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

CMES-Computer Modeling in Engineering & Sciences, Vol., , 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 >

Xiaorui Zhang^1,2,*, Jiali Duan¹, Wei Sun², Tong Xu¹, Sunil Kumar Jha³

CMES-Computer Modeling in Engineering & Sciences, Vol., , DOI:10.32604/cmes.2021.012034

Abstract The cutting simulation of soft tissue is important in virtual surgery. It includes three major challenges in computation: Soft tissue simulation, collision detection, and handling, as well as soft tissue models. In order to address the earlier challenges, we propose a virtual cutting system based on the mass-spring model. In this system, MSM is utilized to simulate the soft tissue model. Residual stress is introduced to the model for simulating the shrinking effect of soft tissue in cutting. Second, a cylinder-based collision detection method is used to supervise the collision between surgical tools and soft tissue. Third, we simulate the… More >

Chunlei Zhang^1,2,3,*, Y. P. Chugh², Ruimin Feng⁴, Yong Zhang⁵, Wei Shen¹, Jingke Wu¹, Yushun Yang¹

CMES-Computer Modeling in Engineering & Sciences, Vol., , DOI:10.32604/cmes.2021.014665

Abstract Extraction of a protective coal seam (PVCS)-below or above a coal seam to be mined with the potential of coal and gas outburst risk-plays an important role not only in decreasing the stress field in the surrounding rock mass but also in increasing the gas desorption capacity and gas flow permeability in the protected coal seam (PTCS). The PVCS is mined to guarantee the safe mining of the PTCS. This study has numerically evaluated the stress redistribution effects using FLAC3D model for a longwall face in Shanxi Province. The effects of mining depth, mining height and inter-burden rock mass properties… More >

Mohammed Lafi^1,*, Bilal Hawashin², Shadi AlZu’ bi³

CMES-Computer Modeling in Engineering & Sciences, Vol., , DOI:10.32604/cmes.2021.013026

Abstract Most software systems have different stakeholders with a variety of concerns. The process of collecting requirements from a large number of stakeholders is vital but challenging. We propose an efficient, automatic approach to collecting requirements from different stakeholders’ responses to a specific question. We use natural language processing techniques to get the stakeholder response that represents most other stakeholders’ responses. This study improves existing practices in three ways: Firstly, it reduces the human effort needed to collect the requirements; secondly, it reduces the time required to carry out this task with a large number of stakeholders; thirdly, it underlines the… More >

Caili Li¹, Dalin Tang^2,*,3, Jing Yao^4,*, Christopher Baird⁵, Haoliang Sun⁶, Chanjuan Gong⁷, Luyao Ma⁶, Yanjuan Zhang⁴, Liang Wang², Han Yu², Chun Yang⁸, Yongfeng Shao⁶

CMES-Computer Modeling in Engineering & Sciences, Vol., , DOI:10.32604/cmes.2021.014580

Abstract Aortic valve replacement (AVR) remains a major treatment option for patients with severe aortic valve disease. Clinical outcome of AVR is strongly dependent on implanted prosthetic valve size. Fluid-structure interaction (FSI) aortic root models were constructed to investigate the effect of valve size on hemodynamics of the implanted bioprosthetic valve and optimize the outcome of AVR surgery. FSI models with 4 sizes of bioprosthetic valves (19 (No. 19), 21 (No. 21), 23 (No. 23) and 25 mm (No. 25)) were constructed. Left ventricle outflow track flow data from one patient was collected and used as model flow conditions. Anisotropic Mooney–Rivlin… More >

Tantan Zhu¹, Da Huang^2,3,*, Jianxun Chen¹, Yanbin Luo¹, Longfei Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol., , DOI:10.32604/cmes.2021.014808

Abstract Excavation and earth surface processes (e.g., river incision) always induce the unloading of stress, which can cause the failure of rocks. To study the shear mechanical behavior of a rock sample under unloading normal stress conditions, a new stress path for direct shear tests was proposed to model the unloading of stress caused by excavation and other processes. The effects of the initial stresses (i.e., the normal stress and shear stress before unloading) on the shear behavior and energy conversion were investigated using laboratory tests and numerical simulations. The shear strength of a rock under constant stress or under unloading… More >

Mustafa Turkyilmazoglu^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol., , DOI:10.32604/cmes.2021.012595

Abstract The present paper is devoted to the convergence control and accelerating the traditional Decomposition Method of Adomian (ADM). By means of perturbing the initial or early terms of the Adomian iterates by adding a parameterized term, containing an embedded parameter, new modified ADM is constructed. The optimal value of this parameter is later determined via squared residual minimizing the error. The failure of the classical ADM is also prevented by a suitable value of the embedded parameter, particularly beneficial for the Duan–Rach modification of the ADM incorporating all the boundaries into the formulation. With the presented squared residual error analysis,… More >

Muhammad Riaz¹, Masooma Raza Hashmi¹, Dragan Pamucar², Yuming Chu^3,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol., , DOI:10.32604/cmes.2021.013699

Abstract The existing concepts of picture fuzzy sets (PFS), spherical fuzzy sets (SFSs), T-spherical fuzzy sets (T-SFSs) and neutrosophic sets (NSs) have numerous applications in decision-making problems, but they have various strict limitations for their satisfaction, dissatisfaction, abstain or refusal grades. To relax these strict constraints, we introduce the concept of spherical linear Diophantine fuzzy sets (SLDFSs) with the inclusion of reference or control parameters. A SLDFS with parameterizations process is very helpful for modeling uncertainties in the multi-criteria decision making (MCDM) process. SLDFSs can classify a physical system with the help of reference parameters. We discuss various real-life applications of… More >

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

CMES-Computer Modeling in Engineering & Sciences, Vol., , 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 >

Sunil Kr. Jha^1,*, Ivan Uzunov², Xiaorui Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol., , DOI:10.32604/cmes.2021.011821

Abstract Ohrid trout (Salamo letnica) is an endemic species of fish found in Lake Ohrid in the Former Yugoslav Republic of Macedonia (FYROM). The growth of Ohrid trout was examined in a controlled environment for a certain period, thereafter released into the lake to grow their natural population. The external features of the fish were measured regularly during the cultivation period in the laboratory to monitor their growth. The data mining methods-based computational model can be used for fast, accurate, reliable, automatic, and improved growth monitoring procedures and classification of Ohrid trout. With this motivation, a combined approach of principal component… More >