scholarly journals Effects of Vehicle-Induced Vibrations on the Tensile Performance of Early Age PVA-ECC

2019 ◽  
Author(s):  
Xiaodong Zhang ◽  
Shuguang Liu ◽  
Changwang Yan ◽  
Xiaoxiao Wang ◽  
Huiwen Wang
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Correlation Analysis ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Early Age ◽  
Grey Correlation ◽  
Tensile Performance ◽  
Grey Correlation Analysis ◽  
The Impact

The purpose of this study was to conduct laboratory test programs on how much vehicle-induced vibrations during early ages affected the tensile performance of Polyvinyl alcohol-engineering cementitious composites (PVA-ECC). A self-improved device was used to simulate the vehicle-induced vibrations, and after vibrating with the designed variables, both a uniaxial tensile test and a grey correlation analysis were performed. The results indicated that: the effects of vehicle-induced vibrations on the tensile performance of early age PVA-ECC were significant, and they generally tended to be negative in this investigation. In particular, for all of the vibrated PVA-ECC specimens, the most negative age when vibrated occurred during the period between the initial set and the final set. In this period, the effects of the vibration duration on the tensile performance of the PVA-ECC tended to be negative overall, but the impact trend and the degree varied for the corresponding lengths of duration and levels of frequency. The cracking strength was the most sensitive to the variables in this investigation, and then it followed the ultimate tensile strength and strain. The grey correlation analysis was applicable in analyzing the effects of vehicle-induced vibrations on the tensile performance of early age PVA-ECC.

scholarly journals Effects of Vehicle-Induced Vibrations on the Tensile Performance of Early-Age PVA-ECC

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2652 ◽  
Author(s):  
Xiaodong Zhang ◽  
Shuguang Liu ◽  
Changwang Yan ◽  
Xiaoxiao Wang ◽  
Huiwen Wang
Keyword(s):  
Correlation Analysis ◽  
Bridge Deck ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Early Age ◽  
Negative Effects ◽  
Grey Correlation ◽  
Tensile Performance ◽  
Grey Correlation Analysis ◽  
Inherent Strain

Polyvinyl alcohol-engineering cementitious composites (PVA-ECCs) have been widely applied in bridge deck repairing or widening, and a common practice is that a portion of the bridge is left open to traffic while the closed portion is constructed, which exposes the early-age PVA-ECC to vehicle-induced vibrations. However, whether vehicle-induced vibrations affect the performance of early-age PVA-ECC remains unknown. The purpose of this study was to conduct laboratory test programs to investigate to what extent vehicle-induced vibrations soon after installation affects the tensile performance of the PVA-ECC. A self-improved device was used to simulate the vehicle-induced vibrations, and after vibrating with the designed variables, both a uniaxial tensile test and a grey correlation analysis were performed. The results indicated that the effects of vehicle-induced vibrations on the tensile performance of early-age PVA-ECCs were significant, and they generally tended to be negative. In particular, for all of the vibrated PVA-ECC specimens, the most negative effects occurred when vibration occurred during the period between the initial set and the final set. We concluded that although vehicle-induced vibrations during the setting periods had no substantial effects on the inherent strain-hardening characteristics of PVA-ECCs, the effects should not be ignored.

scholarly journals Effects of Vehicle-Induced Vibrations on the Tensile Performance of Early Age PVA-ECC

2019 ◽  
Author(s):  
Xiaodong Zhang ◽  
Shuguang Liu ◽  
Changwang Yan ◽  
Xiaoxiao Wang ◽  
Huiwen Wang
Keyword(s):  
Correlation Analysis ◽  
Bridge Deck ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Early Age ◽  
Grey Correlation ◽  
Tensile Performance ◽  
Grey Correlation Analysis ◽  
The Common ◽  
Inherent Strain

Polyvinyl alcohol-engineering cementitious composites (PVA-ECC) has been widely applied in bridge deck repairing or widening, the common practice for doing this is that a portion of a bridge is left open to traffic while the closed portion is constructed, which expose the early age PVA-ECC to the vehicle-induced vibrations. However, whether vehicle-induced vibrations affect the tensile performance of early age PVA-ECC remains unknow. The purpose of this study was to conduct laboratory test programs on how much vehicle-induced vibrations during early ages affected the tensile performance of PVA-ECC. A self-improved device was used to simulate the vehicle-induced vibrations, and after vibrating with the designed variables, both a uniaxial tensile test and a grey correlation analysis were performed. The results indicated that: the effects of vehicle-induced vibrations on the tensile performance of early age PVA-ECC were significant, and they generally tended to be negative in this investigation. In particular, for all of the vibrated PVA-ECC specimens, the most negative age when vibrated occurred during the period between the initial set and the final set. We concluded that although vehicle-induced vibrations during the setting periods had no substantial effects on the inherent strain-hardening characteristics of PVA-ECC, the effects should not be ignored.

