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Acta Mechanica Sinica 2023年第9期39卷 100-113页

作者：张宁郑宏杨亮王熠琛武文安 School of Civil Engineering Qinghai University Qinghai 810016China Key Laboratory of Urban Security and Disasier Engineering Ministry of EducationBeijing University of TechnologyBeijing100124China Agiletech Engineering Consulants Co. LidBejing 100037China National Engineering Lab for Green and Safe Construction Technology in Urban Rail Transit Beijing 100037China

凭借切割运算,数值流形方法(NMM)可通过最简单的规则网格处理任意形状的问题域然而,这通常会生成很多低阶的、形状不规则的单元。因此NMM不但需要大量积分点,而且在几乎不可压缩和弯曲变形占优时常常存在自锁现象.为解决上述问题,本研... 详细信息

凭借切割运算,数值流形方法(NMM)可通过最简单的规则网格处理任意形状的问题域然而,这通常会生成很多低阶的、形状不规则的单元。因此NMM不但需要大量积分点,而且在几乎不可压缩和弯曲变形占优时常常存在自锁现象.为解决上述问题,本研究将建立一个数值稳定的单点积分策略.通过单元的矩,该策略将单元虚功分解为零阶主项和高阶稳定项,进一步通过修正高阶稳定项中的球应变部分和剪切应变部分,达到克服体积自锁和剪切自锁的目的,并用始终非零的稳定项克服沙漏变形.除了积分点更少外,新方法不存在体积自锁、剪切自锁和沙漏模式,因而也具有更高精度.文中数值算例验证了新规则的鲁棒性和精度提升.

关键词：自锁现象数值流形方法规则网格沙漏模式剪切应变精度提升积分点

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Simulation Experimental Study on Evolution Law of Cumulative Damage in Coal under Shocks by Multiple High Pressure Air Blasting

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ACS Omega 2025年第25期10卷 26806-26819页

作者： Yan, Shaoyang Gao, Fuqiang Sun, Bo Du, Zhigang Liu, Qi Ji, Nan Ye, Hongyu School of Intelligent Construction and Civil Engineering Luoyang Institute of Science and Technology Luoyang 471023 China Henan Key Laboratory of Green Building Materials Manufacturing and Intelligent Equipment Luoyang 471023 China School of Civil Engineering Henan Polytechnic University Jiaozuo 454000 China School of Civil Engineering Xinyu University Xinyu 338000 China

High pressure air blasting (HPAB) is a new type of waterless physical expansion method for enhancing coalbed methane extraction from low-permeability coal reservoirs. In order to explore the influence of shocks by multiple HPAB on the cumulative damage evolution of coal, shocks by multiple HPAB experiments were conducted using simulated coal samples and a self-developed HPAB device. During the experimental testing process, The wave velocity of coal samples under shocks by multiple HPAB was tested using an ultrasonic tester, and the time-domain signal of the ultrasonic wave was converted into a frequency-domain signal using Fourier transform theory. the evolution of acoustic waves and damage morphological characteristics of coal with increasing HPAB times was analyzed. Additionally,The evolution process of the three-dimensional pore and fracture structure of coal samples under Shocks by multiple HPAB was studied from a microscopic perspective using CT scanning and 3D reconstruction technology. The experimental results indicate that (1) With increasing shock by HPAB times, the damage in the area near the blasthole increased linearly, while the damage in the middle and far zones exhibited a slow growth during the first first-third shock by HPAB and a rapid growth during the third-fifth shock by HPAB. The damage in the near blasthole decreased rapidly with increasing distance from the blasthole. Compared with the near blasthole, the cumulative degree of coal damage in the middle and far zones is relatively small. (2) With increasing shock by HPAB times, The time-domain signal of near-field ultrasound changes from a regular waveform to a disordered and distorted waveform, and the amplitude shows a gradually decreasing trend. The main frequency band shifts from high-frequency signals to mid low frequency signals, and the main frequency band signal decreases from 48.48 kHz before HPAB to 4.88 kHz after the fifth shock by HPAB. (3) Compared with before HPAB, After the fifth

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Numerical analysis on mechanical properties and failure mode of GFRP-concrete composite beam 11th

Numerical analysis on mechanical properties and failure mode...

