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Distributed fiber optic sensing system for vibration monitoring of 3D printed bridges

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Optoelectronics Letters 2025年第1期21卷 28-34页

作者： ZHAO Shuai ZHOU Ran LUO Mingming LIU Jianfei LIU Xiongfei ZHOU Tao School of Electronic Information engineering Hebei University of Technology Tianjin Key Laboratory of Electronic Materials and Devices School of civil engineering and transportation Hebei University of Technology Tianjin Jinhang Institute of Technical Physics

The fiber optic sensing technology provides data support in structural health monitoring of the macro facilities, including design, construction, and maintenance of bridges, tunnels, ports and other infrastructures. In this paper, a distributed vibration sensing system is proved to be responsive to a single touch over a 1.8-m-long equivalent fiber segment, covering a vibration frequency from 5 Hz to 25 kHz. The sensing fiber was arranged as an S type layout on the bridge to recognize the standing state, windblown disturbance, and walking vibration. Moreover, the knocking and climbing events are recognized fiber laying spinning lines and hanging on the fences, respectively. The demonstration shows an accurate positioning and sensitive vibration monitoring applied on the automated three-dimensional(3D) printed bridge, which is applicable to all kinds of 3D printed facilities as intelligent sensory neuro-networks.

关键词： Spinning (fibers)

Insight into the particle shape on the impact of dry granular flow against a rigid barrier: A DEM study

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Journal of Earth Science 2025年

作者： Rui-Xiao Zhan Dong Su Xiang-Sheng Chen Yuan-Jun Jiang Guo-Ping Lei Jing-Jing Yu Key Laboratory for Resilient Infrastructures of Coastal Cities (MOE)， Shenzhen University College of civil and transportation engineering， Shenzhen University School of Architecture and Urban Planning， Shenzhen University Shenzhen Key Laboratory of Green， Efficient and Intelligent Construction of Underground Metro Station， Shenzhen University Institute of Mountain Hazards and Environment， Chinese Academy of Sciences School of transportation， civil engineering & Architecture， Foshan University

The effect of particle shape on the impact of dry granular flow remains an open area for further investigation. Five distinct particle shapes were examined in this study using discrete element simulations after calibrating the numerical model using a published work. The findings indicated that the particle shape had a significant influence on granular mobility. With negligible variations in normalized kinetic energy between particles of different shapes， the effect of particle shape on the increasing rate of kinetic energy became more obvious. All irregular particle scenarios had longer accumulated particle lengths down the channel than spherical particles. Variations in particle shape led to adjustments in the distribution of impact forces on the barrier. These findings substantially enhance our understanding of the distinctive effects of particle shapes on the impact mechanism of dry granular flow.

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Stability analysis of cut-fill and deep patch unsaturated slopes under steady infiltration conditions

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Science China Technological Sciences 2025年第1期 356-367页

作者： Fei ZHANG Shilin JIA Yufeng GAO Key Laboratory of the Ministry of Education for Geomechanics and Embankment engineering College of Civil and Transportation EngineeringHohai University

Cut-fill slopes, as an economical solution in mountainous road construction, are typically jeopardized by cracks and rainfall. Deep patch repair with geosynthetics is an effective technique to mitigate these issues. This paper proposes an upperbound analytical framework for evaluating the stability of cracked cut-fill slopes and deep patch slopes under one-dimensional steady infiltration. The proposed framework is employed to investigate suction-induced effects on slope stability and critical failure surface through a series of parametric analyses. The findings indicate that the suction-induced effect generally increases with air-entry pressure and approaches a constant value. The stability of a cracked cut-fill slope can be enhanced by deep patch repair with geosynthetics. Increasing the deep patch depth enhances local stability and reduces the required reinforcement strength. Generally, the depth of the deep patch should be greater than the crack depth to avoid local failures. Furthermore, a design method involving both local and global stability for deep patch slopes is presented, along with a design example for illustration.

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Exploring the factors affecting electric bicycle riders'working conditions and crash involvement in Ningbo,China

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Journal of Traffic and transportation engineering(English Edition) 2023年第4期10卷 633-646页

作者： Jibiao Zhou Ying Shen Yanyong Guo Sheng Dong School of civil and transportation engineering Ningbo University of TechnologyNingbo 315211China College of transportation engineering Tongji UniversityShanghai 201804China chool of civil and transportation engineering Hebei University of TechnologyTianjin 300130China School of transportation Southeast UniversityNanjing 211189China

The rapid development of the delivery industry brings convenience to modern ***,the high rates of crashes and the survival of electric bicycle(e-bike)riders in the delivery industry raise *** primary objective of this study is to explore the factors affecting delivery e-bike riders’stressful work pressure and crash involvement in *** were collected by a questionnaire survey administered in the city of Ningbo,China.A bivariate ordered probit(BOP)model was developed to simultaneously examine the factors associated with both the working conditions of delivery e-bike riders and their involvement in *** marginal effects for the contributory factors were calculated to quantify their impacts on the *** results showed that the BOP model can account for commonly unobserved characteristics of the working conditions and crash involvement of delivery e-bike *** BOP model results showed that the stressful working conditions of delivery e-bike riders were affected by the number of orders and delivery time and rider age and risky riding *** rider involvement in crashes was affected by the number of orders,strength of the punishment for traffic violations,and familiarity with traffic *** was also found that stressful working conditions and crash involvement were strongly and positively *** findings of this study can enhance our understanding of the factors that affect the working conditions and delivery rider crash *** on the results,some suggestions regarding public policy,risky riding behaviors,safety promotion,and stronger corporate governance rules were discussed to increase the targeted safety-related interventions for delivery ebike riders in Ningbo,China.

