Experimental Investigation on Fatigue Improvement of Orthotropic Steel Bridge Deck Using Steel Fiber Reinforced Concrete

Huawen Ye,Ao Huang,Chengchuan Jiang,Wenchao Wang 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.5

The high-performance topping concrete overlay would significantly reduce the fatigue stresses at susceptible details of orthotropic steel deck (OSD) and effectively improve the fatigue performance. Full-scale fatigue tests and numerical simulations were carried out to quantify the effects of steel fiber reinforced concrete (SFRC) topping pavement in reducing the OSD fatigue stresses based on a practical bridge design. Fatigue stress of the OSD critical details was measured from tests and cracking was observed in the SFRC overlay. Both an innovative pre-pump-pulse Brillouin optical time domain analysis (PPP-BOTDA) distributed optical fiber sensor and strain gauges were also used to measure the stress at OSD fatigue-prone details, including the crossbeam cut-out, rib-to-deck weld, rib-to-crossbeam weld and splice of U-rib. The corresponding three-dimensional (3-D) finite element model was then established and verified by the test results, and used to conduct a parametric study to obtain a quantitative expression of fatigue stress reduction factor, in terms of relative elastic modulus and thickness of overlay and steel deck plate. The proposed quantitative model of the fatigue stress reduction effect can guide the cost-effective design of composite bridge deck.

Determination of shear stiffness for headed-stud shear connectors using energy balance approach

Huawen Ye,Ruosen Huang,Shiqing Tang,Yu Zhou,Jilin Liu 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.42 No.4

The shear stiffness of headed-stud shear connectors has no unified definition due to the nonlinear characteristics of its load-slip relationship. A unified framework was firstly adopted to develop a general expression of shear load-slip equation for headed-stud shear connectors varying in a large parameter range based on both force and energy balance. The pre- and postyield shear stiffness were then determined through bilinear idealization of proposed shear load-slip equation. An updated and carefully selected push-out test database of 157 stud shear connectors, conducting on studs 13~30mm in diameter and on concretes 30~180 MPa in cubic compressive strength, was used for model regression and sensitivity analysis of shear stiffness. An empirical calculation model was also established for the stud shear stiffness. Compared with the previous models through statistical analysis, the proposed model demonstrates a better performance to predict the shear load-slip response and stiffness of the stud shear connectors.

A Unifi ed Theory for Distortion Analysis of Thin-Walled Hollow Sections

Xun Xu,Huawen Ye,De-Yi Zhang,Shizhong Qiang 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.3

A novel unifi ed theory for distortion analysis of thin-walled hollow section has been proposed based on the Hellinger– Reissner variational principle to account for distortional shear deformation eff ects. Based on the proposed theory, a fi nite segment model has been developed and the method for determining the distortion functions of the cross-section has been proposed. The rationality of approaches for determining distortional shear stress has been analysed and it is concluded that Bredt’s pure distortion does not exist in the single-cell hollow section. Comparisons and analyses have been performed between the proposed theoretical model and the existing four groups of theories in distortion analysis of thin-walled hollow section. Eff ects of distortional warping shear stress on the shear deformation has been investigated and the results indicate that the distortional shear deformation eff ect results in a decrease of the distortional warping stresses and shear stresses but an increase of the transverse bending stresses. The numerical study indicates that the distortional shear deformation eff ects can be ignored and the fi rst derivative of the distortion angle can be employed as the distortional warping function for the conventional hollow sections of bridge structures.

Sensitive Optical Probe for Hydrogen Peroxide Using Carbon Quantum Dots Synthesized by Glutathione

Qing Huang,Huawen Zhao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.7

Herein, we present the one-pot synthesis of carbon quantum dots (CQDs) using glutathione and used for the optical detection of hydrogen peroxide (H2O2). Unlike as reported in other literatures, the detection of H2O2 is free of using any additional chromogenic agents or metal ions. The CQDs are synthesized using glutathione by one-pot hydrothermal at 180 ℃. The as-prepared CQDs exhibit good fluorescence response toward H2O2 without involving extra chromogenic substances. The addition of 300 μM H2O2 to CQDs induces the quenching of fluorescence, besides the yellow becomes colorless. The decrease in the fluorescence is attributed to the polymeric structure of CQDs disbanded by H2O2. In addition, the practical application of the present method was verified by determining H2O2 in human urine samples.

Analytical Solution for Horizontal Tension of Main Cable in Erection of Stiffening Girder

Cuijuan Li,Huawen Ye,Maolin Tang,Xiaomin Yuan 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.10

The horizontal tension of main cable is a key parameter to guarantee the safety of tower, form gravity stiffness and keep main cable shape correct during erection of stiffening girders. Instead of complicated Finite Element Modeling and iterative algorithms, simply analytical solutions of horizontal tension of main cable were deduced for two classical erection methods of stiffening girder based on the mathematical analogue and work-energy principle. Numerical method was also adopted to verify the analytical solutions on analysis of a single span suspension bridge. The results from analytical solution are found to be in good agreement with the numerical results. The theoretical results show that the presented analytical solutions can be easily applied in the calculation of the horizontal tension of main cable in any erection stage.

