Tian Ma, Chenhui Fu^*, Jiayi Yang, Jiehui Zhang, Chuyang Shang

CMC-Computers, Materials & Continua, Vol.77, No.1, pp. 1103-1122, 2023, DOI:10.32604/cmc.2023.042416

Abstract Low-light image enhancement methods have limitations in addressing issues such as color distortion, lack of vibrancy, and uneven light distribution and often require paired training data. To address these issues, we propose a two-stage unsupervised low-light image enhancement algorithm called Retinex and Exposure Fusion Network (RF-Net), which can overcome the problems of over-enhancement of the high dynamic range and under-enhancement of the low dynamic range in existing enhancement algorithms. This algorithm can better manage the challenges brought about by complex environments in real-world scenarios by training with unpaired low-light images and regular-light images. In the first stage, we design a… More >

Saima Yasmeen¹, Muhammad Usman Yaseen^1,*, Syed Sohaib Ali², Moustafa M. Nasralla³, Sohaib Bin Altaf Khattak³

CMC-Computers, Materials & Continua, Vol.76, No.3, pp. 3671-3689, 2023, DOI:10.32604/cmc.2023.041195

Abstract SAR images commonly suffer from speckle noise, posing a significant challenge in their analysis and interpretation. Existing convolutional neural network (CNN) based despeckling methods have shown great performance in removing speckle noise. However, these CNN-based methods have a few limitations. They do not decouple complex background information in a multi-resolution manner. Moreover, they have deep network structures that may result in many parameters, limiting their applicability to mobile devices. Furthermore, extracting key speckle information in the presence of complex background is also a major problem with SAR. The proposed study addresses these limitations by introducing a lightweight pyramid and attention-based… More >

Xiaoyu Zhang^1,2, Huizhong Zeng², Shaohui Zhang², Yan Zhang^3,*, Mi Xiao⁴, Liping Liu², Hao Zhou^2,*, Hongyou Chai², Liang Gao⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.1, pp. 201-220, 2024, DOI:10.32604/cmes.2023.029389

Abstract Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting from the sandwich effect. Such structures can be fabricated by metallic additive manufacturing technique, such as selective laser melting (SLM). However, the maximum dimensions of actual structures are usually in a sub-meter scale, which results in restrictions on their appliance in aerospace and other fields. In this work, a meter-scale thin-walled structure with lattice infill is designed for the fuel tank supporting component of the satellite by integrating a self-supporting lattice into the thickness optimization of the thin-wall. The… More >

Lifan Chen^1,*, Ning Guo¹, Zhongxuan Yang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09709

Abstract A multiscale approach [1] that couples the finite-element method (FEM) and the discrete-element method (DEM) is employed to model and analyse the earthquake fault rupture-soil-foundation interaction (FR-SFI) problem. In the approach, the soil constitutive responses are obtained from DEM solutions of representative volume elements (RVEs) embedded at the FEM integration points so as to effectively bypass the phenomenological hypotheses in conventional FEM simulations. The fault rupture surfaces and shear localization patterns under normal faults with or without foundation atop have been well captured by the multiscale approach and verified with available centrifuge experimental [2] and numerical results [3]. By examining… More >

Zhiqiang Yang^1,*, Yipeng Rao², Yi Sun¹, Junzhi Cui², Meizhen Xiang^3,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09513

Abstract An effective fracture model is established for the brittle materials with periodic distribution of micro-cracks using the second-order multiscale asymptotic methods. The main features of the model are: (i) the secondorder strain gradient included in the fracture criterions and (ii) the strain energy and the Griffith criterions for micro-crack extensions established by the multiscale asymptotic expansions. Finally, the accuracy of the presented model is verified by the experiment data and some typical fracture problems. These results illustrate that the second-order fracture model is effective for analyzing the brittle materials with periodic distribution of micro-cracks. More >

Zhengmao Yang^1,*, Junjie Yang², Yang Chen³, Fulei Jing⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09229

Abstract Woven ceramic matrix composites (CMCs), exhibiting excellent thermomechanical properties at high temperatures, are promising as alternative materials to the conventional nickel-based superalloys in the hot section components of aero-engines. Therefore, understanding and predicting the lifetime of CMCs is critical. Fatigue prediction of woven CMCs currently involves long-term and costly testing. A feasible alternative is to use predictive modelling based on a deep understanding of the damage mechanisms. Therefore, this study develops a multiscale analysis modelling method for predicting the fatigue life of CMC materials at high temperature by investigating the thermomechanical fatigue damage evolution. To represent the global thermomechanical properties… More >

Kaijin Wu^1,*, Yong Ni¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.3, pp. 1-2, 2023, DOI:10.32604/icces.2023.09028

Abstract Bioinspired architectural design for composites with much higher impact-resistance and fracture-resistance than that of individual constituent remains a major challenge for engineers and scientists. Inspired by the survival war between the mantis shrimps and abalones, we develop multiscale mechanical methods to design structures and control fractures in high-performance biomimetic materials. The first point is the optimization design of impact-resistant nacre-like materials [1-4]. By a combination of simulation, additive manufacturing, and drop tower testing we revealed that, at a critical interfacial strength or a critical prestress, the competition between intralayer cracks and interlayer delamination, or the synergistic effect between the prestress-enhanced… More >

Yinan Cui^1,*, Zhijie Li¹, Zhangtao Li¹, Zhanli Liu¹, Zhuo Zhuang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.010121

Abstract How the plasticity features influence the fracture behaviours of material is a critical question but remains far from well understood. To disclose this mystery, a multiscale plasticity-fracture coupled model is developed, which considers the atomistic-scale dislocation motion mechanism, the mesoscopic scales of discrete crack-dislocation interactions, and the continuum scale of crystalline plastic-fracture response. Body center cubic (bcc) material is chosen as an example to demonstrate the effectiveness of the developed model due to their wide applications and their special plasticity features, such as strong temperature dependence and non-Schmid effect. Several new insights about the fracture behaviour of bcc material are… More >

Jia Li¹, Yang Chen¹, Baobin Xie¹, Weizheng Lu¹, Qihong Fang^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.3, pp. 1-2, 2023, DOI:10.32604/icces.2023.010064

Abstract The high-profile high-entropy alloy shows outstanding mechanical properties. However, the accurate and reasonable models for describing the mechanical behavior of HEAs are still scarce due to their distinctive characteristics such as serious lattice distortion, which limit the engineering application. We have developed a new general framework combining atomic simulation, discrete dislocation dynamics and crystal plasticity finite element method, to study the deformation behaviour and strengthening mechanism of HEAs, and realized the influence of complex cross-scale factors on material deformation [1-3]. Compared with the classic crystal plasticity finite element, the bottom-up hierarchical multiscale model could couple the underlying physical mechanisms from… More >

Xiaoding Wei^1,*, Wenqing Zhu¹, Junjie Liu²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09998

Abstract Fiber-reinforced polymer composites with excellent impact energy absorption properties play a pivotal role in the safety of spacecraft, protection of military personnel and equipment, as well as high-speed transportation. Research on the impact performance of composite materials has always relied mainly on expensive experiments and large-scale simulations. In this talk, we will introduce the “dynamic shear-lag model” by extending the classical shear-lag model to the dynamic domain. The dynamic shear-lag model reveals the transfer characteristics of impact energy in the microstructure scale of composite materials, and establishes a quantitative relationship between the " composition-microstructure-performance" of composite materials under impact loading.… More >