Hybrid Fatigue Analysis Method for Railway Carbody Structure

2008 ◽  
Vol 44-46 ◽  
pp. 733-738 ◽  
Author(s):  
Bing Rong Miao ◽  
Wei Hua Zhang ◽  
Shou Ne Xiao ◽  
Ding Chang Jin ◽  
Yong Xiang Zhao
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Hybrid Method ◽  
Dynamic Stress ◽  
Stress Test ◽  
Fatigue Analysis ◽  
Railway Vehicle ◽  
Analysis Method ◽  
Structure Dynamic ◽  
Multi Body

Railway vehicle structure fatigue life consumption monitoring can be used to determine fatigue damage by directly or indirectly monitoring the loads placed on critical vehicle components susceptible to failure from fatigue damage. The sample locomotive carbody structure was used for this study. Firstly, the hybrid fatigue analysis method was used with Multi-Body System (MBS) simulation and Finite Element Method (FEM) for evaluating the carbody structure dynamic stress histories. Secondly, the standard fatigue time domain method was used in fatigue analysis software FE-FATIGUE and MATLAB WAFO (Wave Analysis for Fatigue and Oceanography) tools. And carbody structure fatigue life and fatigue damage were predicted. Finally, and carbody structure dynamic stress experimental data was taken from this locomotive running between Kunming-Weishe for this analysis. The data was used to validate the simulation results based on hybrid method. The analysis results show that the hybrid method prediction error is approximately 30.7%. It also illustrates that the fatigue life and durability of the locomotive can be predicted with this hybrid method. The results of this study can be modified to be representative of the railway vehicle dynamic stress test.

In situ and experimental analysis of longitudinal load on carbody fatigue life using nonlinear damage accumulation

2021 ◽  
pp. 105678952110460
Author(s):  
Sunil Kumar Sharma ◽  
Rakesh Chandmal Sharma ◽  
Jaesun Lee
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Damage ◽  
Damage Accumulation ◽  
Dynamic Stress ◽  
Fatigue Analysis ◽  
Analysis Method ◽  
Accumulation Model ◽  
Longitudinal Load ◽  
Damage Accumulation Model

In this paper, a multi-disciplinary analysis method is proposed for evaluating the fatigue life of railway vehicle car body structure under random dynamic loads. Firstly, the hybrid fatigue analysis method was used with Multi-Body System simulation and finite element method for evaluating the carbody structure dynamic stress histories. The dynamics stress is calculated from the longitudinal load using longitudinal train dynamics. Secondly, the nonlinear damage accumulation model was used in fatigue analysis, and carbody structure fatigue life and fatigue damage were predicted. The mathematical model simulations are compared with results produced experimentally, showing good agreement. Finally, the mode is determined after the finite element model is established. To achieve the dynamic stress at each node, the modal response is used as excitation. The carbody damage was obtained by combining dynamics stress with the NMCCMF damage accumulation model. As a result, the effect of longitudinal load on carbody fatigue damage is investigated. The longitudinal load contributes significantly to the fatigue damage of the carbody.

The Application of AAR Load Spectrums in the Fatige Assessment for G70 Tank Carbody

2013 ◽  
Vol 690-693 ◽  
pp. 1960-1965 ◽  
Author(s):  
Sheng Qu ◽  
Ping Bo Wu ◽  
Zhuan Hua Liu
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Finite Element Model ◽  
Dynamic Stress ◽  
Element Model ◽  
Fatigue Analysis ◽  
Static Method ◽  
Analysis Method ◽  
Major Class ◽  
Calculated Stress

G70 Tank car uesd for transportation on liquidsliquids of gas and bulck goods in form of powder,is one of the major class of Chinese railroad freight cars.And the tank car makes about 18% of the toatal amount of freight cars. In this stduy, the carbdoy finite element model of tank car was constructed,and calculated stress of carbody both empty car and fully loaded car,then get the results of key postsitions. According to the AAR load spectrums on the part of the tank car,translated the results into dynamic stress through the quasi-static method. Calculated the damage of carbody with the fatigue analysis method provied in AAR, compared the fatigue life under various comonent.

