Mingjian Li, Ping Yang^*, Pengyang Zhao

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 2019-2034, 2024, DOI:10.32604/cmes.2024.048334

Abstract The experimental results in previous studies have indicated that during the ductile fracture of pure metals, vacancies aggregate and form voids at grain boundaries. However, the physical mechanism underlying this phenomenon remains not fully understood. This study derives the equilibrium distribution of vacancies analytically by following thermodynamics and the micromechanics of crystal defects. This derivation suggests that vacancies cluster in regions under hydrostatic compression to minimize the elastic strain energy. Subsequently, a finite element model is developed for examining more general scenarios of interaction between vacancies and grain boundaries. This model is first verified and More >

Xingliang Deng¹, Peng Cao^2,*, Yintao Zhang¹, Yuhui Zhou³, Xiao Luo¹, Liang Wang³

Energy Engineering, Vol.121, No.5, pp. 1195-1207, 2024, DOI:10.32604/ee.2023.045870

Abstract The fractured-vuggy carbonate oil resources in the western basin of China are extremely rich. The connectivity of carbonate reservoirs is complex, and there is still a lack of clear understanding of the development and topological structure of the pore space in fractured-vuggy reservoirs. Thus, effective prediction of fractured-vuggy reservoirs is difficult. In view of this, this work employs adaptive point cloud technology to reproduce the shape and capture the characteristics of a fractured-vuggy reservoir. To identify the complex connectivity among pores, fractures, and vugs, a simplified one-dimensional connectivity model is established by using the meshless More >

Yuhang Wang^1,*, Zhiqin He¹, Qinmu Wu¹, Tingsheng Lu², Yu Tang¹, Maoyun Zhu¹

CMC-Computers, Materials & Continua, Vol.79, No.1, pp. 1377-1398, 2024, DOI:10.32604/cmc.2024.047379

Abstract This paper addresses the common orthopedic trauma of spinal vertebral fractures and aims to enhance doctors’ diagnostic efficiency. Therefore, a deep-learning-based automated diagnostic system with multi-label segmentation is proposed to recognize the condition of vertebral fractures. The whole spine Computed Tomography (CT) image is segmented into the fracture, normal, and background using U-Net, and the fracture degree of each vertebra is evaluated (Genant semi-qualitative evaluation). The main work of this paper includes: First, based on the spatial configuration network (SCN) structure, U-Net is used instead of the SCN feature extraction network. The attention mechanism and… More >

Fayez Alfayez^*

CMC-Computers, Materials & Continua, Vol.79, No.1, pp. 1539-1560, 2024, DOI:10.32604/cmc.2024.046443

Abstract This paper emphasizes a faster digital processing time while presenting an accurate method for identifying spine fractures in X-ray pictures. The study focuses on efficiency by utilizing many methods that include picture segmentation, feature reduction, and image classification. Two important elements are investigated to reduce the classification time: Using feature reduction software and leveraging the capabilities of sophisticated digital processing hardware. The researchers use different algorithms for picture enhancement, including the Wiener and Kalman filters, and they look into two background correction techniques. The article presents a technique for extracting textural features and evaluates three… More >

Chengbao Hu^1,2,3, Shilin Gong^4,*, Bin Chen^1,2,3, Zhongling Zong⁴, Xingwang Bao⁵, Xiaojian Ru⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 997-1015, 2024, DOI:10.32604/cmes.2024.048640

Abstract Strain localization frequently occurs in cohesive materials with friction (e.g., composites, soils, rocks) and is widely recognized as a fundamental cause of progressive structural failure. Nonetheless, achieving high-fidelity simulation for this issue, particularly concerning strong discontinuities and tension-compression-shear behaviors within localized zones, remains significantly constrained. In response, this study introduces an integrated algorithm within the finite element framework, merging a coupled cohesive zone model (CZM) with the nonlinear augmented finite element method (N-AFEM). The coupled CZM comprehensively describes tension-compression and compression-shear failure behaviors in cohesive, frictional materials, while the N-AFEM allows nonlinear coupled intra-element discontinuities More >

