bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of the specimen form on high cycle fatigue properties of 7050-T7451 and 2524-T3 aluminum alloys
Authors: Tong Dihua , He Yuhuai , Hu Benrun , Chen Bo , Zhao Yanguang
Published: March 2020

High cycle fatigue properties of 7050-T7451 and 2524-T3 aluminum alloys at three stress ratios R=-1, 0.06, and 0.5 were experimentally studied, in which the axial stress control method was used to measure the funnel-shaped and iso-section specimens, with a MTS electro-hydraulic test system. Stress-life data were obtained and equivalant stress-life curves were plotted based on the equivalent stress model. Results showed that as for 7050-T7451 and 2524-T3 aluminum alloys, stress-life curves obtained with two kinds of specimens basically agreed, and effects of the specimen form on high cycle fatigue properties of these two aluminum alloys can be neglected.
Micro-X-Ray Diffractometer Focused by Polycapillary Optics and Its Applications for Materials
Authors: Jiang Qili , Shuai Qilin , Liu Jun , Cheng Lin
Published: March 2020

The analysis of small samples and micro areas of large samples are significant in material, environment and geology fields. This work reports the study of a micro-X-ray diffractometer developed by our laboratory and its applications for not only micro-X-ray diffraction (μ-XRD) analysis but also micro energy dispersive X-ray fluorescence (μ-EDXRF) analysis. The accomplishment of the two analysis methods in one instrument makes it possible to characterize micro materials in situ by a very efficient way. In order to demonstrate the feasibility of this diffractometer, the samples difficult to be measured by the conventional diffractometer were studied. Firstly, a cooper wire with a diameter of 140 μm was analysed as a micro sample. Then two different points of a TiN film were analysed to discuss their phase transitions in micro areas. Moreover, the phase distribution of a two-dimensional area on an iPhone mainboard was scanned. The phase mapping was acquired by data processing. These researches highlight the abilities of this diffractometer in the applications on micro material characterizations. As a result, this diffractometer can adapt to the analyses of elemental composition, mineralogical composition and their distributions in the micro materials. It can also provide useful reference information for the micro phase transitions. Therefore, it can be concluded that this micro-X-ray diffractometer has potential prospect in the micro material analysis and any other related fields.
Preparation and properties of solid waste based lightweight plastering gypsum
Authors: Tian Xiaohua , Liu Dongji , Zhao Fengqing
Published: March 2020

The lightweight plastering gypsum with excellent heat preservation performance was prepared from β-hemihydrate gypsum obtained by calcining desulfurization gypsum, the polyurethane foam waste modified with water glass, and a composite auxiliary agent composed of ground steel slag and granulated blast-furnace slag. The density of the product is 762.3 kg/m3, the initial setting time is 150 min, the final setting time is 205 min, the flexural strength is 3.1 MPa, the compressive strength is 6.8 MPa, and the thermal conductivity is 0.098 W/(m⋅K).
Study on Mechanical Behaviors and Electrolyte Uptake of PVDF/PES/TiO2 Composite Fiber Separators
Authors: Cheng Kai , Chen Xin , Liu Shuai , Cao Qingyuan , Yu Weiwei , Cui Weiwei
Published: March 2020

In this paper, polyvinylidene fluoride (PVDF)/polyether sulfone (PES) spinning solution with different TiO2 content was obtained by in-situ generation. The prepared spinning liquid was fabricated into PVDF/PES/TiO2 composite membranes via electrospinning. The scanning electron microscopy (SEM), differential scanning calorimetry (DSC), mechanical properties, electrolyte uptake were conducted to test the performance of the obtained separators. The effect of TiO2 contents on the properties of PVDF/PES separators was discussed. The experimental results show that the doping of nano-TiO2 particles will enhance the performance of the separators. DSC test and electrolyte uptakes showed that the enthalpy of the polymer decreased and the electrolyte uptake increased with TiO2 contents. When the separators contents 2 wt% TiO2, the enthalpy changes reach the maximum (28.259 J/g), and the crystallinity is measured to 26.99%. With the TiO2 addition increases, the tensile strength of the membrane also showed the tendency of increasing first and then decreasing. At 6 wt%TiO2, the tensile strength of the membrane was better, reaching 5.606 N/mm2, and the toughness was the best. It shows that the addition of TiO2 helps to enhance its tensile strength as well as toughness When the TiO2 content is 6 wt%, the overall performance of the membrane is the best.
Design and Performance Test of an HTS Magnet for 1 MW HTS DC Induction Heater
Authors: Hu Lei , Dai Shaotao , Yan Xufeng , Ma Tao , Zhang Teng , Wang Bangzhu
Published: March 2020