A Shortcut Fatigue Analysis Method

1990 ◽  
Vol 112 (1) ◽  
pp. 1-5 ◽  
Author(s):  
H. M. Thompson
Keyword(s):  
Fatigue Life ◽  
Transfer Function ◽  
Fatigue Analysis ◽  
Analysis Method ◽  
Dynamic Amplification Factor ◽  
Single Degree Of Freedom ◽  
At Resonance ◽  
Order Of Magnitude ◽  
Dynamic Amplification ◽  
Good Agreement

A shortcut fatigue analysis method is presented which can be used to provide fatigue life estimates during the preliminary design phase of deepwater fixed platforms. For this type of structure, the method is intended to provide order of magnitude fatigue life estimates only. For simpler structures, such as deepwater offshore caissons, the shortcut analysis can provide good agreement with a detailed spectral fatigue analysis. The fundamental assumption of the method is that the dynamic transfer function can be closely approximated by the product of the static transfer function and a single degree of freedom dynamic amplification factor, which has been adjusted to produce a “fit” to the true DAF at resonance. Only one dynamic analysis of the structure needs to be performed, i.e., to determine the true DAF at resonance.

scholarly journals Umbilical Fatigue Analysis for a Wave Energy Converter

2020 ◽  
Author(s):  
Billy Ballard ◽  
Yi-Hsiang Yu ◽  
Jennifer Van Rij ◽  
Frederick Driscoll
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Wave Energy ◽  
Degrees Of Freedom ◽  
Oil And Gas ◽  
Time History ◽  
Fatigue Analysis ◽  
Offshore Wind ◽  
Wave Energy Converters ◽  
Energy Technologies

Abstract Unique umbilical designs for wave energy converters (WECs), including the ability to handle significantly larger motions and loads over long deployments, are often required when conventional marine umbilical designs for offshore oil and gas and offshore wind may not meet the design and cost needs of wave energy technologies. This study details a fatigue analysis of a dynamic power umbilical attached to a two-body floating point absorber WEC system, using the sea states provided for the PacWave testing facilities. The 6 degrees of freedom motion time history for the WEC was simulated, and the motions of the attachment point for the umbilical on the WEC and respective sea states were used to analyze the dynamic motions and fatigue of the connected power umbilical to predict the fatigue life. The results show that the fatigue damage observed is more significant in shallow water, and extensive fatigue damage may occur because of the larger curvature response of the umbilical. The umbilical configurations departing at 90 deg off incoming waves were found to have the highest fatigue life attributed to less extension or compression of the umbilical. However, additional bend stiffener/limiter features may need to be incorporated into the buoyancy section and touchdown regions to minimize curvature-induced fatigue.

scholarly journals A Multi-Scale Submodel Method for Fatigue Analysis of Braided Composite Structures

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4190
Author(s):  
Jincheng Zheng ◽  
Peiwei Zhang ◽  
Dahai Zhang ◽  
Dong Jiang
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Failure ◽  
Failure Criterion ◽  
Cell Model ◽  
Fatigue Analysis ◽  
Analysis Method ◽  
Shear Lag ◽  
Multi Scale ◽  
Meso Scale

A multi-scale fatigue analysis method for braided ceramic matrix composites (CMCs) based on sub-models is developed in this paper. The finite element shape function is used as the interpolation function for transferring the displacement information between the macro-scale and meso-scale models. The fatigue failure criterion based on the shear lag theory is used to implement the coupling calculation of the meso-scale and micro-scale. Combining the meso-scale cell model and the fatigue failure criterion based on the shear lag theory, the fatigue life of 2D SiC/SiC is analyzed. The analysis results are in good agreement with the experimental results, which proves the accuracy of the meso-scale cell model and the fatigue life calculation method. A multi-scale sub-model fatigue analysis method is used to study the fatigue damage of 2D SiC/SiC stiffened plates under random tension–tension loads. The influence of the sub-models at different positions in the macro-model element on the analysis results was analyzed. The results shows that the fatigue analysis method proposed in this paper takes into account the damage condition of the meso-structured of composite material, and at the same time has high calculation efficiency, and has low requirements for modeling of the macro finite element model, which can be better applied to the fatigue analysis of CMCs structure.

