Fatigue Damage of a Cutter Used for Cutting Cashew Nut under Random Load

2015 ◽  
Vol 743 ◽  
pp. 49-54
Author(s):  
Y.F. Fu ◽  
J. Gong ◽  
D.M. Zhu ◽  
Y.J. Liu ◽  
Hui Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fatigue Damage ◽  
Equivalent Stress ◽  
Time History ◽  
Post Processing ◽  
Load Spectrum ◽  
Random Load ◽  
Cashew Nut ◽  
History Of ◽  
Processing Software

To study the fatigue damage of a cutter used for cutting cashew nut, the integrated<br />simulation platform is established with Hypermesh, LS-Dyna, LS-PrePost, and nCode GlyphWorks.<br />The simulation model is established by Hypermesh. LS-Dyna is used to calculate the k file.<br />LS-PrePost is used as the post-processing software. The rain-flow counting, load superposition and<br />extrapolation are executed using Rainflow module in nCode GlyphWorks. The analysis of the<br />fatigue damage of the cutter is executed using Stress Life module in nCode GlyphWorks. The<br />equivalent stress time history of different elements in the upper and lower cutters, rain-flow<br />counting histogram after load spectrum superposition, rain-flow counting histograms after load<br />spectrum extrapolation, and damage histogram of the cutter are obtained. The results show that the<br />cutter has excellent mechanical properties, and the minimum fatigue life of the cutter is about 495<br />days, which is a conservative solution.

scholarly journals Prediction of Fatigue Life of a Continuous Bridge Girder Based on Vehicle Induced Stress History

2003 ◽  
Vol 10 (5-6) ◽  
pp. 325-338 ◽  
Author(s):  
V.G. Rao ◽  
S. Talukdar
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Fatigue Testing ◽  
Damage Index ◽  
Time History ◽  
Stress Range ◽  
Frequency Histogram ◽  
Bridge Span ◽  
History Of ◽  
Bridge Girder

The fatigue damage assessment of bridge components by conducting a full scale fatigue testing is often prohibitive. A need, therefore, exists to estimate the fatigue damage in bridge components by a simulation of bridge-vehicle interaction dynamics due to the action of the actual traffic. In the present paper, a systematic method has been outlined to find the fatigue damage in the continuous bridge girder based on stress range frequency histogram and fatigue strength parameters of the bridge materials. Vehicle induced time history of maximum flexural stresses has been obtained by Monte Carlo simulation process and utilized to develop the stress range frequency histogram taking into consideration of the annual traffic volume. The linear damage accumulation theory is then applied to calculate cumulative damage index and fatigue life of the bridge. Effect of the bridge span, pavement condition, increase of vehicle operating speed, weight and suspension characteristics on fatigue life of the bridge have been examined.

Reliability Assessment of Fatigue Life of Hangers in Large-Span Suspension Bridges

2011 ◽  
Vol 147 ◽  
pp. 149-152
Author(s):  
Yong Zeng ◽  
Hong Mei Tan
Keyword(s):  
Time History ◽  
Public Confidence ◽  
Suspension Bridges ◽  
Fatigue Reliability ◽  
Load Spectrum ◽  
Accurate Analysis ◽  
Vehicle Load ◽  
History Of ◽  
Vehicle Loads ◽  
Main Cables

Hangers are very important components for suspension bridges, which link main cables and stiffening girders. When in service, hangers are much vulnerable to fatigue loads due to kinds of traffic flows, which may reduce the remaining life of the hangers and increase the risk of losing public confidence in cable supported bridges. In order to quantify the reliability of hangers under vehicle loads, fatigue reliability formula of hangers is proposed in this paper. Based on the accurate analysis of vehicle load spectrum, the time history of hangers is simulated and maintenance strategy is proposed.