Compared with a small magnet, the magnet for IMW HTS DC induction heater is larger, and the radius reaches up to 2200mm, which will bring great difficulties to the winding of superconducting magnets. To ensure that the design and fabrication of the large-diameter HTS DC magnet can be a one-shot success, some smaller HTS magnets, including three 200 mm diameter magnets and two 600 mm diameter magnets, have been designed and fabricated. The structure of these magnets is similar to the final 2200 mm diameter prototype magnet, which is wound in a spiral way. Performance test results of all the superconducting magnets have proved that the winding process and curing process of the magnet is feasible and can be used to make large-diameter magnets formally.
Nuclear Power Plant Operator Auxiliary Robot System
Authors: Fang Xiang , Wang Limin
Published: March 2020

The potential problems on nuclear power plant when being operated by nuclear power plant (NPP) operators are discussed in the paper. The solution related to artificial intelligence (AI) is suggested. When using auxiliary robot system to support NPP operators to operate NPP, the relevant technologies and solutions are analyzed. The application of auxiliary robot system can be developed to other industries operation on operators support.
Study on chemical kinetic mechanisms of Polyoxymethylene Dimethyl Ethers (PODEn)
Authors: Zhao Yuwei , Li Ning , Xie Yijing , Cheng Yuemeng , Wang Xiaochen
Published: March 2020

Based on the latest detailed mechanism of Dimethoxymethane (DMM), a new chemical kinetic mechanism model of Polyoxymethylene Dimethyl Ethers (PODEn) with high degree of polymerization was preliminarily developed by extending reaction classes of DMM to PODE3 with the same rate coefficient criterion. Compared with the existing PODEn model and experimental data, it was observed that the model of He could forecast the experimental data of PODE3 accurately, but the prediction ability of the underlying DMM mechanism was poor. The model developed in this paper could forecast DMM experimental data accurately but could not forecast the experimental data of PODE3 accurately. The same reaction classes of PODEn with different degree of polymerization did not have the same rate coefficient criterion.
Research on anti-explosion performance of a new composite structure
Authors: Xu Hao , Qiu Xiaoqing , Wang Gang , Zhang Xiaofeng
Published: March 2020

A rigid-flex composite composite structure is proposed and its impact resistance under blast load impact is studied. Using the finite element software Abaqus/Explicit, the three-dimensional Hashin failure criterion was established by writing the VUMAT subroutine, and the three-dimensional solid finite element model of the composite laminate was established by using the Cohesive interface unit as the bonding layer. The reliability is verified by comparing the simulation results of the finite element model with the results of the existing literature. Through simulation analysis, it is found that after adding the flexible layer, the energy absorption capacity of the structure is improved, the resistance to deformation is slightly reduced, the design requirements are met, and the expected effect is achieved.
Effect of loading frequency on corrosion fatigue crack growth rate of 7N01 aluminum alloy
Authors: Yu Yangyang , Sun Weiguang , Tong Dihua
Published: March 2020

The fatigue damage of engineering structures is mostly caused by cyclic stress and external environmental factors. Therefore, the study of corrosion fatigue crack propagation is of great significance to the safety and durability of structures. The effects of different loading frequencies (10Hz, 1Hz and 0.1Hz) on fatigue crack growth rate of 7N01 aluminum alloy in humid air were studied by using load control method. The results show that the corrosion fatigue crack growth rate is basically the same at 10Hz and 1Hz, When the loading frequency decreases to 0.1Hz, the corrosion fatigue crack growth rate is slightly higher than 10Hz and 1Hz.
Preparation of Silicon Carbide hollow fiber Membrane in Low Temperature by Precursor Pyrolysis
Authors: Xu Man , Guan Mengke , Wang Shulin , Wu Mengyu
Published: March 2020

The silicon carbide (SiC) powder is covered with polycarbosilane (PCS), N-Methyl pyrrolidone (NMP) is a solvent, polyethersulfone (PES) is a bonding aid, using phase-phase and solid-phase sintering process combined with a step-by-step molding to prepare a symmetrical structure of silicon carbide hollow fibers, and determine the membrane’s perforation and purification and purity of the water distribution and the circumference of the membrane. The results show that the SiC membrane tube is a finger-hole structure layer-spongy structure layer-finger-hole structure structure, the optimal sintering temperature is at 1200 °C, the size of the prepared ceramic membrane aperture is concentrated in about 0.9 μm, and the pure water flux is 2.832m3 / (m2⋅h).
Separation of waste cotton-polyester blended fabric
Authors: Li Zhi
Published: March 2020

The separation of waste textiles could reduce the pollution and pressure of the environment. Through this article, as the procedures of added glycol (EG) and catalyst in reaction system. After depolymerize the polyester fibre(PET) of the waste cotton-polyester blended fabric to alcoholysis as bis-hydroxyethyl terephthalate (BHET), and then separate it with solid cotton and liquid BHET through the solid - liquid separation device.
Fracture Failure Analysis of Flameproof Enclosure of Hydraulic Pump Regulator
Authors: Wang Yufei , Wang Yu
Published: March 2020