Petrogenesis of the late Mesozoic highly fractionated I-type granites in the Luanchuan district: implications for the tectono-magmatic evolution of eastern Qinling

Yunhui Zhang,Huawen Cao,Mo Xu,Shouting Zhang,Li Tang,Shiyan Wang,Qiuming Pei,Guojun Cai,Tong Shen 한국지질과학협의회 2018 Geosciences Journal Vol.22 No.2

Late Mesozoic granites are extensively distributed in the Luanchuan district of eastern Qinling and can be divided into two types: Late Jurassic to Early Cretaceous granites (ore-related plutons) and Late Cretaceous granites (Laojunshan batholith). This study presents new geochemical and zircon U-Pb-Hf isotopic data from the Shibaogou and Yuku plutons to provide robust constraints on the petrogenesis and tectonic significance of the late Mesozoic granites in the Luanchuan district. Zircon U-Pb dating results yielded weighted mean 206Pb/238U ages of 149.1 ± 0.8 Ma and 150.5 ± 0.8 Ma, which were interpreted as the crystallization ages of the Shibaogou and Yuku plutons, respectively. We propose that the late Mesozoic granites contain high concentrations of SiO2 and alkali elements (Na2O + K2O) and feature metaluminous to weakly peraluminous characteristics. Enrichment in light rare earth elements and large ion lithophile elements and depletion in high field strength elements are observed. Mineralogical and geochemical evidence reveal that the late Mesozoic granites are highly fractionated I-type granites with fractional crystallization of feldspar, plagioclase and accessory minerals (e.g., apatite and titanite or magnetite). Based on the Hf composition, we suggest that the parental magmas of the ore-related plutons were derived from remelting of the Taihua and Xiong’er groups with minor contributions of mantle-derived materials and that the Laojunshan batholith was generated by the hybridization of ancient crust- (Kuanping group) and mantle-derived components. Collectively, the above arguments indicates a tectonic transition from compression to post-collisional extension during the late Mesozoic, that was likely triggered by the continental collision of the North China Block and the Yangtze Block, which generated numerous contemporaneous granites and Mo-W-Pb-Zn-Ag-Au poly-metallic deposits.

Stabilization of Benchmark Under-actuated Systems via Saturated Controls

Jun Liu,Huawen Ye,Xianting Qi 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.11

In this paper, we present controllers to stabilize benchmark under-actuated systems such as inertia wheel pendulum (IWP), cart-pole, cart-pendulum, overhead crane, VTOL aircraft, ball-and-beam, translational oscillations with a rotational actuator (TORA), and active magnetic bearing (AMB). The mentioned systems are transformed into the feedforward systems subject to uncertain gains, the nested-saturation controllers in an almost unified form are then designed. Due to the analysis mechanism of saturation reduction (checking the time-derivatives of boundary surfaces), the bounds of uncertain gains can always be determined in small domains. In turn, there is no need to treat in advance certain subsystems, and the fully-saturated controllers (rather than partially-saturated ones) can be taken as global stabilizers. Moreover, the explicit inequality conditions can always be summarized. In addition, for the relatively complicated systems such as the overhead crane system, a non-strict upper-triangular subsystem of the ball-and-beam system as well as the TORA system, special technical strategies are developed to treat the linear perturbation, the non-strict upper-triangular structure and an oscillator.

Identification of DNA methylation associated gene signatures in endometrial cancer via integrated analysis of DNA methylation and gene expression systematically

Chuandi Men,Hongjuan Chai,Xumin Song,Yue Li,Huawen Du,Qing Ren 대한부인종양학회 2017 Journal of Gynecologic Oncology Vol.28 No.6

Objective: Endometrial cancer (EC) is a common gynecologic cancer worldwide. However,the pathogenesis of EC has not been epigenetically elucidated. Here, this study aimsto describe the DNA methylation profile and identify favorable gene signatures highlyassociated with aberrant DNA methylation changes in EC. Methods: The data regarding DNA methylation and gene expression were downloaded fromThe Cancer Genome Atlas (TCGA) database. Differentially methylated CpG sites (DMCs),differentially methylated regions (DMRs), and differentially expressed genes (DEGs) wereidentified, and the relationship between the 2 omics was further analyzed. In addition,weighted CpG site co-methylation network (WCCN) was constructed followed by anintegrated analysis of DNA methylation and gene expression data. Results: Four hundred thirty-one tumor tissues and 46 tissues adjacent tumor of EC patientswere analyzed. One thousand one hundred thirty-five DMCs (merging to 10 DMRs), and1,488 DEGs were obtained between tumor and normal groups, respectively. One hundredforty-eight DMCs-DEGs correlated pairs and 13 regional DMCs-DEGs pairs were obtained. Interestingly, we found that some hub genes in 2 modules among 8 modules of WCCNanalysis were down-regulated in tumor samples. Furthermore, protocadherins (PCDHs)clusters, DDP6, TNXB, and ZNF154 were identified as novel deregulated genes with alteredmethylation in EC. Conclusion: Based on the analysis of DNA methylation in a systematic view, the potentiallong-range epigenetic silencing (LRES) composed of PCDHs was reported in ECs for the firsttime. PCDHs clusters, DDP6, and TNXB were firstly found to be associated with tumorigenesis,and may be novel candidate biomarkers for EC.