Statistical Analysis of Loader’s Drive Axle Housing Random Load Spectrum

2011 ◽  
Vol 338 ◽  
pp. 456-459 ◽  
Author(s):  
Bu Zheng Wen ◽  
Jian Min Li ◽  
Zhong Tao Pei ◽  
Sheng Yu ◽  
Cuan Yang Sun ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Weibull Distribution ◽  
Fatigue Reliability ◽  
Load Spectrum ◽  
Distribution Fitting ◽  
Random Load ◽  
Structural Fatigue ◽  
History Of ◽  
Drive Axle ◽  
Drive Axle Housing

Statistical analysis of load spectrum is an important part on structural fatigue life and reliability research, it is generally considered that axle’s load spectrum follows Weibull distribution. This paper tested ZL50 loader’s loading history of different working conditions , and obtained the corresponding load spectrum by rain-flow counting method, then analyzed three distributions’ (normal distribution, lognormal distribution, Weibull distribution) fitting degree of load spectrum and effect on the fatigue reliability. Results show that the highest fitting degree of distribution function should be used to fit load spectrum, which can reduce the error in structural fatigue reliability prediction.

Method of Testing and Data Processing of Random Load Spectrum of Wheel Loader Transmission

2011 ◽  
Vol 460-461 ◽  
pp. 252-257
Author(s):  
Ji Xin Wang ◽  
Ji Yong Hu ◽  
Yong Hai Yang ◽  
Wan Jun Hao ◽  
Ming Yao Yao
Keyword(s):  
Data Processing ◽  
Time History ◽  
Field Testing ◽  
Test System ◽  
Load Testing ◽  
Load Spectrum ◽  
Random Load ◽  
Heavy Load ◽  
Wheel Loader ◽  
Work Cycle

A continuous non-stationary load spectrum of wheel loader transmission was obtained from field testing by a special test system, including time-history of torque, speed, oil pressure and gears. During the data processing, each work cycle was divided into six steps: no-load forward, shoveling, heavy-load back, heavy-load forward, unloading and no-load back with considering the characteristic of gears, torque and oil pressure signals. Discretization, Butterworth filter and the singularity rejecting were adopted to analyze the load data of each step, from which the non-stationary random signals were translated into the pure stationary load signals. The time-history load testing method and data processing of random load spectrum of transmission was presented.

Analysis on Load Spectrum of Bogie Frame for High-Speed EMU

2014 ◽  
Vol 633-634 ◽  
pp. 1166-1173
Author(s):  
Yu Guang Wang ◽  
Da Fu Zhang
Keyword(s):  
Fatigue Life ◽  
Dynamic Model ◽  
High Speed ◽  
Estimation Method ◽  
Time History ◽  
Load Spectrum ◽  
Safe Operation ◽  
Bogie Frame ◽  
Key Factor ◽  
History Of

The load spectrum, on which there is not a thorough research, is the key factor of the safe operation of EMU. A dynamic model of some high-speed EMU is established and the load time history of main load on frame is obtained through simulation and analysis based on the Beijing-Tianjin route. The load spectrum for main load is calculated by rain-flow counting, the crossing contrast of load spectrum in basic and fault conditions is proceeded as well, the extent of impact of all kinds of fault conditions to bogie main load is analyzed and a brief introduction of estimation method of the frame fatigue life is put forward in this paper.

Analysis of C80B Wagon’s Load-Stress Transfer Relation

2011 ◽  
Vol 148-149 ◽  
pp. 331-335 ◽  
Author(s):  
Yu Qing Yuan ◽  
Qiang Li ◽  
Kun Ran
Keyword(s):  
Great Influence ◽  
Time History ◽  
Stress Transfer ◽  
The Body ◽  
Load Spectrum ◽  
Element Analysis ◽  
Car Body ◽  
History Of The Body ◽  
Stress Spectrum ◽  
History Of

In this paper, C80B car body is the research object to study the load-stress transfer relationship that has great influence on the car body structure. First of all, through the test data of line DaTong to Qin Huangdao, the load-time history of C80B car body’s load on center plate, load on draw gear, roll load and torsional load have been obtained, as well as the stress-time history of the body fatigue key parts have been obtained. And the load spectrum and stress spectrum have been made up. Then the finite element analysis of the car body is made. The load-stress transfer coefficient of fatigue key parts on car body could be obtained. Last the load and stress transfer relationship in detail considering the measured data has been analyzed.

