Study of modified Westergaard formula based on dynamic model test on shaking table

Mingming Wang,Yi Yang,Weirong Xiao 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.5

The dynamic model test of dam-reservoir coupling system for a 203m high gravity dam is performed to investigate effects of reservoir water on dynamic responses of dam during earthquake. The hydrodynamic pressure under condition of full reservoir, natural frequencies and acceleration amplification factors along the dam height under conditions of full and empty reservoir are obtained from the test. The results indicate that the reservoir water have a stronger influence on the dynamic responses of dam. The measured natural frequency of the dam model under full reservoir is 21.7% lower than that of empty reservoir, and the acceleration amplification factor at dam crest under full reservoir is 18% larger than that under empty reservoir. Seismic dynamic analysis of the gravity dams with five different heights is performed with the Fluid-Structure Coupling Model (FSCM). The hydrodynamic pressures from Westergaard formula are overestimated in the lower part of the dam body and underestimated in its upper part to compare with those from the FSCM. The underestimation and overestimation are more significance with the increase of the dam height. The position of the maximum hydrodynamic pressure from the FSCM is raised with the increase of dam height. In view of the above, the Westergaard formula is modified with consideration in the influence of the height of dam, the elasticity of dam on the hydrodynamic pressure. The solutions of modified Westergaard formula are quite coincident with the hydrodynamic pressures in the model test and the previous report.

Experimental study on high gravity dam strengthened with reinforcement for seismic resistance on shaking table

Mingming Wang,Jianyun Chen,Shuli Fan,Shaolan Lv 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.4

In order to study the dynamic failure mechanism and aseismic measure for high concrete gravity dam under earthquake, the comparative models experiment on the shaking table was conducted to investigate the dynamic damage response of concrete gravity dam with and without the presence of reinforcement and evaluate the effectiveness of the strengthening measure. A new model concrete was proposed and applied for maintaining similitude with the prototype. A kind of extra fine wires as a substitute for rebar was embedded in four-points bending specimens of the model concrete to make of reinforced model concrete. The simulation of reinforcement concrete of the weak zones of high dam by the reinforced model concrete meets the similitude requirements. A tank filled with water is mounted at the upstream of the dam models to simulate the reservoir. The Peak Ground Acceleration (PGA) that induces the first tensile crack at the head of dam is applied as the basic index for estimating the overload capacity of high concrete dams. For the two model dams with and without strengthening tested, vulnerable parts of them are the necks near the crests. The results also indicate that the reinforcement is beneficial for improving the seismicresistant capacity of the gravity dam.

Experimental and Numerical Comparative Study on Gravity Dam-Reservoir Coupling System

Mingming Wang,Jianyun Chen,Weirong Xiao 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.10

A 203m high gravity dam-reservoir coupling system in earthquake is studied experimentally and numerically in this work. The dynamic model test is performed on a shaking table, and the dynamic process of the coupling system is simulated with two numerical methods. The natural frequency, hydrodynamic pressure on upstream and acceleration amplification factors along the dam height are obtained from the test and the methods. It is found that the results from FSCM agree better with those from test compared with AMM. So the FSCM should be the first choice to analysis the dam-reservoir coupling system interaction under earthquake. The AMM, which is frequently used in the Code for Seismic Design of Hydraulic Structures of many countries, needs to be modified by a factor smaller than 1. The factor varies along the height of the dam according to its shape, reservoir depth and higher modes and so on. Finally, the reduction factors of the AMM along dam height are suggested in this work.

Experimental study on high gravity dam strengthened with reinforcement for seismic resistance on shaking table

Wang, Mingming,Chen, Jianyun,Fan, Shuli,Lv, Shaolan Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.51 No.4

In order to study the dynamic failure mechanism and aseismic measure for high concrete gravity dam under earthquake, the comparative models experiment on the shaking table was conducted to investigate the dynamic damage response of concrete gravity dam with and without the presence of reinforcement and evaluate the effectiveness of the strengthening measure. A new model concrete was proposed and applied for maintaining similitude with the prototype. A kind of extra fine wires as a substitute for rebar was embedded in four-points bending specimens of the model concrete to make of reinforced model concrete. The simulation of reinforcement concrete of the weak zones of high dam by the reinforced model concrete meets the similitude requirements. A tank filled with water is mounted at the upstream of the dam models to simulate the reservoir. The Peak Ground Acceleration (PGA) that induces the first tensile crack at the head of dam is applied as the basic index for estimating the overload capacity of high concrete dams. For the two model dams with and without strengthening tested, vulnerable parts of them are the necks near the crests. The results also indicate that the reinforcement is beneficial for improving the seismic-resistant capacity of the gravity dam.

