Deflection calculation method on GFRP-concrete-steel composite beam

Zhaojie Tong,Xiaodong Song,Qiao Huang 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.5

A calculation method was presented to calculate the deflection of GFRP-concrete-steel beams with full or partial shear connections. First, the sectional analysis method was improved by considering concrete nonlinearity and shear connection stiffness variation along the beam direction. Then the equivalent slip strain was used to take into consideration of variable crosssections. Experiments and nonlinear finite element analysis were performed to validate the calculation method. The experimental results showed the deflection of composite beams could be accurately predicted by using the theoretical model or the finite element simulation. Furthermore, more finite element models were established to verify the accuracy of the theoretical model, which included different GFRP plates and different numbers of shear connectors. The theoretical results agreed well with the numerical results. In addition, parametric studies using theoretical method were also performed to find out the effect of parameters on the deflection. Based on the parametric studies, a simplified calculation formula of GFRP-concrete-steel composite beam was exhibited. In general, the calculation method could provide a more accurate theoretical result without complex finite element simulation, and serve for the further study of continuous GFRP-concrete-steel composite beams.

Forecasting Mobile Internet Diffusion Trend Based on Optimized Bass Model

Zhaojie Zhu,Zhenhong Jia,Xizhong Qin 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.9

Experimental and Theoretical Study on the Flexural Performance of GFRP-Concrete-Steel Composite Beams

Zhaojie Tong,Xiaodong Song,Qiao Huang 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.8

A novel GFRP (glass fiber-reinforced polymer)-concrete-steel composite beam bridge was proposed to prolong the service life of bridges. In order to investigate the flexural behavior of the composite beams, four-point bending tests and push-out tests were conducted. First, GFRP-concrete-steel composite beams with different interface types were fabricated and tested. Experimental results indicated the concrete ultimate strain and the ultimate deflection were increased because of the confining effect provided by GFRP plates. The GFRP-concrete interface had no obvious effect on flexural stiffness and flexural capacity. The slip effect of GFRPconcrete- steel beams was similar to that of steel-concrete beams. The failure process of GFRP-concrete-steel beams was different from that of steel-concrete beams due to the effect of the GFRP plate. Then, push-out specimens were tested to investigate the slip effect between GFRP-concrete decks and steel beams. The effect of GFRP plates on the studs was insignificant because of the large stud hole, and a regression formula of load-slip relationship was presented based on the experimental results. Finally, finite element model and theoretical model were employed to analyze the deflection calculation method and the flexural capacity calculation method, respectively.

CuO-doped Ce for catalytic wet peroxide oxidation degradation of quinoline wastewater under wide pH conditions

Zhaojie Jiao,Xianming Zhang,Haifeng Gong,Donglin He,Hong Yin,Yunqi Liu,Xu Gao 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.105 No.-

This study aimed to treat toxic and refractory organic wastewater, and to address the limitations ofFenton method in treating organic wastewater, that the active components are easy to lose and usuallyoperate at the pH value of 2 3. In the present study, CuCe oxide catalyst was produced through citricacid-assisted complexation. Besides, the structural stability and catalytic wet peroxide oxidation (CWPO)performance of the catalyst after 5 times of application were delved into by characterization. The effectsof catalyst dosage and pH on quinoline removal were ascertained, while the reusability of the catalystwas explored. Moreover, the variations of pH, hydroxyl radical concentration and UV–Vis spectra inthe reaction system were analyzed. The possible degradation pathway and the catalytic mechanism werealso discussed. As suggested from the results, the catalyst exhibited high catalytic activity, structural stabilityand pH adaptability; it also had high CWPO performance for quinoline at the pH from 3.8 to 10.5,and the pH value need not be regulated. Under optimal conditions, 98.1% of quinoline and 86.1% of totalorganic carbon (TOC) were removed. In the CWPO process of quinoline, the OH attacked the nitrogen ringand the benzene ring in sequence.

