Ying Wang^1,*, Zheng Yan¹, Zhen Wang²

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.2, pp. 549-574, 2021, DOI:10.32604/cmes.2021.014727

Abstract Due to the complex structure and dense weld of the orthotropic steel bridge deck (OSBD), fatigue cracks are prone to occur in the typical welding details. Welding residual stress (WRS) will cause a plastic zone at the crack tip. In this paper, an elastoplastic constitutive model based on the Chaboche kinematic hardening model was introduced, and the extended finite element method (XFEM) was used to study the influence of material elastoplasticity and crack tip plastic zone on the law of fatigue crack propagation. By judging the stress state of the residual stress field at the crack tip and selecting different… More >

Fang Shi^1,*, Daobing Wang², Xiaogang Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.2, pp. 575-598, 2021, DOI:10.32604/cmes.2021.015384

Abstract Field data suggests that carbonate reservoirs contain abundant natural fractures and cavities. The propagation mechanisms of hydraulic fractures in fracture-cavity reservoirs are different from conventional reservoirs on account of the stress concentration surrounding cavities. In this paper, we develop a fully coupled numerical model using the extended finite element method (XFEM) to investigate the behaviors and propagation mechanisms of hydraulic fractures in fracture-cavity reservoirs. Simulation results show that a higher lateral stress coefficient can enhance the influence of the natural cavity, causing a more curved fracture path. However, lower confining stress or smaller in-situ stress difference can reduce this influence,… More >

Qiong Liu, Jianzhuang Xiao^*, Amardeep Singh

Journal of Renewable Materials, Vol.9, No.7, pp. 1309-1327, 2021, DOI:10.32604/jrm.2021.015326

Abstract The failure characteristics of recycled concrete containing brick aggregates are still indistinct, especially how the angular aggregates effect the crack propagation. Based on the concept of modeled concrete, the development of cracks in concrete containing the natural aggregate and brick aggregate under a compression loading was studied. The strain distribution was analyzed with the Digital Image Correlation (DIC). The modeled aggregates include circular and squared ones, and the squared modeled aggregates were placed in different orientations, including 0°, 22.5° and 45°. The results show that when the aggregate is placed at 45°, the upper and lower vertices of the aggregate… More >

Daobing Wang¹, Fang Shi^2,*, Hao Qin^1,*, Dongliang Sun¹, Bo Yu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.3, pp. 891-914, 2021, DOI:10.32604/cmes.2021.014206

Abstract In this study, we use the extended finite element method (XFEM) with a consideration of junction enrichment functions to investigate the mechanics of hydraulic fractures related to naturally cemented fractures. In the proposed numerical model, the lubrication equation is adopted to describe the fluid flow within fractures. The fluid-solid coupling systems of the hydraulic fracturing problem are solved using the Newton-Raphson method. The energy release rate criterion is used to determine the cross/arrest behavior between a hydraulic fracture (HF) and a cemented natural fracture (NF). The failure patterns and mechanisms of crack propagation at the intersection of natural fractures are… More >

Xibo Qi¹, Yijie Huang^2,3,*, Xiaowei Li¹, Zhenhua Hu¹, Jingwei Ying³, Dayong Li¹

Journal of Renewable Materials, Vol.8, No.8, pp. 915-937, 2020, DOI:10.32604/jrm.2020.010991

Abstract The mechanical properties of modified sea water sea sand coral concrete (SWSSCC) under axial compression were experimentally studied. Two different parameters were considered in this test: types of cement and fiber. An experimental campaign was developed involving uniaxial compression tests and the use of digital image correlation (DIC) method to analyze the strain distribution and crack propagation of specimen. Test results indicated that the compressive strength and elastic modulus of SWSSCC were improved by adding stainless steel fibers (SSF), while polypropylene fibers (PF) enhanced the SWSSCC peak deformation. It was found that the elastic modulus and strength of SWSSCC using… 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 >

Zhanqi Cheng¹, Dongdong Jin¹, Chengfang Yuan¹, Le Li^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 445-464, 2019, DOI:10.32604/cmes.2019.06374

Abstract In the research, the dynamic fracture failure problem of functionally graded materials (FGMs) containing two pre-cracks was analyzed using a bond-based Peridynamic (PD) method numerical model. The two convergence of decreasing the area of PD horizon (δ-convergence) and uniform mesh refinement (m-convergence) were studied. The effects of both crack position and distance between two cracks on crack propagation pattern in FGMs plate under tensile loads are studied. Furthermore, the effects of different gradient patterns on the dynamic propagation of cracks in FGMs are also investigated. The simulate results suggest that the cracks positions and the distance between them can significantly… More >

G. Dhondt¹, D. Bremberg²

Structural Durability & Health Monitoring, Vol.6, No.3&4, pp. 305-328, 2010, DOI:10.3970/sdhm.2010.006.305

Abstract In a previous article the K-distritubion along the crack front of several mixed-mode specimens was investigated [Dhondt, Chergui, and Buchholz (2001)]. Both the modified virtual crack closure integral method and the quarter point element stress field method yielded results close to the available reference solutions in the literature [Murakami (1987)]. The present paper extends these results in two aspects. First, the meshing procedure used to obtain a focused mesh at the crack front is modified in order to deal with highly curved cracks. Secondly, the K-distribution along the initial crack is used to perform a crack propagation calculation. The form… More >

S.M.O. Tavares¹, S.M. Häusler², P.M. Baiz³, P.M.S.T. de Castro¹, P. Horst² , M.H. Aliabadi³

Structural Durability & Health Monitoring, Vol.7, No.3, pp. 191-210, 2011, DOI:10.3970/sdhm.2011.007.191

Abstract This article is the second part of a two parts paper which presents, compares and discusses the different crack growth simulation models which were introduced for fatigue crack growth assessment during the DaToN project. In the first part, different simulation approaches were applied to determine a calibration of the stress intensity factors as a function of the crack length for a two stiffeners panel with a central crack. Due to the residual stress field promoted by the different manufacturing processes, its influence was included in the numerical models to determine the stress intensity factors. In this second part, the stress… More >

S.M. Häusler¹, P.M. Baiz², S.M.O. Tavares³, A. Brot⁴, P. Horst¹, M.H. Aliabadi², P.M.S.T. de Castro³, Y. Peleg-Wolfin⁴

Structural Durability & Health Monitoring, Vol.7, No.3, pp. 163-190, 2011, DOI:10.3970/sdhm.2011.007.163

Abstract This article represents the first part of a two-part article which presents, compares and discusses the different crack growth simulation models which were introduced for fatigue crack growth assessment during the DaToN project. The project was funded by the EC within the 6th framework program and was specifically devoted to investigate innovative manufacturing techniques for metallic structures with special focus on the effects of residual stresses on the fatigue crack growth and residual strength behaviour. Within this first part the different simulation approaches, including the residual stress modelling approaches will be introduced and stress intensity factor results will be presented… More >