A flameproof enclosure of hydraulic pump regulator has undergone a durable vibration fatigue test. Lugs have been found dropped during the test before the expected life. Failure analysis has been carried out by means of macro and micro observation, energy disperse spectrum analysis, metallographic examination and hardness test. The reason of the failure is the fatigue resistance of this flameproof enclosure is not enough to endure the test. According to suggestions, a new structure flameproof enclosure has been improved to instead of the flanging lugs. The improved new one has passed the vibration test successfully.
Study on the interface of Al/Mg bimetal by static casting
Authors: Yu Yingshui , Yu Xincheng , Li Bo , Yao Chenglong
Published: March 2020

In this study, fine aluminum cladding AZ91 magnesium alloy composite ingot was prepared under static casting. The microstructure and phase constituents of the interface were investigated by optical microscopy. The result shows that the interface from the Al matrix side can be divided into three parts. A diffusion layer made up by β-Al3Mg2, Mg-Al mtermetallic compound layer which is made up by γ-Mg17Al12 and a eutectic structure layer made up by α-Mg and γ-Mg17Al12. The element distribution is investigated by methods of electron probe microanalysis (EPMA). The component ratio of Al to Mg decreases in the whole interface. But the descent becomes very slow in the α-Mg and γ-Mg17Al12 eutectic structure layer. The Vickers hardness in the matrix and interface were also measured. The value of microhardness decrease with the phase changing in the whole interface from 120 HV to 275HV, but it’s still much higher than the Al matrix or AZ91 matrix as well.
Mixing Characteristics of Polymer Melt in Triple Screw Extruders with Combined Screws using Finite Element Method
Authors: Xin Yaoyu , Zhu Xiangzhe , Wang Tianshu
Published: March 2020

The triple screw extruder is a new equipment of polymer processing. A three-dimensional modelling of a triple screw extruder with combined screws of convey and mixing elements is adopted to investigated the flow and mixing characteristics by using Polyflow software based on finite element method. The axial velocity and pressure distributions in the special central region of the triple screw extruder are specially analyzed. Some mixing evaluated parameters, such as area stretching rate, the probability of mixing index, segregation scale and residence time distribution in different boundary conditions are calculated based on particle tracing method. Moreover, the effects of screw clearance and inlet flow rate of combined screws on the mixing characteristics of polymer melt are discussed. The results show that the increase of the screw clearance can increase the residence time and improve the mixing efficiency of extruder. With the decrease of inlet flow, the distributive mixing efficiency in the triple screw extruder increase gradually.
In-situ growth of β-SiC nanofibers from polymer precursors
Authors: Xu Man , Peng Yongzhi , Yang Kun
Published: March 2020

Silicon powder and different organic polymers were used to in-situ growth of SiC nano fibers on porous SiC ceramic in the current study. SEM analysis showed the most abundant nano fibers were obtained by milling silicon powder for 12 hours, and the highest aspect ratio of nano fibers was obtained by milling for 24 hours. starch, guar gum and collagen were used separately as binding materials for preparing cellulose-silicon powder precursors. The best growth of nano fibers was obtained with addition of collagen. The growth mechanism of nano fibers was proved to be vapor-liquid-solid (VLS). XRD analysis indicated the main crystalline phase is β-SiC after 1400°C pyrolysis.
Experimental study on resistance stability and durability of road active deicing conductive Ethylene Propylene Diene Monomer rubber composites
Authors: Wei Haibin , Ma Zipeng , Han Shuanye
Published: March 2020

Active deicing is the main way to deal with snow and ice disaster now. In order to realize the purpose of active heating deicing, a kind of Ethylene Propylene Diene Monomer (EPDM) multilayer composite with conductivity is proposed in this paper. The resistance stability of conductive EPDM rubber composite is measured after pressure sensitivity, freezing-thawing cycle and high-temperature tests. The results show that the conductive EPDM rubber composite developed in this paper has good compression stability and good resistance durability after low temperature freezing-thawing cycle and high-temperature test.
The Method of Road Traffic Risk Assessment
Authors: Zhu Chao
Published: March 2020

In this paper, a method of assessing the level of road traffic risk sources is proposed. First, based on the key elements involved in road traffic safety, all risk sources are divided into two groups, namely the infrastructure-related risk source and the equipment-related risk source. Then, the risk source is further divided into four grades according to the damage that they could cause. Lastly, a LEC method is introduced to evaluate the influence of risk sources quantitatively.
Research and implementation of tunnel construction schedule management system based on Unity3D
Authors: Zou Yan , Wang Shilin , Shi Wenhao
Published: March 2020

In view of the slow progress of tunnel engineering construction in China due to the influence of terrain geology and climate, a tunnel construction progress management system based on virtual reality simulation technology is developed. The article uses Revit for high-quality model, Unity3D is a three-dimensional virtual reality engine to develop a construction progress management system for construction progress recording and early warning. The results show that the tunnel construction progress management system developed based on Unity3D can alleviate the lag of construction progress, achieve safe and controllable construction site.
Analysis of construction technology and technical advantages of a kind of environmental homogeneous plastic pile
Authors: Ji Feng , Qiu Chengchun , Yao Da , Weng Jiaxing , Xu Guizhong
Published: March 2020