Capillary Electrochromatography with Liquid Crystal Crown Ether Modified Hybrid Silica Monolith for Analysis of Imidacloprid and Carbendazim in Tomatoes

Mingming Wang,Rui Feng,Jing Shen,Hao Chen,Zhaorui Zeng 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.7

This study describes the ability of capillary electrochromatography (CEC) for the determination of imidacloprid and carbendazim in tomato samples. A novel liquid crystal crown ether modified hybrid silica monolithic column was synthesized, characterized and developed as separation column for the first time. Baseline separation of imidacloprid and carbendazim could be achieved using a mobile phase containing 90% (v/v) 20 mmol/L phosphate buffer (pH 7.0) and 10% (v/v) acetonitrile. The matrix matched calibration curves were linear with correlation coefficient r2 > 0.9998 in the range of 0.20-10.00 mg/L. The limits of detection for imidacloprid and carbendazim were 0.061 and 0.15 mg/kg, respectively, which were below the maximum residue limits established by the European Union as well as Codex Alimentarius. Average recoveries for imidacloprid and carbendazim varied from 101.6-108.0% with relative standard deviations lower than 6.3%. This method was applied to the analysis of tomatoes collected from local markets.

Capillary Electrochromatography with Liquid Crystal Crown Ether Modified Hybrid Silica Monolith for Analysis of Imidacloprid and Carbendazim in Tomatoes

Wang, Mingming,Feng, Rui,Shen, Jing,Chen, Hao,Zeng, Zhaorui Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.7

This study describes the ability of capillary electrochromatography (CEC) for the determination of imidacloprid and carbendazim in tomato samples. A novel liquid crystal crown ether modified hybrid silica monolithic column was synthesized, characterized and developed as separation column for the first time. Baseline separation of imidacloprid and carbendazim could be achieved using a mobile phase containing 90% (v/v) 20 mmol/L phosphate buffer (pH 7.0) and 10% (v/v) acetonitrile. The matrix matched calibration curves were linear with correlation coefficient $r^2$ > 0.9998 in the range of 0.20-10.00 mg/L. The limits of detection for imidacloprid and carbendazim were 0.061 and 0.15 mg/kg, respectively, which were below the maximum residue limits established by the European Union as well as Codex Alimentarius. Average recoveries for imidacloprid and carbendazim varied from 101.6-108.0% with relative standard deviations lower than 6.3%. This method was applied to the analysis of tomatoes collected from local markets.

Experimental Study on Mechanical Properties of Continuous Welding Stainless Steel Roof System under Temperature Effect

Mingming Wang,Tong Ou,Zhiyong Xin,Dayang Wang,Yongshan Zhang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

Stainless steel is used as a new generation of long-span metal roof systems with continuous welding technology, which exhibits many unknown behaviors during temperature action. This study focuses on the temperature effect of a continuous welded stainless steel roof (CWSSR) system and analyzes the stress distribution of plate rib (PR), plate surface (PS), and support (SU), and the horizontal and vertical displacement. Furthermore, the thermal action of the CWSSR system is comprehensively analyzed considering different loading rates, constant temperature time, and the cycle number. Research results show that the stress concentration and thermal expansion of the CWSSR system are obvious, and fatigue damage occurs under long-term temperature action. The responses of the CWSSR system are greatly influenced by the loading rate and the cycle number but are less influenced by the constant temperature time. Loading rate and the cycle number mainly affect the plate surface stress and vertical displacement. The plate surface stress and vertical displacement peak increased by 34.6% and 29.6% with the loading rate, and changed by 32.4% and 42.5% with the cycle number. Cyclic loading reduces support tensile capacity by 4.4%. The research results can provide reference for the design and application of temperature field resistance of the CWSSR system.

Wind resistance performance of a continuous welding stainless steel roof under static ultimate wind loading with testing and simulation methods

DaYang Wang,Zhendong Zhao,Tong Ou,Zhiyong Xin,Mingming Wang,Yongshan Zhang 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.1

