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Science China Technological Sciences 2025年第1期 233-250页

作者： S.Aravind KRISHNA N.RADHIKA Alokesh PRAMANIK N.JEYAPRAKASH Department of Mechanical engineering Amrita School of EngineeringAmrita Vishwa Vidyapeetham school of civil and Mechanical engineering Curtin University school of Mechanical and Electrical engineering China University of Mining and Technology

The ability to perform against extreme corrosion environments in stainless steel depreciates under challenging conditions in industrial applications. This can be resolved by employing surface modification techniques to modify the surface with the required characteristics. The present study investigates the outcomes of friction stir processing of SS304 with CoCrFeCuTi high entropy alloy(HEA) as reinforcement and the property enhancements post-annealing. The synthesized CoCrFeCuTi HEA exhibited irregular fragments with 17 μm mean particle size and body centred cubic(BCC) phase. The microstructure of the processed surface revealed ultra-refined grains with a uniform distribution of HEA filler. The microstructures of the samples annealed at 400℃, 550℃, 700℃ and 850℃ for 2 h also showed significant grain growth and grain refinements. The processed sample with HEA reinforcement annealed at 700℃ exhibited enhanced microhardness and tensile strength by 63% and 0.88 times than that of the processed sample with HEA pre-annealing. The subsequent electrochemical corrosion test displayed better corrosion resistance for the HEA-processed and annealed sample. Hot corrosion tests at 900℃ showcased excellent resistance for the HEA processed and annealed samples by 14.92%, 12.75%, and 14.83% against the samples pre-annealed under three different salt mixtures, and the corroded surface was analyzed.

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Heterogeneous traffic flow modeling with drivers’ timid and aggressive characteristics

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Chinese Physics B 2021年第10期30卷 219-230页

作者： Cong Zhai Weitiao Wu Songwen Luo school of civil engineering and transportation South China University of TechnologyGuangzhou 510641China school of transportation and civil engineering and Architecture Foshan UniversityFoshan 528000China

The driver’s characteristics(e.g.,timid and aggressive)has been proven to greatly affect the traffic flow performance,whereas the underlying assumption in most of the existing studies is that all drivers are *** the real traffic environment,the drivers are distinct due to a variety of factors such as personality *** better reflect the reality,we introduce the penetration rate to describe the degree of drivers’heterogeneity(i.e.,timid and aggressive),and proceed to propose a generalized heterogeneous car-following model with different driver’s *** the linear stability analysis,the stability conditions of the proposed heterogeneous traffic flow model are obtained based on the perturbation *** impacts of the penetration rate of drivers with low intensity,the average value and standard deviation of intensity parameters characterizing two types of drivers on the stability of traffic flow are analyzed by *** show that higher penetration of aggressive drivers contributes to traffic flow *** average value has a great impact on the stability of traffic flow,whereas the impact of the standard deviation is trivial.

关键词： heterogeneous car-following model driver characteristic penetration rate stability

High order multiplication perturbation method for singular perturbation problems

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Applied Mathematics and Mechanics(English Edition) 2013年第11期34卷 1383-1392页

作者：张文志黄培彦 school of civil and transportation engineering South China University of Technology

This paper presents a high order multiplication perturbation method for sin- gularly perturbed two-point boundary value problems with the boundary layer at one end. By the theory of singular perturbations, the singularly perturbed two-point boundary value problems are first transformed into the singularly perturbed initial value problems. With the variable coefficient dimensional expanding, the non-homogeneous ordinary dif- ferential equations （ODEs） are transformed into the homogeneous ODEs, which are then solved by the high order multiplication perturbation method. Some linear and nonlinear numerical examples show that the proposed method has high precision.