Application of copper sulfate based fenton-like catalyst in degradation of quinoline

Zhaojie Jiao,Haifeng Gong,Ye Peng,Guilin Zhou,Xianming Zhang,Xu Gao,Yunqi Liu 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.5

In the practical application of water treatment, the Fenton reaction usually works at a lower pH. To overcome the above shortcomings, a Fenton-like reaction system with copper sulfate as a catalyst was proposed. In this paper, quinoline was used as the target pollutant and the effects of catalyst dosage, H₂O₂ dosage, reaction temperature, and initial concentration of quinoline and pH on the removal effect were investigated, and the evolution in pH and hydroxyl radical concentration during reaction, as well as the possible catalytic mechanism and degradation pathway were clarified. The results show that under a catalyst dosage of 0.4 g・L<SUP>-1</SUP>, a H₂O₂ dosage of 196 mmol・L<SUP>-1</SUP>, a quinoline concentration of 100 mg・L<SUP>-1</SUP> and a temperature of 75°C, the removal of quinoline and total organic carbon (TOC) reaches 99.5% and 87.2% in 65 min, respectively. Furthermore, the copper sulfate-driven homogeneous Fenton system exhibits a superior adaptability to pH in the range of 3.8 to 8.8. In the degradation of quinoline, ·OH radicals may attack the nitrogen ring and the benzene ring in sequence. The work provides a technical support for the treatment of organic wastewater, and shows promising in practical applications.

Study on Strain Energy Transfer and Efficiency in Spatial Micro-forming of Metal

Zhaojie Chen,Jin Xie,Quanpeng He,Dongsheng Ge,Kuo Lu,Chaolun Feng 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.11 No.2

In spatial micro-fabrication on metallic surface, the mechanical machining consumes material shear deformation energy, while the laser machining energy is greatly converted into material melting heat energy. In production, the micron-scale material-removal machining requires the CNC system to long-time tool path interpolation for high energy-consumption. According to dynamics and kinematics of metallic plastic deformation, a strain energy transfer is proposed to deform micro-topographic shapes by differentiated surface stress. The objective is to realize the precision forming of spatial microstructure surface through the strain energy conversion and conservation. First, the energy transfer and strain variations were modelled in relation to die curvature radius, workpiece thickness, initial microstructure angle and depth. Then, the strain energy consumption was investigated in relation to material properties, die movement, and micro dimensions. Finally, it was applied to industrial cold-pressing. It is shown that the strain energy of a single microstructure formation transfers from centre to outer part. The spatial microstructure forming may change from diversified strain stage to uniform strain state with the highest energy efficiency at a critical strain energy, while the surface roughness remains unchanged. Under the strain energy transfer, the microstructure shape changes with increasing energy consumption to a critical value. The metal compressive strength, die curvature radius and workpiece thickness promotes energy consumption, while descending velocity promotes processing efficiency. By controlling the energy conversion, the spatial microstructure sizes may be fabricated with an error of about 1.0% and the energy consumption of about 10 mm3/J. In industrial production, it contributes high energy efficiency without coolant pollutant in contrast to mechanical machining and laser machining. As a result, the strain energy conversion and conservation may be regarded as an evaluation for an eco-friendly micro-fabrication.

Experimental and analytical study on continuous GFRP concrete decks with steel bars

Zhaojie Tong,Yiyan Chen,Qiao Huang,Xiaodong Song,Bingqing Luo,Xiang Xu 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.6

A hybrid bridge deck is proposed, which includes steel bars, concrete and glass-fiber-reinforced-polymer (GFRP) plates with channel sections. The steel bar in the negative moment region can increase the flexural stiffness, improve the ductility, and reduce the GFRP ratio. Three continuous decks with different steel bar ratios and a simply supported deck were fabricated and tested to study the mechanical performance. The failure mode, deflection, strain distribution, cracks and support reaction were tested and discussed. The steel bar improves the mechanical performance of continuous decks, and a theoretical method is proposed to predict the deformation and the shear capacity. The experimental results show that all specimens failed with shear failure in the positive moment region. The increase of steel bar ratio in the negative moment region can achieve an enhancement in the flexural stiffness and reduce the deflection without increasing GFRP. Moreover, the continuous deck can achieve a yield load, and the negative moment can be carried by GFRP plates after the steel bar yields. Finally, a nonlinear analytical method for the deflection calculation was proposed and verified, with considering the moment redistribution, non-cracked sections and nonlinearity of material. In addition, a simplified calculation method was proposed to predict the shear capacity of GFRP-concrete decks.