Environmental Homogeneous Plastic (EHP) Pile is an improved cement-soil mixing pile with controllable and adjustable physical and mechanical properties. It is formed by completely replacing and filling while forming holes, so as to solve the disadvantages of traditional cement-soil mixing piles, such as insufficient mixing, uneven pile body and low pile strength. The construction technology of EHP piles was introduced and field standard penetration tests were carried out on EHP piles with different cement contents. It is found that the number of blows required to penetrate a 30cm depth increases with the increase of cement content at the same pile depth. At the same cement content, the number of blows of the EHP pile is greater than that of the traditional cement-soil mixing pile. The change in the number of blows along the pile depth of the EHP pile is also much smaller. Finally, the technical advantages of EHP piles are summarized: uniform and integrated pile body, quality-assured admixture, controllable pile material, and environmental protection.
Numerical study on the sedimentation at intake of the new water supply project in the LaoYeMiao area of Poyang lake
Authors: Wang Zhichao , Niu Jiao , Huang Zhiwen
Published: March 2020

The water intake of a new water supply project of Lushan City is located on the opposite side of the LaoYeMiao in Poyang Lake. Dredging is required between the shore and the deep trough to allow water to be introduced into the intake during low water season. Based on the intake dredging project, this study established a numerical model of water and sediment transport of the research area. The model is verified in terms of water level, flow velocity, erosion-deposition rate using hydrological and topographical data. The characteristics of water flow and erosion-deposition, before and after the implementation of different dredging schemes, are studied and the influence by dredging project are analyzed from the hydrodynamics perspective. The simulation results show that the water level and flow velocity change before and after the dredging project is less than 0.002m and 0.1m/s. The dredging area before and after the project shows deposition, and the average deposition rate changed by 0.01m/year. research shows that the dredging project only affects the erosion and deposition of the dredging area. The adjustment of the dredging scheme will not have a significant impact on the deposition rate and distribution of the area. The research results can provide a scientific basis for the argumentation and optimization of the water intake dredging scheme.
Study on effective protective area of ceramic composite target
Authors: Su Chuanchen , Chen Bin
Published: March 2020

In order to study the difference of ballistic performance in different area of ceramic composite spaced targets, penetration experiment of two targets is conducted. Based on the experiment results, simulation method is used with the dynamic analysis software ANSYS/LS-DYNA, by which the process and mechanism of armour protection is discussed, as well as the effect of unit shape on ballistic performance of targets. It is revealed that the segmentation degree of ceramic cone accounts for the difference in ballistic performance. Besides, the critical points of effective protection is calculated, and the effective protective area of both targets is measured.
Numerical analysis of XCC pile group effect and bearing capacity of piled raft foundation
Authors: Wu Qi , Xu Lai
Published: March 2020

A series of three-dimensional numerical models were established based on the field test to study the interaction of pile-raft-soil system in X-section cast-in-place concrete (XCC) piled raft foundation. The analysis of influence factors of XCC pile group effect was carried out by introducing the interaction factor of piles, and the bearing capacity of XCC piled raft foundation was discussed through comparison with XCC elevated pile foundation and single XCC pile foundation. The computed results shown that the pile location, pile number, pile and soil modulus ratio and pile spacing had a certain effect on the XCC pile group effect. The raft had a negative effect on the bearing capacity of XCC piled raft foundation compared with the foundation without rafts. The ultimate bearing capacity of XCC piled raft foundation was larger than that of XCC elevated pile foundation because the raft and pile of XCC piled raft foundation could provide stronger constraints on the soil between piles and strengthened it.
Dynamic Response of Piles under Wave Loading Based on Comsol Multiphysics
Authors: Liu Yafeng , Jiang Pengming , Wang Yonglu
Published: March 2020

In order to simulate the action of waves on Submarine Structures, COMSOL Multiphysics Finite Element Analysis Software was used. By solving Helmholtz equation in frequency domain of given frequency and introducing artificially applied background acoustics field, considering incidence and penetration of acoustics pressure at the junction of seabed and water surface, a total acoustics field is established. Porous media was characterized by Biot’s consolidation theory to compute the displacement field and acoustics pressure fluctuation in porous media propagating porous elastic waves, considering the viscous loss of the model,so the deformation of Solid Matrix can be described. Finally, a numerical model of wave-pile-seabed was established by coupling the pressure acoustic physical field with the physical field of porous media. The influence of different wave frequencies and wave incidence angles on the displacement of piles and the influence of different wave incidence angles on the stress of piles were analyzed. Finally, the liquefaction of soil around piles was studied.
Research progress of anti-penetration yaw technology for concrete protective structures
Authors: Zhang Wei , Di Baojun , Song Dianyi
Published: March 2020

Concrete protective structure is an important part of national defense engineering. It is of great significance to study its development status and penetration mechanism. This article summarizes the recent research status of concrete protection yaw technology, and summarizes the existing yaw technology by distinguishing materials and structural asymmetry. The anti-penetration and yaw mechanism of the protective structure is summarized: The first is to analyze the effects of warhead shape and material, the incident state of the projectile, the configuration of the reinforcement and the aggregate parameters on the resistance to the penetration and yaw. The second is angle of attack effect and contact theory; the third is to analyze the role of numerical simulation in the research of yaw technology; and put forward suggestions for future research work.
Comparison of soil classification from CPTU method and lab method in railway engineering
Authors: Wang Junpeng , Wang Bingkang
Published: March 2020