Gang Niu^1,2, Zhaoyang Jin², Wei Zhang^3,*, Yiqun Huang³

Structural Durability & Health Monitoring, Vol.18, No.2, pp. 161-179, 2024, DOI:10.32604/sdhm.2023.044580

Abstract Amid urbanization and the continuous expansion of transportation networks, the necessity for tunnel construction and maintenance has become paramount. Addressing this need requires the investigation of efficient, economical, and robust tunnel reinforcement techniques. This paper explores fiber reinforced polymer (FRP) and steel fiber reinforced concrete (SFRC) technologies, which have emerged as viable solutions for enhancing tunnel structures. FRP is celebrated for its lightweight and high-strength attributes, effectively augmenting load-bearing capacity and seismic resistance, while SFRC’s notable crack resistance and longevity potentially enhance the performance of tunnel segments. Nonetheless, current research predominantly focuses on experimental analysis,… More > Graphic Abstract

Xue Liang^1,2, Linjuan Wang^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 2807-2834, 2024, DOI:10.32604/cmes.2024.046770

Abstract The peridynamics (PD), as a promising nonlocal continuum mechanics theory, shines in solving discontinuous problems. Up to now, various numerical methods, such as the peridynamic mesh-free particle method (PD-MPM), peridynamic finite element method (PD-FEM), and peridynamic boundary element method (PD-BEM), have been proposed. PD-BEM, in particular, outperforms other methods by eliminating spurious boundary softening, efficiently handling infinite problems, and ensuring high computational accuracy. However, the existing PD-BEM is constructed exclusively for bond-based peridynamics (BBPD) with fixed Poisson’s ratio, limiting its applicability to crack propagation problems and scenarios involving infinite or semi-infinite problems. In this paper,… More >

Shijun Zhao¹, Qing Zhang², Yusong Miao¹, Weizhao Zhang³, Xinbo Zhao¹, Wei Xu^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 3167-3187, 2024, DOI:10.32604/cmes.2023.045015

Abstract The surrounding rock of roadways exhibits intricate characteristics of discontinuity and heterogeneity. To address these complexities, this study employs non-local Peridynamics (PD) theory and reconstructs the kernel function to represent accurately the spatial decline of long-range force. Additionally, modifications to the traditional bond-based PD model are made. By considering the micro-structure of coal-rock materials within a uniform discrete model, heterogeneity characterized by bond random pre-breaking is introduced. This approach facilitates the proposal of a novel model capable of handling the random distribution characteristics of material heterogeneity, rendering the PD model suitable for analyzing the deformation… More >

Diguang Gong¹, Junbin Chen¹, Cheng Cheng², Yuanyuan Kou^2,*

Energy Engineering, Vol.121, No.2, pp. 425-437, 2024, DOI:10.32604/ee.2023.030196

Abstract Horizontal well-stimulation is the key to unconventional resource exploration and development. The development mode of the well plant helps increase the stimulated reservoir volume. Nevertheless, fracture interference between wells reduces the fracturing effect. Here, a 2D hydro-mechanical coupling model describing hydraulic fracture (HF) propagation is established with the extended finite element method, and the effects of several factors on HF propagation during multiple wells fracturing are analyzed. The results show that with an increase in elastic modulus, horizontal principal stress difference and injection fluid displacement, the total fracture area and the reservoir stimulation efficiency are More >

Lifeng Liu¹, Menghe Shi², Jianhui Wang³, Wendong Wang^2,*, Yuliang Su², Xinyu Zhuang²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.3, pp. 595-607, 2024, DOI:10.32604/fdmp.2023.041962

Abstract Ultra-low permeability reservoirs are characterized by small pore throats and poor physical properties, which are at the root of well-known problems related to injection and production. In this study, a gas injection flooding approach is analyzed in the framework of numerical simulations. In particular, the sequence and timing of fracture channeling and the related impact on production are considered for horizontal wells with different fracture morphologies. Useful data and information are provided about the regulation of gas channeling and possible strategies to delay gas channeling and optimize the gas injection volume and fracture parameters. It More >