关键词： singular perturbation problem (SPP). high order multiplication perturba-tion method two-point boundary value problem boundary layer

Numerical analysis and field monitoring tests on shallow tunnels under weak surrounding rock

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Journal of Central South university 2015年第10期22卷 4056-4063页

作者：刘建华刘晓明张永杰肖庭 school of Traffic and transportation engineering Changsha University of Science and Technology College of civil engineering Hunan University school of civil engineering and Architecture Changsha University of Science and Technology

The Jianpudong No. 4 tunnel is a shallow tunnel, which belongs to Shaoshan County scenic highway in Hunan province, China and whose surrounding rock is weak. According to its characteristics, the field monitoring tests and numerical analysis were done. The mechanical characteristics of shallow tunnels under weak surrounding rock and the stress-strain rule of surrounding rock and support were analyzed. The numerical analysis results show that the settlement caused by upper bench excavating accounts for 44% of the total settlement, and the settlement caused by tunnel upper bench supporting accounts for 56% of the total settlement. The maximum axial force of shotcrete lining is 177.2 k N, which locates in hance under the secondary lining. The maximum moment of shotcrete lining is 5.08 k N·m, which locates in the arch foot. The stress curve of steel arch has three obvious stages during the tunnel construction. The maximum axial force of steel arch is 297.4 k N, which locates in tunnel vault. The axial forces of steel arch are respectively 23.5 k N and-21.8 k N, which is influenced by eccentric compression of shallow tunnel and locates in hance. The results show that there is larger earth pressure in tunnel vault which is most unfavorable position of steel arch. Therefore, the advance support should be strengthened in tunnel vault during construction process.

关键词： tunnel engineering shallow tunnel weak surrounding rock numerical analysis field monitoring tests

Large-scale direct shear testing of geocell reinforced soil

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Journal of Central South university of technology 2008年第6期15卷 895-900页

作者：汪益敏陈页开刘炜 school of civil and transportation engineering South China University of Technology

The tests on the shear property of geocell reinforced soils were carried out by using large-scale direct shear equipment with shear-box-dimensions of 500 mm×500 mm×400 mm (length×width×height). Three types of specimens, silty gravel soil, geocell reinforced silty gravel soil and geocell reinforced cement stabilizing silty gravel soil were used to investigate the shear stress-displacement behavior, the shear strength and the strengthening mechanism of geocell reinforced soils. The comparisons of large-scale shear test with triaxial compression test for the same type of soil were conducted to evaluate the influences of testing method on the shear strength as well. The test results show that the unreinforced soil and geocell reinforced soil give similar nonlinear features on the behavior of shear stress and displacement. The geocell reinforced cement stabilizing soil has a quasi-elastic characteristic in the case of normal stress coming up to 1.0 GPa. The tests with the reinforcement of geocell result in an increase of 244% in cohesion, and the tests with the geocell and the cement stabilization result in an increase of 10 times in cohesion compared with the unreinforced soil. The friction angle does not change markedly. The geocell reinforcement develops a large amount of cohesion on the shear strength of soils.

关键词： direct shear test geocell reinforced soil shear strength cohesion

Micromechanical analysis of damage evolution in splitting test of asphalt mixtures

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Journal of Central South university 2010年第3期17卷 628-634页

作者：陈页开虞将苗张肖宁 school of civil engineering and transportation South China University of Technology

A methodology was presented relating the microstructure of asphalt mixtures to their damage behavior. Digital image techniques were used to capture the asphalt mixture microstructure, and the finite element method was used to simulate the damage evolution of asphalt mixture through splitting test. Aggregates were modeled to be linearly elastic, and the mastics were modeled to be plastically damaged. The splitting test simulation results show that the material heterogeneity, the properties of aggregates and air voids have significant effects on the damage evolution approach. The damage behavior of asphalt mixture considering material heterogeneity is quite different from that of the conventional hypothesis of homogeneous material. The results indicate that the proposed method can be extended to the numerical analysis for the other micromechanical behaviors of asphalt concrete.