This article gives a engineering case of CPTU method and laboratory method in soil classification in railway subgrade engineering. In China, soil classification in railway subgrade engineering is often obtained through the traditional laboratory test. With in-situ tests developed in China, CPTU test is used widely in stratigraphy for soft deposit in railway subgrade survey and the National Railway Administration code based on CPTU test is also established. A study is made with a engineering case of subgrade. Two methods are applied in identifying soil strata respectively and differences of them are also discussed.
Yushulin Oilfield CO2- Comparison of minimum miscibility pressure test results for crude oil system
Authors: Liu Li , Pi Yanfu , Liu Yingjie , Ma Yingxue , Qiang Xiaojun , Liu Jinxin , Zhang Zhenxing
Published: March 2020

Miscible displacement of carbon dioxide in low permeability sandstone reservoirs can greatly improve oil recovery. The minimum miscible pressure is the starting point of miscible flooding. Its determination is very important for oilfield development. In this paper, the error analysis of the results measured by empirical formulas is carried out by the internationally accepted slim tube experiment method. Research results show that the minimum miscibility pressure obtained by slender tube displacement experiment is 22.12 MPa. The maximum, minimum and average miscibility pressures predicted by empirical formula method are 32.33 MPa, 7.85 MPa and 19.76 MPa, respectively. The relative error of the average minimum miscibility pressure predicted by all empirical formulas is 10.67%. The least relative error is the Yelling and Metcalfe correlation method, the relative error is 8.82%.
Energy-Saving Transformation Design of Existing Residential Buildings in Qinba Mountainous Areas
Authors: Zhou Shihang , Wang Qing , Zhu Yiyun
Published: March 2020

Through investigation, it is found that some existing buildings in Qinba Mountain have high energy consumption and poor indoor thermal comfort. The cost of demolishing and rebuilding is relatively high. Therefore, it is an important issue for the current urban residential development to study suitable local reconstruction strategies. Taking an old community in Hanzhong City of Qinba Mountain as an example, the field test of indoor and outdoor thermal environment in winter and summer was carried out for one house. The current situation of indoor thermal environment in Qinba mountain city buildings in winter and summer was analyzed. The environmental conditions are not ideal. This article uses DesignBuilder software to carry on the comprehensive transformation design to the wall of this existing building, the roof, the outer window and so on, and carries on the simulation analysis to its indoor thermal environment, the result shows that the enclosing structure has a greater influence on the thermal environment of the local building; the transformation model was obtained: 30mm EPS insulation layer was added to the wall, 50mm EPS insulation layer was installed on the roof, and plastic window (6+13A+6) was used as the outer window. After the renovation, the indoor temperature was increased by 11%-21%. This result can provide a certain theoretical reference for the energy-saving reconstruction of the existing residential houses in the Qinba Mountains.
Investigation on axial compressive stress-strain relationship of expanded fiber reinforced concrete
Authors: Wang Limin , Gao Peiwei , Tian Minghao , Tian Yilang , Zhong Jianjun
Published: March 2020

In order to improve the crack resistance and durability of concrete, basalt fiber and calcium-magnesium expansion agent was used to test the stress-strain relationship and full curve of axial expansion of fiber-expanded concrete with different factors through three-factor three-level orthogonal test. The study of the influence of structural parameters on the constitutive equation of fiber-expanded concrete with different contents and the relationship between the amount of fibers and expansion agents and the parameters of the constitutive equation of the axial compression stress-strain curve were determined. The results have shown that basalt fibers can significantly improve the toughness and ductility of concrete after failure, and the expansion agents can increase the ductility of concrete. When the fiber content is 1%, the expansion agent content is 7%, and the water-binder ratio is 0.42, the mechanical properties are the best. The constitutive parameter β of the rising section of the axial compressive stress-strain curve is 3.1 and the constitutive parameter β of the falling section is 0.6.
Research Progress on Internal Shear Connection of Double Steel Plate-concrete Composite Shear Wall
Authors: Zhang Zhuangnan , Shi Rui , Cheng Daye
Published: March 2020

A comprehensive analysis of three types internal shear connection of double steel plate-concrete composite shear walls is carried out. There are internally welded shear connectors, tension restraints shear connectors, and cavity-type. The analysis shows that these three types of shear connection forms have significant effects on the improvement of the seismic performance of shear walls, and can give full use of the properties of steel and concrete. Compared with the traditional shear wall, the steel plate concrete shear wall has been greatly improved and has a high level of industrialization. Aiming at these three types of shear connection forms, their deficiencies and future development directions were clarified.
Study on bending properties of recombinant bamboo and glued bamboo
Authors: Yang Zhipeng , Hu Yifan , Qiu Xiaoqing
Published: March 2020