A deep learning approach using temporal-spatial data of computational fluid dynamics for fast property prediction of gas-solid fluidized bed

Pengfei Qin,Zhaojie Xia,Li Guo 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.1

To deal with the critical issue of long computational time in practical application of computational fluiddynamics (CFD), this paper presents a new approach of deep learning for voidage prediction (DeepVP) that couplesshort time CFD simulations (limited CFD iterations) with the deep learning method to accelerate the 2D voidage distributionprediction for a gas-solid fluidized bed at steady state. Short time CFD simulations are first performed toobtain a sequence of voidage distribution images containing the temporal-spatial property of a gas-solid fluidized bed ofthe early period. A deep learning model is built to predict the voidage distribution at steady state, which is achieved byimplementing multi-scale convolutional neural networks based on the sequence of voidage images. The case study resultsfor a bubbling bed show that the voidage distribution at steady state for the bubbling bed can be predicted with comparableaccuracy of conventional CFD simulations at about 1/30th computational cost. Moreover, the DeepVP methodexhibits better extrapolation capability than the deep learning approach merely based on CFD condition parameters.

In Situ Growth of MOF-Derived NaCoPO4@Carbon for Asymmetric Supercapacitive and Water Oxidation Electrocatalytic Performance

Peng Guo,Zhaojie Wang,Hongyu Chen,Shaohui Ge,Chen Chen,Haowei Wang,Jinbao Zhang,Minglei Hua,Shuxian Wei,Xiaoqing Lu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.15 No.01

The increasing energy crisis promotes the study on novel electrode materials with high performance for supercapacitive storage and energy conversion. Transition metal phosphates have been reported as a potential candidate due to the unique coordination and corresponding electronic structure. Herein, we adopted a facile method for preparing NaCoPO4@C derived from a metal organic framework (MOF) as a bifunctional electrode. ZIF-67 was synthesized before a refluxing process with Na2HPO4 to form a precursor, which is transformed into the final product via calcination in different atmospheres. Specifically, the resultant NaCoPO4@C exhibits a high specific capacitance of 1178.7 F g -1 at a current density of 1 A g -1 for a supercapacitor. An asymmetric supercapacitor (ASC) assembled with active carbon displays a high capacitance of 163.7 F g -1 at 1 A g -1. In addition, as an oxygen evolution reaction (OER) catalyst, the NaCoPO4@C electrode requires only 299 mV to drive a current density of 10 mA cm -2. These results suggest that the rational design of MOF-derived NaCoPO4@C provides a variety of practical applications in electrochemical energy conversion and storage.

Dietary Saponins of Sea Cucumber Ameliorate Obesity, Hepatic Steatosis, and Glucose Intolerance in High-Fat Diet–Fed Mice

Xiaoqian Hu,Zhaojie Li,Yong Xue,Jingfeng Wang,Yuming Wang 한국식품영양과학회 2012 Journal of medicinal food Vol.15 No.10

Much attention has been focused on food components that may be beneficial in preventing lifestyle-related diseases. In this study, we investigated the effects of saponins of sea cucumber (SSC) on high-fat diet–induced obesity, insulin resistance, and fatty liver in mice. C57/BL6 mice were fed a high-fat diet, containing 0.03% SSC, or 0.1% SSC for 8 weeks. Both doses of SSC exhibited a weight-loss effect and significantly decreased adipose tissue weight, in both visceral and subcutaneous depots. Furthermore, 0.1% SSC treatment dramatically decreased the hepatic triglyceride and total cholesterol accumulation. Mice administrated with 0.1% SSC had significantly decreased serum glucose and insulin levels, lower homeostatic model assessment for insulin resistance index, and area under the blood glucose curve, suggesting that insulin sensitivity is enhanced by dietary SSC. Dietary SSC also prevented adipokine imbalance, by increasing adiponectin production and decreasing tumor necrosis factor alpha level caused by high-fat diet. Overall, these data demonstrate that SSC could improve certain metabolic parameters associated with obesity.