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 >

Kyvia Pereira¹, Libardo V. Vanegas-Useche², Magd Abdel Wahab^{3, 4, *}

CMC-Computers, Materials & Continua, Vol.64, No.1, pp. 97-144, 2020, DOI:10.32604/cmc.2020.09862

Abstract Fretting fatigue is a type of failure that may affect various mechanical components, such as bolted or dovetail joints, press-fitted shafts, couplings, and ropes. Due to its importance, many researchers have carried out experimental tests and analytical and numerical modelling, so that the phenomena that govern the failure process can be understood or appropriately modelled. Consequently, the performance of systems subjected to fretting fatigue can be predicted and improved. This paper discusses different aspects related to the finite element modelling of fretting fatigue. It presents common experimental configurations and the analytical solutions for cylindrical contact. Then, it discusses aspects of… More >

Yuyang Sun¹, Peizhou Yan^{2, *}, Zhengzheng Li², Jiancheng Zou³, Don Hong⁴

CMC-Computers, Materials & Continua, Vol.63, No.3, pp. 1563-1574, 2020, DOI:10.32604/cmc.2020.09763

Abstract Real-time detection of driver fatigue status is of great significance for road traffic safety. In this paper, a proposed novel driver fatigue detection method is able to detect the driver’s fatigue status around the clock. The driver’s face images were captured by a camera with a colored lens and an infrared lens mounted above the dashboard. The landmarks of the driver’s face were labeled and the eye-area wassegmented. By calculating the aspect ratios of the eyes, the duration of eye closure, frequency of blinks and PERCLOS of both colored and infrared, fatigue can be detected. Based on the change of… More >

Meiling Zhuang^1,2,3, Changqing Miao^1,2,*, Rongfeng Chen^1,2

Structural Durability & Health Monitoring, Vol.14, No.1, pp. 51-79, 2020, DOI:10.32604/sdhm.2020.07663

Abstract Taizhou Yangtze River Bridge as a long-span suspension bridge, the finite element model (FEM) of it is established using the ANSYS Software. The beam4 element is used to simulate the main beam to establish the “spine beam” model of the Taizhou Yangtze River Bridge. The calculated low-order vibration mode frequency of the FEM is in good agreement with the completion test results. The model can simulate the overall dynamic response of the bridge. Based on the vehicle load survey, the Monte Carlo method is applied to simulate the traffic load flow. Then the overall dynamic response analysis of FEM is… 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 >

Zhongmin Xiao¹, Wengang Zhang², Yanmei Zhang^{1, *}, Mu Fan³

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 267-280, 2020, DOI:10.32604/cmc.2020.06567

Abstract Fluctuated loadings from currents, waves and sea ground motions are observed on offshore steel pipelines, and they will result in small cracks to propagate continuously and cause unexpected damage to offshore/geotechnical infrastructures. In spite of the availability of efficient techniques and high-power computers for solving crack problems, investigations on the fatigue life of offshore pipelines with 3D interacting cracks are still rarely found in open literature. In the current study, systematic numerical investigations are performed on fatigue crack growth behaviours of offshore pipelines containing coplanar and non-coplanar cracks. Extended finite element method (XFEM) is adopted to simulate the fatigue crack… More >

Dimitra Papagianni^{1, 2}, Magd Abdel Wahab^{3, 4, *}

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 79-97, 2020, DOI:10.32604/cmc.2020.07988

Abstract This paper deals with modeling of the phenomenon of fretting fatigue in heterogeneous materials using the multi-scale computational homogenization technique and finite element analysis (FEA). The heterogeneous material for the specimens consists of a single hole model (25% void/cell, 16% void/cell and 10% void/cell) and a four-hole model (25% void/cell). Using a representative volume element (RVE), we try to produce the equivalent homogenized properties and work on a homogeneous specimen for the study of fretting fatigue. Next, the fretting fatigue contact problem is performed for 3 new cases of models that consist of a homogeneous and a heterogeneous part (single… 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 >

C. Braccesi¹, F. Cianetti^1,2

Structural Durability & Health Monitoring, Vol.7, No.1&2, pp. 83-118, 2011, DOI:10.3970/sdhm.2011.007.083

Abstract In this paper the problem of the correct evaluation of the stress state of mechanical components of non linear systems in the frequency domain was analysed. This is one of the most important steps in the frequency domain evaluation of the fatigue behaviour of components submitted to random loads. A new methodology to obtain an accurate representation in frequency domain of the non-linear behaviour of the system as well as of the stress state of the components both in terms of power spectral density (PSD) function and of frequency response function (FRF) was proposed and validated. This methodology is useful… More >