Research on Structural Fatigue Damage Based on the Superimposed Load Spectrum Method

2013 ◽  
Vol 652-654 ◽  
pp. 1367-1371
Author(s):  
Xiao Ling Shi ◽  
Ji Long Xie ◽  
Fang Wei Zhao ◽  
Rong Quan Yu
Keyword(s):  
Fatigue Damage ◽  
Structural Damage ◽  
Time History ◽  
Actual Situation ◽  
Load Spectrum ◽  
Total Stress ◽  
Structural Fatigue ◽  
Spectrum Method ◽  
Load Sequence ◽  
Total Damage

We usually calculate the fatigue damage by superimposed respective injury; the paper brings up the superimposed load spectrum method considering load sequence. It superimposed on the load spectrum of each load and obtained the total damage of total stress time history. Finally, as an example, bolster’s damage is calculated by two ways. By contrast, the damage is larger by former method. The injury results based on the method of superimposed load spectrum is closer to the actual situation. Therefore, the research method presented in this paper can provide a reference for future structural damage.

Frequency Domain Fatigue Analysis for a Unbonded Flexible Riser: Damage Induced by Dynamic Bending

2020 ◽  
Author(s):  
Jiabei Yuan ◽  
Yucheng Hou ◽  
Zhimin Tan
Keyword(s):  
Tensile Stress ◽  
Frequency Domain ◽  
Fatigue Damage ◽  
Time Domain ◽  
Time History ◽  
Domain Analysis ◽  
Fatigue Analysis ◽  
Stress Spectrum ◽  
History Of ◽  
Frequency Domain Approach

Abstract The service life of flexible risers is a vital design parameter in offshore field development. The standard approach to calculate fatigue life is the nonlinear time-domain analysis. The approach uses time history of riser responses in local structure assessment to get the fatigue damage of tensile layers. Another approach is the linearized frequency-domain analysis. Instead of using time history of stress and rainflow counting technique, the approach uses stress spectrum and empirical mathematical terms to estimate the fatigue damage. The frequency domain approach is significantly faster. However, due to the whole system being linearized, the latter usually produces different results and is considered to be less accurate than the time domain approach. To address this issue, Baker Hughes previously developed an approach which uses the frequency domain technique as base solution and calibration factors from limited time domain cases. The approach is limited to tensile wires at the end fitting entrance where tension and tensile stress is directly linked. In this paper, a similar approach is proposed to be applied for tensile fatigue at all regions, whose tensile stress are induced by a combination of tension, pressure, bending and friction between layers. Since tensile stress is not directly related to any single riser response, the stress spectrum is predicted by using a transfer function. With the predicted stress spectrum, the fatigue damage of each case is calculated with Dirlik’s method and SN curves. The paper summarizes the development of the hybrid frequency domain approach. The fatigue damage of risers from several projects are acquired with both time domain and frequency domain approaches. The approach is significantly faster than traditional time domain approach and produces conservative results. Furthermore, discussions are made on options to improve the approach and reduce the conservatism in the frequency domain fatigue analysis.

scholarly journals Multiaxial high-cycle fatigue modelling for random loading

2019 ◽  
Vol 300 ◽  
pp. 12005
Author(s):  
Haoyang Wei ◽  
Jie Chen ◽  
Patricio Carrion ◽  
Anahita Imanian ◽  
Nima Shamsaei ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Normal Stress ◽  
Life Prediction ◽  
Equivalent Stress ◽  
Multiaxial Fatigue ◽  
Fatigue Life Prediction ◽  
Load Spectrum ◽  
Critical Plane ◽  
Random Loading ◽  
Random Load

In this paper, a multiaxial fatigue life prediction model is proposed under general multiaxial random loadings. First, a brief review for existing multiaxial fatigue models is given and special focus is on the LiuMahadevan critical plane concept, which can be applied to both brittle and ductile materials. Next, new model development based on the Liu-Mahadevan critical plane concept for random loading is presented. The key concept is to use two-steps to identify the critical plane: identify the maximum damage plane due to normal stress and calculate the critical plane orientation with respect to the maximum damage plane due to normal stress. Multiaxial rain-flow cycle counting method with mean stress correction is used to estimate the damage on the critical plane. Equivalent stress transformation is proposed to convert the multiaxial random load spectrum to an equivalent constant amplitude spectrum. The equivalent stress is used for fatigue life prediction. Following this, experimental design and testing is performed for Al 7075-T6 under various different random uniaxial and multiaxial spectrums. The developed model is validated with both literature and in-house testing data. Very good agreement is observed for the investigated material. Finally, conclusion and future work is given based on the proposed study.

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