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11th International Conference on Bridge Maintenance, Safety and Management, IABMAS 2022

作者： Chen, Zhaohui Xing, Jiajie Song, Chao Qiao, Yunqiang School of Civil Engineering Chongqing University Chongqing China Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing University Chongqing China Co. Ltd Chongqing China

ISBN: (纸本)9781032345314

Based on the experiments of the GFRP-concrete composite beam, the mechanical property and failure mode of GFRP concrete composite beams are numerically analyzed. Taking into account the anisotropy and stiffness degradation of GFRP, the Hashin criteria is implemented by the VUMAT Model in ABAQUS. The interfacial element by using the bilinear cohesive model is introduced to simulate the bond slip behavior between GFRP flange and concrete slab. The validity of the numerical model is verified by comparing with the results of experimental tests of full GFRP I-profile and GFRP-concrete composite beam. The effects of the strength, thickness, width of concrete slab, and the height of GFRP web on the mechanic performance and failure mode of the composite beam are studied. The results show that the material softening of GFRP and interfacial bond-slip have important influence on the mechanical properties of the composite beam. The increasing strength and thickness of concrete slab would improve the bearing capacity of the composite beam, but excessive compression strength of concrete would lead to longitudinal shear failure of the slab. In addition, the web height of the GFRP profile has a significant effect on the cross-section stress and strain distribution of the composite beam. © 2022 the Author(s).

关键词： Concrete slabs

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Research on dynamic response analysis and evaluation method of resistance to progressive collapse of reinforced concrete frame structures at high temperatures

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Zhendong yu Chongji/Journal of Vibration and Shock 2025年第12期44卷 298-307页

作者： Li, Zhi Huang, Xinhui Ji, Fuquan Zhong, Yu Deng, Xiaofang Guangxi Key Laboratory of Green Building Materials and Construction Industrialization Guilin541004 China School of Civil Engineering Guilin University of Technology Guilin541004 China CCCC Second Harbour Engineering Company Ltd. Wuhan430040 China

To investigate the collapse performance of reinforced concrete (RC) frame structures under high temperatures, ABAQUS finite element software was utilized to establish a finite element model for a two-story RC frame structure with instantaneous corner column removal. Based on the full validation of the model' s accuracy, the study examines the impact of different durations and areas of fire exposure on the dynamic response of the RC frame structure subjected to progressive collapse following corner column failure, through sequential thermo-mechanical coupling modeling. Furthermore, considering the uncertainty of parameters, a probabilistic assessment of the resistance to progressive collapse of RC frame structures under high temperatures was conducted. The results show that with the increase of fire time, when the first layer corner lattice is exposed to fire, the maximum peak displacement of the structure without columns increases by 153. 26% compared with that at room temperature, and its resistance mechanism is mainly cantilever action and vierendeel effect, and the tensile membrane effect occurs when exposed to fire for 60 min. When the first and second floor corner grids are exposed to fire, the maximum peak displacement of the structure after column removal is increased by 145. 81% . Compared with the first layer corner lattice exposed to fire, the vierendeel effect is weakened, but when exposed to fire for 60 min, the floor produces a more obvious tensile membrane effect to resist collapse. Based on the uncertainty of structure and load, the cumulative distribution function obtained by fitting can better evaluate the collapse probability of RC frame structure at high temperature. © 2025 Chinese Vibration engineering Society. All rights reserved.

关键词： ABAQUS

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Determination of surface properties of different formwork release agents on strength concrete

Determination of surface properties of different formwork re...

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作者： Durmuş, Gökhan Çelik, Damla Nur K. Demircan, Rüya Ç. Demirci, Erengül Gazi University Department of Civil Engineering Faculty of Technology Ankara Turkey Sinop University Construction Department Boyabat vocation School Sinop Turkey Gazi University Institute of Science Ankara Turkey

In this study, concrete samples were poured into mold using three different formwork oils and the impact of formwork oil on concrete surface hardness and carbonatization was investigated. 60x60x10 cm3 sized wood formworks were produced by class II pine timber. Three kinds of formwork oils were used such as standard (K1), concentrate (K2) and plywood formwork oils (K3). Concrete blocks were developed by pouring the C20 strength class of concrete into formworks. Concrete surface hardness and carbonatization depths were measured by taking cores giving dimensions of 50x100 mm. The results revealed that the highest surface hardness and carbonatization values were obtained from concentrate formwork oil. The surface hardness was 10 % higher and the carbonatization was 49 % least than oil-free formworks. © 2023