关键词： Traffic safety Stressful working conditions Bivariate ordered probit model Electric bicycleriders Crash involvement Delivery e-bike

Bound analysis of target displacement for seismic performance assessment of buildings

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Journal of Harbin Institute of Technology(New Series) 2008年第1期15卷 27-32页

作者：贾立哲段忠东陆钦年 chool of civil engineering Harbin Institute of Technology

The earthquake demand spectrum is often assumed as the average spectrum in the seismic design code or based upon probabilistic models to take into account the uncertainties of ground motion. The average spectrum can not deal with the uncertainty of earthquake excitation. Furthermore, results of probabilistic analysis are suspicious when information describing the uncertainty is inadequate. Considering the uncertainties of peak acceleration of ground motion and characteristic period of response spectra using a double bounded convex set model, the bounds of the design spectrum and the demand spectrum were obtained based on Chinese seismic code. Then the convex analysis method was integrated into the capacity spectrum procedure to study the bound characteristics of target displacement. Finally, the target displacement was derived with an interval, and it is more objective and robust with respect to probabilistic perspective.

关键词： convex set model capacity spectrum method uncertainty

Effect of strain rate and water-to-cement ratio on compressive mechanical behavior of cement mortar

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Journal of Central South University 2015年第3期22卷 1087-1095页

作者：周继凯葛利梅 College of civil and transportation engineering Hohai University

Effects of strain rate and water-to-cement ratio on the dynamic compressive mechanical behavior of cement mortar are investigated by split Hopkinson pressure bar(SHPB) tests. 124 specimens are subjected to dynamic uniaxial compressive *** rate sensitivity of the materials is measured in terms of failure modes, stress-strain curves, compressive strength, dynamic increase factor(DIF) and critical strain at peak stress. A significant change in the stress-strain response of the materials with each order of magnitude increase in strain rate is clearly seen from test results. The slope of the stress-strain curve after peak value for low water-to-cement ratio is steeper than that of high water-to-cement ratio mortar. The compressive strength increases with increasing strain rate. With increase in strain rate, the dynamic increase factor(DIF) increases. However, this increase in DIF with increase in strain rate does not appear to be a function of the water-to-cement ratio. The critical compressive strain increases with the strain rate.

关键词： cement mortar loading rate compressive strength critical strain stress-strain behavior

Bending behaviour of lightweight aggregate concrete-filled steel tube spatial truss beam

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Journal of Central South University 2016年第8期23卷 2110-2117页

作者：傅中秋吉伯海朱伟葛汉彬 College of civil and transportation engineering Hohai University Department of civil engineering Meijo University

A lightweight aggregate concrete-filled steel tube(LACFST) spatial truss beam was tested under bending load. The performance was studied by the analysis of the beam deflection and strains in its chords and webs. According to the test results, several assumptions were made to deduce the bearing capacity calculation method based on the force balance of the whole section. An optimal dimension relationship for the truss beam chords was proposed and verified by finite element analysis. Results show that the LACFST spatial truss beam failed after excessive deflection. The strain distribution agreed with Bernoulli-Euler theoretical prediction. The truss beam flexural bearing capacity calculation results matched test evidence with only a 3% difference between the two. Finite element analyses with different chord dimensions show that the ultimate bearing capacity increases as the chord dimensions increase when the chords have a diameter smaller than optimal one; otherwise, it remains almost unchanged as the chord dimensions increase.

关键词： lightweight aggregate concrete-filled steel tube spatial truss beam bending behaviour bearing capacity

Study of heat treatment parameters for large-scale hydraulic steel gate track

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Water Science and engineering 2013年第4期6卷 423-432页

作者： Ping-zhou CAO Guang-zhong LIU Kai WU College of civil and transportation engineering Hohai University

In order to enhance external hardness and strength, a large-scale hydraulic gate track should go through heat treatment. The current design method of hydraulic gate wheels and tracks is based on Hertz contact linear elastic theory, and does not take into account the changes in mechanical properties of materials caused by heat treatment. In this study, the heat treatment parameters were designed and analyzed according to the bearing mechanisms of the wheel and track. The quenching process of the track was simulated by the ANSYS program, and the temperature variation, residual stress, and deformation were obtained and analyzed. The metallurgical structure field after heat treatment was predicted by the method based on time-temperatuxe-transformation （TTT） curves. The results show that the analysis method and designed track heat treatment process are feasible, and can provide a reference for practical projects.

关键词： steel gate track heat treatment parameter residual deformation numerical simulation

Moisture effect on compressive behavior of concrete under dynamic loading

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Journal of Central South University 2014年第12期21卷 4714-4722页

作者：周继凯丁宁 College of civil and transportation engineering Hohai University

The effect of moisture content upon compressive mechanical behavior of concrete under impact loading was studied. The axial rapid compressive loading tests of over 50 specimens with five different saturations were executed. The technique "split Hopkinson pressure bar"(SHPB) was used. The impact velocity was 10 m/s with corresponding strain rate of 50 s-1. The compressive behavior of materials was measured in terms of stress-strain curves, dynamic compressive strength, dynamic increase factor(DIF) and critical strain at a maximum stress. The data obtained from test indicate that both ascending and descending portions of stress-stain curves are affected by moisture content. However, the effect is noted to be more significant in ascending portion of the stress-strain curves. Dynamic compressive strength is higher at lower moisture content and weaker at higher moisture ***, under nearly saturated condition, an increase in compressive strength can be found. The effect of moisture content on the average DIF of concrete is not significant. The critical compressive strain of concrete does not change with moisture content.

关键词： concrete split Hopkinson pressure bar high strain rate compressive behavior moisture content