Reorganized bamboo is a kind of bamboo composite material that reorganizes and reinforces bamboo. The glued bamboo is a composite material of bamboo fiber and phenolic glue with specific fiber arrangement and special processing. In this paper, the three-point bending test of reconstituted bamboo and glued bamboo was carried out, and the load-span deflection curve was obtained. The ultimate bearing capacity, flexural strength and elastic modulus were studied. The results show that the flexural strength of the recombinant bamboo is greater than that of the glued bamboo. However, the ductility of glued bamboo is better than that of recombinant bamboo.
Optimization design of basalt fiber reinforced stabilizer using response surface methodology
Authors: Liu Jinming , Ou Zhongwen , Mei Yong , Xing Yan , Xie Wei
Published: March 2020

This paper addresses the strength development of a basalt fiber reinforcedcement-based soil stabilizer.In order to develop eco-friendly high performance stabilizer, cementitious capillary crystalline waterproof material is used as alternative to partially replacesulphate aluminum cement.Driven by the purpose of achieving a high strengthperformancewithout impairing other desirable properties, calcium sulfate, basalt fiber and hydrophilicalumina suspension are selected as additives. By adopting the Response Surface Method,the combinedeffects of the three additives on the unconfined compressive strength of the stabilized soil are analyzed. The basalt fiber can constrain the growth of micro cracks and pores, and thus control their coalescence. Incorporating basalt fiber in combination with calcium sulfate and alumina suspension can not only increasethe strength and hardening of stabilized soil, but also improve other properties, especially for enhancingthe ability of cementing, andfor raising the fracture roughness, and therefore improve the durability.The microstructure changes as a consequence of stabilization process arecharacterized by the scanning electron microscope to analyze the origination of the high strength and durability of stabilized soil.The difference of mineral components between the untreated and stabilized soil samples is identified by the X-ray diffraction analysis.
Study on fluidity and strength of dredged sludge under water curing condition
Authors: Cao Yupeng , Zhang Jing , Zhang Shuai , Xu Guizhong , Xu Jianwen
Published: March 2020

Dredged sludge can be used in engineering by treating with flowing solidification method underwater, but the flow solidification characteristics of dredged sludge in underwater curing condition are not clear. The influence of initial water content, cement content and curing age on the fluidity and strength of solidified sludge was discussed through laboratory tests. The results show that the strength of solidified sludge under water curing situation increase linearly with cement content, decreases linearly with the initial water content, and increases logarithmically with the curing age. The relationship of unconfined compressive strength with liquid limit and initial water content for dredged sludge at 28 days curing age was proposed and verified, which provides an important basis for field application and strength prediction of flow solidification treatment.
Experimental behaviour of prefabricated pile-cap foundation under seismic loading
Authors: Gao Xian , Liao Feiyu , Zhou Jian , Zhang Kai , Huang Yuqi , Zhang Na
Published: March 2020

Precast building has attracted more and more interest of both researchers and engineers due to fast constructional speed and lower labour cost. In the past, the precast structure was generally used in the superstructure, such as load bearing frame, however, it is seldom applied in the substructure such as foundation. The paper thus proposed a type of pile-cap connection to fabricate the foundation of a substation. A series of tests on the prefabricated pile-cap connection using these connections were carried out under seismic loading. The failure mode and lateral load versus lateral displacement response of the tested specimens were experimentally investigated. The seismic behaviour of the precast foundation was compared with the behaviour of the corresponding cast-in-place foundation.
The Reservoir Characteristics Study on Yingshan Formation of the Ancient City-Lowuplift in Tarim Basin
Authors: Zhang Xiangjuan
Published: March 2020

The oil and gas exploration has been broken through in ordovician-Yingshan formation of the lower Paleozoic in ancient city-low uplift, in Tarim Basin. The preliminary study found that the rich oil and gas resources are mainly in karst cave of the dolomite reservoir. It is revealed that the exploration potential of the carbonate reservoir in Yingshan formation of the ordovician. So, the systematic evaluation and study on the carbonate reservoir for Yingshan formation of the Ordovician in ancient city-low uplift have been done. Based on the analysis of drilling, logging, well logging and testing data, it is found that: The reservoir spaces of carbonate reservoir of ancient city area are mainly intergranular pore, intergranular dissolved pore, karst cave, structural fracture and diagenetic fracture. The reservoir of Yingshan formation in the ancient city area is mainly crack pore-cave reservoir, secondly fracture type reservoir, and, the porosity for the third section of Yingshan formation is relative development with large thickness which should be the key exploration target. The dolomite reservoir of Yingshan formation has the characters of multi layers, thin layers vertically and the different comparison in horizon. The lower part of high-quality dolomite reservoir in Yingshan formation is an important exploration area of carbonate reservoir in ancient city-low uplift. The studies, on the micro and macro development characteristics of the carbonate reservoir of ordovician-Yingshan formation in ancient city-low uplift, provide ideas and guidance for the exploration and deployment of the carbonate reservoir.
A review of the research on the lateral force resistance of cold-formed shear wall
Authors: Zhang Zhuangnan , Wang Yiyue , Yang Juncai
Published: March 2020