关键词： Compressive strength

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Exploring the relationship between the International Roughness Index (IRI) and the ISO 8608 roughness coefficient (Gd(n0))

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International Journal of Pavement engineering 2024年第1期25卷

作者： Lin, Jeng-Hsiang Department of Civil and Construction Engineering National Taiwan University of Science and Technology Taipei Taiwan Department of Architecture Hwa Hsia University of Technology Taipei Taiwan

Globally, diverse agencies employ varied metrics to gauge road roughness, complicating the exchange of information for pavement maintenance. This study addresses this challenge by establishing a theoretical connection between the International Roughness Index (IRI) and the ISO 8608 Power Spectral Density (PSD)-based roughness coefficient, namely Gd(n0). Based on random vibration theory, this paper first deduces a closed-form explicit solution for IRI related to Gd(n0), solidifying a theoretical link. Next, the variability and convergence of the proposed solution are examined through Monte Carlo simulations using a quarter-car vehicle model with the Golden Car parameters. Then, we compare computed results from this study with those existing solutions from past studies, verifying that the proposed solution captures the curve trend well and agrees with the average value of existing solutions based on field measurement data. Finally, this paper proposes the IRI values corresponding to various ISO road class thresholds and a new Gd(n0) scale for ride quality assessment of highways. © 2024 Informa UK Limited, trading as Taylor & Francis Group.

关键词： Power spectral density

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Experimental on Filling Degree of Horizontal Sleeve Grouting Based on Acoustic Emission technology

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Science technology and engineering 2025年第10期25卷 4256-4264页

作者： Yu, Ai-Ping Shi, Jin-Xu Li, Xiu-Xin Li, Xiang-Hao Deng, Xue-Lian Guangxi Key Laboratory of Green Building Materials and Construction Industrialization Guilin541000 China College of Civil Engineering Guilin University of Technology Guilin541000 China

The evaluation of grouting defects in precast beam grouting sleeves has long been a focal point of scholarly research, with the impact of horizontal defects on performance surpassing that of end and vertical defects. Aiming at the problem of horizontal grouting defect evaluation, the active excitation signal of AST (auto sensor test) and PLB (pencil-lead breakage) function built in acoustic emission instrument was studied, combined with horizontal sleeve grouting fullness test. Through parameter analysis and fast Fourier transform, changes in acoustic emission wave velocity, energy, count and waveform parameters are examined at filling degrees of 50%, 60%, 70%, 80%, 90% and 100% . Furthermore, the correlation between acoustic emission energy, count parameters and main frequency amplitude with grouting fullness was established. The results show that when the excitation source is AST, the acoustic emission energy, count and the main frequency amplitude of its waveform show a good negative exponential correlation with the increase of grouting sleeve fullness, and the combination of the relational equations allows for quantitative acoustic emission analysis and evaluation of grouting fullness of horizontal grouting sleeves. © 2025 Beijing Kexue Jishu yu Gongcheng Zazhishe. All rights reserved.

关键词： Acoustic emissions

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Ground surface vibration response law of different axial charge structures in tunnel hydraulic blasting

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Zhendong Gongcheng Xuebao/Journal of Vibration engineering 2025年第1期38卷 172-179页

作者： Zhao, Licai The Third Engineering Co. Ltd. China Railway 19th Bureau Group Corporation Limited Shenyang110136 China Department of Civil and Construction Engineering National Taiwan University of Science and Technology Taipei10607 Taiwan