Ultrapure ferritic stainless steel provides a new generation of long-span metal roof systems with continuous welding technology, which exhibits many unknown behaviors during wind excitation. This study focuses on the wind-resistant capacity of a new continuous welding stainless steel roof (CWSSR) system. Full-scale testing on the welding joints and the CWSSR system is performed under uniaxial tension and static ultimate wind uplift loadings, respectively. A finite element model is developed with mesh refinement optimization and is further validated with the testing results, which provides a reliable way of investigating the parameter effect on the wind-induced structural responses, namely, the width and thickness of the roof sheeting and welding height. Research results show that the CWSSR system has predominant wind-resistant performance and can bear an ultimate wind uplift loading of 10.4 kPa without observable failures. The welding joints achieve equivalent mechanical behaviors as those of base material is produced with the current of 65 A. Independent structural responses can be found for the roof sheeting of the CWSSR system, and the maximum displacement appears at the middle of the roof sheeting, while the maximum stress appears at the connection supports between the roof sheeting with a significant stress concentration effect. The responses of the CWSSR system are greatly influenced by the width and thickness of the roof sheeting but are less influenced by the welding height. Ultrapure ferritic stainless steel provides a new generation of long-span metal roof systems with continuous welding technology, which exhibits many unknown behaviors during wind excitation. This study focuses on the wind-resistant capacity of a new continuous welding stainless steel roof (CWSSR) system. Full-scale testing on the welding joints and the CWSSR system is performed under uniaxial tension and static ultimate wind uplift loadings, respectively. A finite element model is developed with mesh refinement optimization and is further validated with the testing results, which provides a reliable way of investigating the parameter effect on the wind-induced structural responses, namely, the width and thickness of the roof sheeting and welding height. Research results show that the CWSSR system has predominant wind-resistant performance and can bear an ultimate wind uplift loading of 10.4 kPa without observable failures. The welding joints achieve equivalent mechanical behaviors as those of base material is produced with the current of 65 A. Independent structural responses can be found for the roof sheeting of the CWSSR system, and the maximum displacement appears at the middle of the roof sheeting, while the maximum stress appears at the connection supports between the roof sheeting with a significant stress concentration effect. The responses of the CWSSR system are greatly influenced by the width and thickness of the roof sheeting but are less influenced by the welding height

FLOURY ENDOSPERM12 Encoding Alanine Aminotransferase 1 Regulates Carbon and Nitrogen Metabolism in Rice

Mingsheng Zhong,Xi Liu,Feng Liu,Yulong Ren,Yunlong Wang,Jianping Zhu,Xuan Teng,Erchao Duan,Fan Wang,Huan Zhang,Mingming Wu,Yuanyuan Hao,Xiaopin Zhu,Ruonan Jing,Xiuping Guo,Ling Jiang,Yihua Wang,Jianmi 한국식물학회 2019 Journal of Plant Biology Vol.62 No.1

Starch is a major storage substance in cerealgrains, and starch biosynthesis is a complex process. In orderto elucidate regulation of the starch biosynthesis pathway, wescreened a series of rice (Oryza sativa L.) endospermmutants. In this study, we identified a floury white-coreendosperm mutant named floury endosperm12 (flo12). Theflo12 mutant exhibited loosely packed starch granules and alower thousand kernel weight compared to wild type. Semithinsections revealed that compound starch grains (SG) inflo12 interior endosperm cells were developed abnormally. Furthermore, amylose content was decreased, while totalprotein content was significantly increased in flo12 grains. Map-based cloning showed that FLO12 encodes rice alanineaminotransferase 1 (OsAlaAT1). OsAlaAT1 is highly expressedin developing endosperm. Subcellular localization showedthat OsAlaAT1 is localized in the cytosol. Moreover, theexpression of most starch synthesis-related genes wasdecreased, while most of the storage protein coding geneshad elevated expression levels in the flo12 mutant. Inaddition, overexpression of the OsAlaAT1 gene increasedgrain weight. In brief, we demonstrated that OsAlaAT1regulates carbon and nitrogen metabolism, which provides anew insight for the improvement of rice quality and yield.

AN ECONOMICAL VELOCITY PLANNING ALGORITHM FOR INTELLIGENT CONNECTED EVS BASED ON REAL-TIME TRAFFIC INFORMATION

Mingming Qiu,Lei Wang,Xiaoyu Mu,Wei Yu,Kang Huang 한국자동차공학회 2024 International journal of automotive technology Vol.25 No.2

The energy effi ciency of intelligent networked connected electric vehicle (EV) is directly related to its velocity. Aiming atthe infl uence of real-time traffi c fl ow information on road speed interval, a two-layer speed planning method is proposed. The upper layer extracts the road speed interval according to the traffi c fl ow information, and based on cellular automata andconfi dence interval theory, traffi c information rules are introduced, and a road speed interval extraction method consideringtraffi c density information is established. The lower layer is used to obtain energy-optimal cruising velocity profi le. Takingthe road speed interval as the variable boundary constraint, a dynamic programming algorithm that changes the state quantityboundary in real time is designed, which realizes the effi cient acquisition of the energy-optimized velocity trajectory. To verify the eff ectiveness of proposed approach, the simulation model is formulated based on using collected real traffi cinformation. The simulation results demonstrate that, compared with the conventional constant speed cruising strategy anddynamic programming (DP) strategy based on road speed interval, the strategy proposed in this study not only improvesenergy effi ciency and reduces computing time signifi cantly, but also can predict the traffi c conditions ahead to avoid largefl uctuations in velocity. Besides, the biggest signifi cance of this study is the designed economic velocity planning algorithmbased on real-time traffi c density information improves the adaptability of intelligent networked connected EV controlstrategy to actual traffi c conditions, and extends the optimization dimension of eco-driving.