Hui Wang^1,2, Shiqin He^1,*, Xiaoqiang Yin³, Zeyang Cao¹

Structural Durability & Health Monitoring, Vol.14, No.2, pp. 95-108, 2020, DOI:10.32604/sdhm.2020.06595

Abstract In marine environments, reinforced concrete bridge structures are subjected to cyclic loads and chloride ingress, which results in corrosion of the reinforcing bars, early deterioration, durability loss, and a considerable reduction in the fatigue strength. Owing to the complexity of the problem and the difficulty of testing, there are few studies on the fatigue performance of concrete structures under the combined action of corrosion environment and cyclic load. Therefore, a coupling test device for corrosion and cyclic load is designed and fatigue tests of reinforced concrete beams in air environments and chlorine salt corrosive environments are carried out. The fatigue… More >

Qing Dong^{1, *}, Bin He¹, Gening Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.2, pp. 525-553, 2020, DOI: 10.32604/cmes.2020.08498

Abstract To compensate for the shortcomings of quasi-static law in anti-fatigue analysis of foundry crane metal structures, the fatigue life evaluation method of foundry crane metal structure considering load dynamic response and crack closure effect is proposed. In line with the theory of mechanical vibration, a dynamic model of crane structure during the working cycle is constructed, and dynamic coefficients under diverse actions are analysed. Calculation models of the internal force dynamic change process of dangerous cross-sections and a simulation model of first principal stress-time history are established by using the steel structure design criteria, which is utilised to extract the… More >

Xiaohua Zhu^1,*, Li Zeng¹, Bo Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 631-660, 2019, DOI:10.32604/cmes.2019.06755

Abstract The complicated geological conditions will bring great challenges to the drillstring of horizontal wells for the reason that the increase of the well depth in SichuanChongqing region. Since drillstring failure and friction during drilling are generally caused by drillstring vibration, great importance must be attached to computer simulation methods for the prediction of drillstring vibration. A finite element model considering axial, lateral and torsional vibration is established. In order to verify the established numerical model, an indoor experimental device based on the similarity principle was established. The vibration characteristics of three shale gas horizontal wells drillstrings are described. The reasons… More >

Ramamurty Raju P.¹, Rajesh S.¹, Satyanarayana B.², Ramji K.³

Structural Durability & Health Monitoring, Vol.7, No.1&2, pp. 139-152, 2011, DOI:10.3970/sdhm.2011.007.139

Abstract This paper presents the details of method of sample size determination to estimate the characteristic fatigue life of aluminum alloy, A356.2-T6. The characteristic fatigue life of the alloy has been estimated by assuming log normal distribution model. A step wise procedure is outlined to determine the number of specimens required at predetermined stress amplitude to estimate the fatigue life with an acceptable error at 50% probability and various confidence levels, 90%, 95% and 99%. Maximum percentage of errors has also been calculated for the above probability and confidence levels. Details of generation of S-N curve for aluminum alloy A356.2-T6 using… More >

S.Mohanty¹, A. Chattopadhyay², J. Wei³, P. Peralta⁴

Structural Durability & Health Monitoring, Vol.5, No.1, pp. 33-56, 2009, DOI:10.3970/sdhm.2009.005.033

Abstract The current state of the art in the area of real time structural health monitoring techniques offers adaptive damage state prediction and residual useful life assessment. The present paper discusses the use of an integrated prognosis model, which combines an on-line state estimation model with an off-line predictive model to adaptively estimate the residual useful life of an Al-6061 cruciform specimen under biaxial loading. The overall fatigue process is assumed to be a slow time scale process compared to the time scale at which, the sensor signals were acquired for on-line state estimation. The on-line state estimation model was based… More >

S. Abdullah¹

Structural Durability & Health Monitoring, Vol.4, No.4, pp. 181-198, 2008, DOI:10.3970/sdhm.2008.004.181

Abstract This paper describes a technique to identify the important features in fatigue road spectrum loading, for which these features cause the majority of the total damage. Fatigue damaging events, called bump segments, are extracted from the spectrum loading using a wavelet-based algorithm, called Wavelet Bump Extraction (WBE). This algorithm is also used to produce a shortened mission signal that retains most of the fatigue damage whilst preserving the cycle sequences. The bump identification process has been evaluated by analysing two road spectrum loadings having a variable amplitude pattern. These data sets were obtained from the strain measurement on the lower… More >

P. Ramamurty Raju¹, B. Satyanarayana², K. Ramji³

Structural Durability & Health Monitoring, Vol.4, No.3, pp. 161-172, 2008, DOI:10.3970/sdhm.2008.004.161

Abstract This paper presents the details of method of sample size determination to estimate the characteristic fatigue life of aluminum alloy. The characteristic fatigue life of Aluminum alloy A356.2-T6 has been estimated by assuming a two parameter Weibull distribution model. A stepwise procedure is outlined to determine the number of specimens required at a predetermined stress amplitude to estimate the fatigue life within an acceptable error at a given probability and confidence level. The percentage of error is calculated at various probabilities and confidence levels (C.L). The probabilities considered are 50%, 90% and 95% whereas C.Ls considered are 90%, 95% and… More >

M. M. Rahman¹, A. K. Ariffin², S. Abdullah², A. B. Rosli¹

Structural Durability & Health Monitoring, Vol.3, No.4, pp. 197-210, 2007, DOI:10.3970/sdhm.2007.003.197

Abstract Low weight and long lifetime are necessary requirements for automobiles to significantly reduce CO₂ emission and environmental burdens in their use. Aluminum alloys are one of the most promising materials selections for automobiles parts and electrical components to reduce their weight and to increase their specific strength. This paper presents the role of nitriding on the fatigue life of the vibrating cylinder block for a new two-stroke free piston engine using variable amplitude loading conditions. The finite element modeling and analysis have been performed utilising a computer aided design and a finite element analysis codes respectively. In addition, the fatigue… More >

M. M. Rahman¹, A. K. Ariffin¹, S. Abdullah¹, N. Jamaludin¹

Structural Durability & Health Monitoring, Vol.3, No.1, pp. 1-14, 2007, DOI:10.3970/sdhm.2007.003.001

Abstract A modern computational approach based on finite element analysis for durability assessment in a two-stroke free piston linear engine component using the variable amplitude loadings is presented. This paper describes the finite element analysis techniques to predict the fatigue life and identify the critical locations of the component. The effect of mean stress on the fatigue life is also investigated. The finite element modeling and analysis has been performed using a computer-aided design and a finite element analysis software package, and the fatigue life prediction was carried out using finite element based fatigue life prediction codes. The fatigue crack initiation… More >

M. M. Rahman¹, A.K. Ariffin, N. Jamaludin, C. H. C. Haron

Structural Durability & Health Monitoring, Vol.2, No.2, pp. 69-82, 2006, DOI:10.3970/sdhm.2006.002.069

Abstract This paper describes finite element based vibration fatigue analysis techniques to predict fatigue life using the narrow band frequency response approach. The life prediction results are useful for improving the component design at a very early development stage. The approach is found to be suitable for periodic loading but requires very large time records to accurately describe random loading processes. The focus of this paper is to investigate the effects of surface treatments on the fatigue life of the components of free piston linear engine. The finite element modeling and frequency response analysis have been performed using a computer-aided design… More >