To investigate the influences of charge structures on the blast-induced ground vibration characteristics in hydraulic blasting，several onsite experiments were conducted in the context of Xinbin tunnel at the Shenyang to Jilin Expressway. Based on the onsite experiments，the peak particle velocity（PPV）and dominant frequency（DF）were analyzed under different kinds of charge structures，which includes the normal charge structure，the water bags located in the top of blasthole，the water bags located in the blasthole collar and the water bags located in the both ends of blasthole. In addition，the distribution laws of ground vibration under different charge structures were further studied using numerical simulation. The research results indicated that，compared with the normal charge structures，less explosive energy is converted into vibration energy in hydraulic blasting，resulting in smaller PPVs and higher DFs. Within 5 m of the cross section along the tunnel excavation face，the PPVs of blasting vibration under the normal charge structure exceed the vibration safety criteria，which is adverse for the safety control of ground structures. The converted vibration energy is relatively smaller along the direction of water bags in blasthole，but on the opposite direction of the blastholes more explosive energy is converted into vibration energy. In tunnel blasting excavation，the charge structure of the water bags located in the both ends of blasthole was recommended to promote the uniform distribution of vibration energy and minimize the disturbance to the surrounding structures. © 2025 Nanjing University of Aeronautics an Astronautics. All rights reserved.

关键词： Blasting

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Analysis of Shear Deformation of Column Structure Based on Load Equivalent Distribution Theory

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Zhendong Ceshi Yu Zhenduan/Journal of Vibration, Measurement and Diagnosis 2024年第5期44卷 1023-1031and1044页

作者： Zhao, Licai Department of Civil and Construction Engineering National Taiwan University of Science and Technology Taipei106335 Taiwan The Third Engineering Co. Ltd. of China Railway 19th Bureau Group Shenyang110136 China

To enhance the calculation efficiency and accuracy of shear deformation in column structures with Timoshenko beam properties, an equivalent distributed load-finite element method is proposed, based on the theory of equivalent load distribution, node analysis method, and Timoshenko beam theory with orthogonal Interpolation characteristics. This method efficiently addresses the shear deformation displacement of beam-column joints, which is more accurate and efficient than existing algorithms in analyzing the shear deformation of the column structure. The reliability of the equivalent distributed load-finite element algorithm is verified through the study of two working cases, and the results demonstrate that highly accurate Solutions of displacement, angles of rotation, shear forces, and bending moment can be obtained using very few elements (one or two ele-ments). In contrast, other displacemenCbased methods, such as simplified Integration, require about 40 elements to achieve comparable results. This method can directly and systematically determine the stability func-tion and bending load of Timoshenko bearrrcolumn under different connection conditions, which effectively im_ prove the accuracy of finite element analysis Solution of shear deformation of column structure. © 2024 Nanjing University of Aeronautics an Astronautics. All rights reserved.

关键词： Shear deformation

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Recent advancement and future challenges of photothermal catalysis for VOCs elimination:From catalyst design to applications

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Green Energy & Environment 2023年第3期8卷 654-672页

作者： Yang Yang Shenghao Zhao Lifeng Cui Fukun Bi Yining Zhang Ning Liu Yuxin Wang Fudong Liu Chi He Xiaodong Zhang Environment and Low-Carbon Research Center School of Environment and ArchitectureUniversity of Shanghai for Science and TechnologyShanghai 200093China College of Smart Energy Shanghai Jiao Tong UniversityShanghai 200240China Institute of Applied Biotechnology Taizhou Vocation&Technical CollegeTaizhou Zhejiang 318000China Department of Civil Environmentaland Construction EngineeringCatalysis Cluster for Renewable Energy and Chemical Transformations(REACT)NanoScience Technology Center(NSTC)University of Central FloridaOrlandoFL 32816United States State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power EngineeringXi'an Jiaotong UniversityXi'anShaanxi 710049China

Photothermal catalysis realizes the synergistic effect of solar energy and thermochemistry,which also has the potential to improve the reaction rate and optimize the *** this review,the research progress of photothermal catalytic removal of volatile organic compounds(VOCs)by nano-catalysts in recent years is systematically ***,the fundamentals of photothermal catalysis and the fabrication of catalysts are described,and the design strategy of optimizing photothermal catalysis performance is ***,the performance for VOC degradation with photothermal catalysis is evaluated and compared for the batch and continuous ***,the catalytic mechanism of VOC oxidation is systematically introduced based on experimental and theoretical ***,the future limitations and challenges have been discussed,and potential research directions and priorities are highlighted.A broad view of recent photothermal catalyst fabrication,applications,challenges,and prospects can be systemically provided by this review.

关键词： Photothermal catalysis VOCs Catalyst design Light-driven thermal catalysis Photothermal synergistic effect

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