatigue Damage Accumulation ◽  
Damage Accumulation Model

Purpose Rolling bearings often cause engineering accidents due to early fatigue failure. The study of early fatigue failure mechanism and fatigue life prediction does not consider the integrity of the bearing surface. The purpose of this paper is to find new rolling contact fatigue (RCF) life model of rolling bearing. Design/methodology/approach An elastic-plastic finite element (FE) fatigue damage accumulation model based on continuous damage mechanics is established. Surface roughness, surface residual stress and surface hardness of bearing rollers are considered. The fatigue damage and cumulative plastic strain during RCF process are obtained. Mechanism of early fatigue failure of the bearing is studied. RCF life of the bearing under different surface roughness, hardness and residual stress is predicted. Findings To obtain a more accurate calculation result of bearing fatigue life, the bearing surface integrity parameters should be considered and the elastic-plastic FE fatigue damage accumulation model should be used. There exist the optimal surface parameters corresponding to the maximum RCF life. Originality/value The elastic-plastic FE fatigue damage accumulation model can be used to obtain the optimized surface integrity parameters in the design stage of bearing and is helpful for promote the development of RCF theory of rolling bearing.

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