关键词： asphalt mixture digital image techniques X-ray computerized tomography finite element method damage behavior

Width effects on hydrodynamics of pendulum wave energy converter

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Applied Mathematics and Mechanics(English Edition) 2014年第9期35卷 1167-1176页

作者：王冬姣邱守强叶家玮 school of civil engineering and transportation South China University of Technology

Based on two- and three-dimensional potential flow theories, the width effects on the hydrodynamics of a bottom-hinged trapezoidal pendulum wave energy converter are discussed. The two-dimensional eigenfunction expansion method is used to obtain the diffraction and radiation solutions when the converter width tends to be infinity. The trapezoidal section of the converter is approximated by a rectangular section for simplification. The nonlinear viscous damping effects are accounted for by including a drag term in the two- and three-dimensional methods. It is found that the three- dimensional results are in good agreement with the two-dimensional results when the converter width becomes larger, especially when the converter width is infinity, which shows that both of the methods are reasonable. Meantime, it is also found that the peak value of the conversion efficiency decreases as the converter width increases in short wave periods while increases when the converter width increases in long wave periods.

关键词： pendulum wave energy converter two-dimensional eigenfunction expansion method three-dimensional potential flow theory wave energy conversion efficiency

Tensile Fracture Mechanism of Claviform Hybrid Composite Rebar

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Journal of Wuhan university of technology(Materials Science) 2012年第3期27卷 501-506页

作者：蔡禄荣 school of civil engineering and transportation South China University of Technology

Based on the shear-lag theory, a hexagonal model of fiber bundles was established to study the tensile fracture mechanism of a claviform hybrid composite rebar. Firstly, the stress redistributions are investigated on two conditions： one condition is that interfacial damage is taken into account and the other is not. Then, a micro-statistical analysis of the multiple tensile failures of the rebar was performed by using the random critical-core theory. The results indicate that the predictions of the tensile failure strains of the rebar, in which the interfacial damage is taken into account, are in better agreement with the existing experimental results than those when only elastic case is considered. Through the comparison between the theoretical and experimental results, the shear-lag theory and the model are verified feasibly in studying the claviform hybrid composite rebar.

关键词： hybrid composite rebar tensile failure shear-lag analysis stress redistribution statistical analysis

Coupling of high order multiplication perturbation method and reduction method for variable coefcient singular perturbation problems

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Applied Mathematics and Mechanics(English Edition) 2014年第1期35卷 97-104页

作者：张文志黄培彦 school of civil and transportation engineering South China University of Technology

Based on the precise integration method （PIM）, a coupling technique of the high order multiplication perturbation method （HOMPM） and the reduction method is proposed to solve variable coefficient singularly perturbed two-point boundary value prob lems （TPBVPs） with one boundary layer. First, the inhomogeneous ordinary differential equations （ODEs） are transformed into the homogeneous ODEs by variable coefficient dimensional expansion. Then, the whole interval is divided evenly, and the transfer ma trix in each sub-interval is worked out through the HOMPM. Finally, a group of algebraic equations are given based on the relationship between the neighboring sub-intervals, which are solved by the reduction method. Numerical results show that the present method is highly efficient.

关键词： high order multiplication perturbation method (HOMPM) reductionmethod variable coefficient singular perturbation problem two-point boundary valueproblem

A New Method for Determining Threshold in Using PGCEVD to Calculate Return Values of Typhoon Wave Height

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China Ocean engineering 2012年第2期26卷 251-260页

作者：罗耀朱良生胡金鹏 school of civil engineering and transportation South China University of Technology

In using the PGCEVD （Poisson-Gumbel Compound Extreme Value Distribution） model to calculate return values of typhoon wave height, the quantitative selection of the threshold has blocked its application. By analyzing the principle of the threshold selection of PGCEVD model and in combination of the change point statistical methods, this paper proposes a new method for quantitative calculation of the threshold in PGCEVD model. Eleven samples from five engineering points in several coastal waters of Guangdong and Hainan, China, are calculated and analyzed by using PGCEVD model and the traditional Pearson type III distribution （P-III） model, respectively. By comparing the results of the two models, it is shown that the new method of selecting the optimal threshold is feasible. PGCEVD model has more stable results than that of P-III model and can be used for the return wave height in every direction.

关键词： POT Compound Extreme Value Distribution Pearson type II1 mean change point extreme wave height