Zifeng Yu¹, Xianfeng Li^1,*, Lianpeng Sun², Jinjun Zhu², Jianxin Lin³

CMC-Computers, Materials & Continua, Vol.78, No.1, pp. 435-451, 2024, DOI:10.32604/cmc.2023.046685

Abstract Urban sewer pipes are a vital infrastructure in modern cities, and their defects must be detected in time to prevent potential malfunctioning. In recent years, to relieve the manual efforts by human experts, models based on deep learning have been introduced to automatically identify potential defects. However, these models are insufficient in terms of dataset complexity, model versatility and performance. Our work addresses these issues with a multi-stage defect detection architecture using a composite backbone Swin Transformer. The model based on this architecture is trained using a more comprehensive dataset containing more classes of defects. By ablation studies on the… More >

Yanhui Zhang¹, Lianhua Ma¹, Hailiang Su^1,2,3,*, Jirong Qin², Zhining Chen², Kaibiao Deng¹

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.2, pp. 1961-1980, 2024, DOI:10.32604/cmes.2023.045570

Abstract In this paper, to present a lightweight-developed front underrun protection device (FUPD) for heavy-duty trucks, plain weave carbon fiber reinforced plastic (CFRP) is used instead of the original high-strength steel. First, the mechanical and structural properties of plain carbon fiber composite anti-collision beams are comparatively analyzed from a multi-scale perspective. For studying the design capability of carbon fiber composite materials, we investigate the effects of TC-33 carbon fiber diameter (D), fiber yarn width (W) and height (H), and fiber yarn density (N) on the front underrun protective beam of carbon fiber composite materials. Based on the investigation, a material-structure matching… More >

Qifeng Shan^1,2, Ming Mao², Yushun Li^3,*

Journal of Renewable Materials, Vol.12, No.1, pp. 149-166, 2024, DOI:10.32604/jrm.2023.029445

Abstract A theoretical analysis of upward deflection and midspan deflection of prestressed bamboo-steel composite beams is presented in this study. The deflection analysis considers the influences of interface slippage and shear deformation. Furthermore, the calculation model for flexural capacity is proposed considering the two stages of loading. The theoretical results are verified with 8 specimens considering different prestressed load levels, load schemes, and prestress schemes. The results indicate that the proposed theoretical analysis provides a feasible prediction of the deflection and bearing capacity of bamboo-steel composite beams. For deflection analysis, the method considering the slippage and shear deformation provides better accuracy.… More >

Xiaoyang Shen¹, Xiaojing Zhang^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.28, No.1, pp. 1-3, 2023, DOI:10.32604/icces.2023.010519

Abstract 1 General Introduction
Reliable structural health monitoring with high detection probability is very important [1]. Therefore, the method of finite element simulation was adopted. Based on the basic equation of material mechanics and stiffness degradation theory, to detect the damage of composite laminates, and further improves the intelligence of the detection process through the method of visual detection neural network.

2 Theoretical derivation and simulation
2.1 Equations for buckling
In the stratified damage area, each layer bears the load independently, and the bearing capacity is determined by the stiffness there: the larger the axial stiffness, the stronger the bearing capacity… More >

Zihao Yang¹, Shaoqi Zheng¹, Fei Han^2,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09250

Abstract This paper proposes a peridynamics-based statistical multiscale (PSM) framework to simulate the macroscopic structure fracture with high efficiency. The heterogeneities of composites, including the shape, spatial distribution and volume fraction of particles, are characterized within the representative volume elements (RVEs), and their impact on structure failure are extracted as two types of peridynamic parameters, namely, statistical critical stretch and equivalent micromodulus. At the microscale level, a bondbased peridynamic (BPD) model with energy-based micromodulus correction technique is introduced to simulate the fracture in RVEs, and then the computational model of statistical critical stretch is established through micromechanical analysis. Moreover, based on… More >

Yongtong Zheng^1,* , Yijun Liu¹, Xiaowei Gao^1,2,3

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.09774

Abstract Recently, a series of isoparametric boundary elements have been constructed to simulate the shape of holes, tubes, disks, rings and spheres based on the Lagrange interpolation formulation and the closure condition at two ends of an arc. These elements can simulate the models which contain the shapes mentioned above with less nodes and less elements than the conventional boundary elements. However, the basis of those elements, i.e., hole elements, have the poor accuracy when the number of nodes is less than 6. To improve these elements, two kinds of improvements are proposed in this study. The first one let more… More >

Yangao Hu^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.09773

Abstract This paper investigates the effects of graphene oxide (GO), notch depth, rebar, and load on the resistivity of cement paste and mortar. The electrical conductivity of GO/cement composite reaches its maximum value when the GO content is 0.03%, which is approximately 50% higher compared to the composite without GO. The resistivity of GO/cement composite shows significant changes with increasing load from 0 to 40 kN. The gauge factor for compressive loading varies from about 26 to 73 for different GO contents. Moreover, the resistivity variation with the notch depth in GO/cement is found to be much greater than that in… More >

Jiamin Xiang¹, Ying Zhang¹, Xiaohua Cao^1,*, Zhigang Zhou²

CMC-Computers, Materials & Continua, Vol.77, No.3, pp. 3443-3466, 2023, DOI:10.32604/cmc.2023.045120

Abstract This paper presents an improved hybrid algorithm and a multi-objective model to tackle the scheduling problem of multiple Automated Guided Vehicles (AGVs) under the composite operation mode. The multi-objective model aims to minimize the maximum completion time, the total distance covered by AGVs, and the distance traveled while empty-loaded. The improved hybrid algorithm combines the improved genetic algorithm (GA) and the simulated annealing algorithm (SA) to strengthen the local search ability of the algorithm and improve the stability of the calculation results. Based on the characteristics of the composite operation mode, the authors introduce the combined coding and parallel decoding… More >

Rabar H. Faraj^1,*, Hemn Unis Ahmed^2,3, Hardi Saadullah Fathullah⁴, Alan Saeed Abdulrahman², Farid Abed⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2925-2954, 2024, DOI:10.32604/cmes.2023.029392

Abstract Plain concrete is strong in compression but brittle in tension, having a low tensile strain capacity that can significantly degrade the long-term performance of concrete structures, even when steel reinforcing is present. In order to address these challenges, short polymer fibers are randomly dispersed in a cement-based matrix to form a highly ductile engineered cementitious composite (ECC). This material exhibits high ductility under tensile forces, with its tensile strain being several hundred times greater than conventional concrete. Since concrete is inherently weak in tension, the tensile strain capacity (TSC) has become one of the most extensively researched properties. As a… More >

Bradley Doleman^a , Messiha Saad^a,*

Frontiers in Heat and Mass Transfer, Vol.4, No.2, pp. 1-8, 2013, DOI:10.5098/hmt.v4.2.3006

Abstract Thermal diffusivity, specific heat, and thermal conductivity are important thermophysical properties of composite materials. These properties play a significant role in the engineering design process of space systems, aerospace vehicles, transportation, energy storage devices, and power generation including fuel cells. This paper examines these thermophysical properties of the AS4/3501-6 composite using the xenon flash method to measure the thermal diffusivity in accordance with ASTM E1461 and differential scanning calorimetry to measure the specific heat in accordance with ASTM E1269. The thermal conductivity was then calculated using a proportional relationship between the density, specific heat, and thermal diffusivity. More >