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… 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… 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… 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… 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 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… 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 More >

Ying Wang*, Zhen Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.4, pp. 176-176, 2019, DOI:10.32604/icces.2019.05665

Abstract Due to stress concentration as well as welding residual stress, fracture due to vehicle fatigue loads is easy to occur in the weld and its adjacent position of long-span bridge, especially at the toe of weld between the U-rib and orthotropic steel bridge deck. In order to investigate the fatigue crack propagation mechanism of the toe of weld in long-span bridge, a multi-scale finite element model including the whole bridge, local components, the welding details and cracks was established firstly. And then, based on birth and death element technology, the welding heat and structural coupling… More >

Kei Saito^1,*, Tei Hirashima¹, Ninshu Ma², Hidekazu Murakawa²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.4, pp. 174-174, 2019, DOI:10.32604/icces.2019.05406

Abstract Characteristic tensor is a tensor which is derived from the characteristic stress field near to a crack tip and is strongly related to fracture mechanics parameters in principle. Each component of characteristic tensor consists of an invariant quantity which defines intensity of stress singularity, corresponding to the stress component. Since it contains the information about not only intensity but also direction of the singularity, characteristic tensor can be a possible candidate which evaluates characteristics of cracking and its propagation direction under various complex loading conditions we have to assume for the practical analysis. Though parameters… More >

Yabin Yang, Guangyu Shi^*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 35-35, 2019, DOI:10.32604/icces.2019.05623

Abstract The efficient and high performance orthotropic steel decks have been widely used in long span bridges over the world. The initial defects at welded joints of orthotropic steel bridge decks will undergo fatigue failure under the action of live load of moving vehicles on the bridge decks. And the fatigue cracks at the rib-to-deck welded joints are the most dangerous cracks for the orthotropic steel bridge decks. Therefore, the fatigue life evaluation of the rib-to-deck welded joints is very important for the safety of orthotropic steel bridge decks. This paper presents a crack propagation-based model… More >