In this paper, the research on the lateral force resistance of the existing cold-formed thin-walled steel shear wall was briefly summarized. The innovation of the new cold-formed thin-walled steel composite wall proposed in recent years and the improvement of the existing structure system were described. According to the research situation of home and abroad, the future prospect and development direction of this system were put forward.
Analysis of Wide Box Gird’s Shear-lag Effect Based on Energy Method in Single-Cable-plane Cable Stayed Bridge
Authors: Tan Donglian , Li Xing
Published: March 2020

Box beam shear lag effect Of single cable plane cable-stayed bridge under moment and axial force is analyzed. The Yellow River bridge in Jinan as an example, the formula of shear lag under dead load has been set up using the Energy variation method. It is convenient and practical. The theoretical calculation results are in good agreement with those obtained in the solid finite element model calculation. The results show that the shear lag effect of cable-stayed bridge of single cable plane with wide box girder is bigger. It should be highly valued in the design.
Study on the Influence of the Thickness of Column on Axial Compression Behavior of Cold-Formed Steel Composite Wall
Authors: Wang Chungang , Qu Jiaxin , Liu Hong
Published: March 2020

By changing the thickness of the column, the axial compression behavior of the one-side sheathed wall and the both-sides sheathed wall can be altered at different levels. Simulation and inspection of cold-formed thin-walled steel frame wall had been finished by using a finite element simulation software called ABAQUS, which was applied by test data from relevant literature. The axial carrying capacity of the sheathed wall was superior than the unsheathed wall, therefore, all models had been built and studied based on the one-side sheathed wall and both-sides similar sheathed wall. The analysis results proved that the axial compression behavior of the one-side sheathed wall and the both-sides sheathed wall could be increased substantially by adding the thickness of studs, and this change was more sensitive to the influence of the wall with one-side sheathed wall especially.
Study on seepage characteristics of tight sandstone reservoir
Authors: Zhao Yongfu , Liu Chen , Li Jing , Xie Yetong , Kong Xiangchao , Liu Xuliang
Published: March 2020

Seepage characteristics of reservoir rocks are important factors affecting the effect of tight oil and gas production. Therefore the pore structure of tight sandstone from Dong 6 well in 4 block of the central Dzungaria Basin were studied by mercury injection experiment, and the seepage characteristics of tight sandstone were comprehensively studied by stress sensitivity experiment. The results show that: the pore throat distribution of the tight sandstone in the study area is not uniform, but the sorting property is good. The pore throat which promotes the permeability is mainly distributed near the threshold pressure of mercury injection experiment. The stress sensitivity of tight sandstone is affected by stress state and pore structure. Stress sensitivity is negatively correlated with confining pressure, and permeability loss is negatively correlated with pore throat radius.
Research on Deterioration Model of Concrete Road in Cold Area
Authors: Jin Cheng , Zhang Yiduo
Published: March 2020

Based on the concrete damage data under the interaction of fatigue loads and freeze-thaw cycles, a concrete freeze-thaw cycle deterioration model and a fatigue damage deterioration model are established respectively. Based on the concrete fatigue damage deterioration model, a freeze-thaw influence factor is introduced, and a freeze-thaw The model of concrete degradation under fatigue and fatigue, and the relationship between freeze-thaw damage, fatigue damage and time are discussed separately, so as to study the remaining life of concrete roads.
Seismic Stability Analysis of Loess Landslide Based on Orthogonal Test
Authors: Zhao Juan , Mu Peng
Published: March 2020

A numerical model of a loess landslide is established by using numerical simulation method to simulate the stability of the loess landslide under earthquake load. The results show that the loess landslide is stable before the earthquake and instable under the earthquake. The horizontal displacement and shear strain increment of the front part of the sliding slope increase obviously under the earthquake. At the same time, the sensitivity analysis of the seismic stability of the loess landslide is carried out by using the orthogonal test design method. The results show that the seismic action is the second factor to the internal friction angle of the sliding zone soil. With the increase of the seismic intensity, the decrease trend of the stability coefficient increases.
Literature Review: How in-channel aquatic vegetation (IAV) affects hyporheic exchange (HE)
Authors: Ding Mengda , Wan Jingfang , Li Qiang , Tang Bing
Published: March 2020

Worldwide increasing demand of water both in both quantity and quality requires more understand of correlation of in-channel aquatic vegetation (IAV) with water purification, since IAV removal from waterways is commonly used for flowrate regulation. Hyporheic zone (HZ) is where is the connection area of surface runoff and subsurface flow, plays an important role of water self-purification. Based on current literatures, the mechanism of IAV impaction on HE is illustrated with a conceptual model that demonstrates 3 pathways, including biological approach, surface runoff approach and subsurface flow approach. Further experimental research is required due to the uncertainty and counteracts of the influence factors make its correlation ambiguous.
Analysis of influence factors and stability of concrete-filled steel tube arch bridge
Authors: Wang Jinzhi , Guo Junfeng
Published: March 2020