A Dynamic Simulation Approach to Machine Component Life Prediction

1988 ◽  
Author(s):  
T. S. Liu ◽  
E. J. Haug ◽  
B. Dopker
Keyword(s):  
Fatigue Life ◽  
Stress Analysis ◽  
Elastic Deformation ◽  
Life Prediction ◽  
Dynamic Stress ◽  
Subsequent Paper ◽  
Simulation Approach ◽  
Analysis Method ◽  
Deformation Method ◽  
Dynamic Stress Analysis

Abstract A system simulation approach is presented for dynamic stress analysis and life prediction of components of machines that undergo nonsteady gross motion and elastic deformation. The method employs finite element structural analysis, coupled gross motion-elastic deformation dynamics, and computer-based fatigue analysis, A computer aided engineering methodology is developed for life prediction by linking together software from dynamics, structures, and fatigue life estimation; to compliment conventional fatigue experiments. Dynamic stress analysis is carried out using either an uncoupled gross motion-elastic deformation method or a more accurate approach that takes into account the coupling between large displacements and elastic deformation. With the aid of vehicle operational scenarios, stress/strain histories at critical regions in vehicle components during a projected service life are simulated. A local strain approach is used to calculate cumulative fatigue damage at notches, which is used in assessing fatigue life of components during the design phase; i.e., prior to availability of experimental data A vehicle example is presented, using a simplified dynamic-stress analysis method. The more general and accurate fully coupled dynamic-stress analysis method will be illustrated in a subsequent paper.

A Hybrid Method for Determining the Dynamic Stresses of Railway Vehicle

2010 ◽  
Vol 118-120 ◽  
pp. 645-649
Author(s):  
Z. Tang ◽  
Ping Bo Wu ◽  
Zhu Yang
Keyword(s):  
Hybrid Method ◽  
Dynamic Stress ◽  
Superposition Principle ◽  
Normal Modes ◽  
Time History ◽  
Railway Vehicle ◽  
Strain Response ◽  
Dynamic Stresses ◽  
Modes Of Vibration ◽  
Modal Coordinates

On the basis of the idea that the displacement response of the structure can be expressed as superposition of normal modes of vibration multiplied by corresponding time-dependent modal coordinate, the strain response of the same structure under the same loading condition can also be regarded as a superposition of strain modes multiplied by modal coordinates, this paper presents a hybrid method for determining the dynamic stresses of railway vehicle based on the combination of experiment and numerical simulation. The calculation formulas based on strain mode superposition principle is deduced in detail. The numerical experiment shows that the dynamic stress time history can be obtained by the proposed method expediently and accurately. In addition, to meet the demand of fatigue engineer of the vehicle bogie, a software system was developed, which has a friendly, open and easily removable interface and is valuable for practical use.

Automated Identification of Critical Tubular Joints of Offshore Jacket Structure by Deterministic Fatigue Analysis

2017 ◽  
Author(s):  
Shrikarpagam Dhandapani
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Hot Spot ◽  
Offshore Structures ◽  
Fatigue Analysis ◽  
Optimized Design ◽  
Base Shear ◽  
Hot Spot Stress ◽  
Environmental Loads ◽  
Tubular Joints

Fatigue occurs in structures due to the stresses from cyclic environmental loads. Offshore environmental loads being highly cyclic and recurring in nature, fatigue analysis with high degree of accuracy is required for reliable and optimized design of offshore structures. The main aim of this paper is to automate the process of identification of fatigue critical tubular joints of an offshore jacket structure using deterministic fatigue analysis with emphasis on the Hot Spot Stress Range (HSSR), an important measure in estimating fatigue damage, calculated using three different approaches for each tubular joint. The first approach determines HSSR at the time of maximum base shear of the jacket, the second, by calculating the difference between maximum and minimum Hot Spot Stress (HSS) and the third, at all time-instants of the wave cycle. Thus fatigue damage and fatigue life of the tubular joints are estimated using the highest HSSR value and the joints with lower fatigue life are identified as fatigue sensitive joints. This ensures effective identification of critical tubular joints of the offshore jacket structure which needs detailed investigation or redesign for fatigue. The deterministic approach discussed in this paper is applicable to large jackets which contains more number of tubular joints where sophisticated fatigue assessment at the preliminary stage is computationally intensive and manual identification of fatigue critical joints is laborious.

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