A structural calculation model of a fly-bird-type concrete-filled steel tube arch bridge was established by using large general finite element software. The stability of the bridge during construction and in each working condition was numerically simulated and analysed. Linear elasticity, geometric nonlinearity and material nonlinearity stability safety factors were calculated and their influences on the stability were compared. At the same time, the main influence factors of the fly-bird-type concrete-filled steel tube arch bridge stability are discussed, the influences of the wind bracing number, form and stiffness on the bridge stability are calculated and analysed, and the reasonable values or forms range and the structural stability influencing factors under different value conditions are studied.
The effect of rise-span ratio on the rigid-framed arch bridges
Authors: Guo Junfeng , Liu Yong
Published: March 2020

The rigid-framed arch structure is a popular bridge structure on medium and small span bridge such as flyover. Rise-span ratio affects the rigid-framed arch structure performance, in order to analyse the influence on the rigid-framed arch structure of different rise-span ratio, a calculation model of the rigid-framed arch structure on the basis of the project established using the large general finite element software, by adjusting the rise value to change the rise-span ratio, analysing and comparing the structural internal force and deformation condition of the rigid-framed arch in different rise-span ratio under the action of constant live load, temperature change, and foundation settlement. The influence of different rise-span ratio on the rigid-framed arch stress summarized.
Take-Off Trajectory Optimization of Tilt-rotor Aircraft Based on Direct Allocation Method
Authors: Gao Jiaxin , Zhang Qian , Chen Jiyang , Wang Xueyun
Published: March 2020

During the take-off stage, the tilt-rotor aircraft’s actuator is redundant and difficult to control. In order to take off more quickly and safety reach horizontal flight state with less power consumption, the take-off trajectory is necessary to be optimized. this paper introduces the direct allocation method to optimize the take-off trajectory of tilt-rotor aircraft. Firstly, the dynamic model of the take-off stage of the tilt-rotor aircraft is established. According to the actual flight conditions, the constraints and the optimization objective function of the take-off process are established. Then, the entire take-off process is divided into several segments according to time, and the continuous optimal control problem is discretized into a nonlinear programming problem by using the direct allocation method. The state and control variables at each segment point and midpoint are taken for optimization. and then the optimized variables are fitted by the third-order Simpson method. Finally, GPOPS toolbox in MATLAB was used to solve the nonlinear programming problem. The simulation results show that the optimized take-off trajectory can well meet the boundary constraints, and its solutions are stable.
Design of a Single Motor Special Hybrid Transmission
Authors: Han Ying
Published: March 2020

The development of electric vehicle power system has become an important technical route of energy conservation and emission reduction. Hybrid system based on engine optimization is becoming a feasible technology at present. The motor and transmission system was integrated for the dedicated hybrid gearbox at the beginning of the design, with obvious advantages in performance and cost. Therefore, this design method has been favored by many automobile companies. In this paper, a single-motor multi-gear hybrid scheme is introduced, which can realize the pure electric mode with two gears and hybrid mode with four gears. At the same time, this scheme also has the advantages of compact mechanism and low product cost.
Study on Shafting Calibration Technology of INS/CNS Integrated Navigation System
Authors: Zhao Wangyang , Song Gaoling , Zhou Lingfeng , Wang Kai , Liu Juzhong
Published: March 2020

As a high precision attitude measurement device, the INS/CNS integrated navigation system has error order of second and installation and calibration precision of minute. The calibration residue of installation error directly affects attitude determination and positioning precision. The paper discusses calibration method of sub-system installation error, and expounds calibration principles of INS/CNS integrated navigation system. According to overall technical solutions, this paper studies shafting calibration error transfer characteristics of INS/CNS integrated navigation system, and puts forward calibration solution for the system. It mainly analyzes impact of multiple error factors during system calibration such as installation error and measurement instrument error on the integrated system, models and analyzes countershaft inclination effect, coaxial error and zero position calibration, optimizes calibration method for the system and improves installation error calibration precision.
Parallel Machines Parts Ordering Problem with Time Window
Authors: Cheng Bihui
Published: March 2020

in the classical sorting problem, the processing time of the job is usually a constant independent of the start time. However, in some sorting problems with strong practical background, the processing time of the job may have some relation with the starting time. It is divided into two cases, one is the processing time of the job is the increase function of the start time, the other is the processing time of the job is the decrease function of the start time. On the only one machine sorting problem with in time windows, this paper designs a 3/2-approximation algorithm for the parallel machiness parts sorting problem with in time windows, and its algorithm complexity is.
Temperature and nonlinear compensation of Hall current sensor based on least square method
Authors: Qi Fei , Zhao Xiaopeng , Huang Qian , Huang Hesong
Published: March 2020

In view of the temperature characteristics and non-linear problems of Hall current sensor, this paper introduces a method of temperature and nonlinear compensation based on least square method. On the basis of the curve fitting by the least square method, it is verified by the test data. This method can better compensate the influence of temperature and nonlinearity on the measurement errors of the Hall current sensor.