Using grey relational analysis to analyze influential factor of hand, foot and mouth disease in Shenzhen

2019 ◽  
Vol 9 (2) ◽  
pp. 197-206
Author(s):  
Xiaoyi He ◽  
Liping Li ◽  
Xiaojian Liu ◽  
Yongsheng Wu ◽  
Shujiang Mei ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Gross Domestic Product ◽  
Foot And Mouth Disease ◽  
Domestic Product ◽  
Content Type ◽  
Grey Correlation ◽  
Grey Correlation Analysis ◽  
Environmental Air ◽  
The Impact ◽  
Socio Economic Factors

Purpose Hand, foot and mouth disease (HFMD) is a common infectious disease in infants and children. HFMD has caused millions of cases and a large epidemic worldwide. A number of studies have shown that the incidence of HFMD is closely related to various factors such as meteorological factors, environmental air pollution factors and socio-economic factors. However, there are few studies that systematically consider the impact of various factors on the incidence of HFMD. The paper aims to discuss these issues. Design/methodology/approach This study used grey correlation analysis and principal component analysis (PCA) method to systematically analyse the impact of meteorological factors, health resource factors, socio-economic factors and environmental air pollution factors on the incidence of HFMD in Shenzhen. Findings The incidence of HFMD in Shenzhen was affected by multiple factors. Grey correlation analysis found eight influencing factors which are as follows: volume of industrial waste gas emission; the days of air quality equal to or above grade; the volume of industrial nitrogen oxide emission; precipitation; the mean air temperature; the gross domestic product; the expenditure for medical and health care; and the gross domestic product per capita. PCA found that the gross domestic product, the volume of industrial soot emission, the relative humidity, and the days of air quality equal to or above grade have a higher load value. Originality/value This study is the one of the first studies that apply the grey correlation analysis to analyse the influencing factors of HFMD in the English literature, which to some extent fills up the blank in this field.

scholarly journals Strength Behaviour of Hot Die Steel with Respect to its Heat Treatment

2020 ◽  
Vol 9 (1) ◽  
pp. 2100-2102
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Tensile Strength ◽  
Tensile Test ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Austenitizing Temperature ◽  
Tempering Temperature ◽  
Die Steel ◽  
The Impact

The surface temperature of hot die steel reaches typically up to 550ºC or above during processes like hot extrusion and casting non-ferrous material. The present paper explores the impact of austenitizing temperature as well as tempering temperature on the tensile strength of hot die steel. Heat treatment is done at three different austenitizing temperatures of 1010ºC, 1030ºC, and 1050ºC, followed by tempering done at two different temperatures of 540ºC and 580°C. Tempering is done twice for two hours. Metallographic grinding, polishing, and then etching using 2% Nital is done to investigate the microstructure of hot die steel with respect to its heat treatment. It is found that the grain size of hot die steel increases with an increase in austenitizing temperature. The impact on tensile strength of hot die steel for its heat treatment is examined by conducting the uniaxial tensile test to fracture. And investigation of the morphology of the fracture surface produced after the tensile test is done. It was found that hot die steel with large grain size exhibits lesser tensile strength. Whereas, the one having smaller grain has higher tensile strength that is found to be in accordance with the Hall-Patch equation

Grey correlation analysis on the synergistic development between innovation-driven strategy and marine industrial agglomeration: based on China's coastal provinces

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sheng Xu ◽  
Qingde Yue ◽  
Binbin Lu
Keyword(s):  
Correlation Analysis ◽  
Relational Model ◽  
Industrial Agglomeration ◽  
Integration Process ◽  
Content Type ◽  
Original Algorithm ◽  
Grey Correlation ◽  
Correlation Degree ◽  
Grey Correlation Analysis ◽  
The Impact

PurposeThe implementation of the innovation-driven development strategy is of practical significance for improving the quality and efficiency of economic growth and accelerating the transformation of economic development mode. The purpose of this paper is to study the impact of innovation-driven strategies on marine industry agglomeration and industrial transformation.Design/methodology/approachIn traditional grey correlation analysis, when the positive and negative areas cancel each other out during the integration process, the calculation result of the correlation degree is often inconsistent with the qualitative analysis. For this reason, from the perspective of curve similarity, this paper constructs two response curves through the relative change area of the two curves and the relative area change ratio of similar degree, thus constructing an improved grey relational model.FindingsThe authors find that the innovation investment has a better correlation with marine industrial agglomeration. It also found that Guangdong Province has the highest degree of correlation between innovation indicators and marine industrial agglomeration. Much beyond the authors’ expectation, in the areas where marine industrial agglomeration is high, the synergistic effect is not obvious by using the location entropy method.Originality/valueThe improved grey correlation analysis method can effectively overcome the phenomenon that the positive and negative areas cancel each other in the integration process of the original algorithm, and it can also effectively measure the negative correlation between variables. This paper explores the impact of innovation drive on the agglomeration of marine industries, which is of great significance to the sustainable development of marine economy.

scholarly journals Microstructure and Mechanical Properties of M50 Steel by Combining Cold Rolling with Austempering

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 381
Author(s):  
Dongsheng Qian ◽  
Yuangeng He ◽  
Feng Wang ◽  
Yun Chen ◽  
Xiaohui Lu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Cold Rolling ◽  
Charpy Impact ◽  
Uniaxial Tensile ◽  
Microstructure And Mechanical Properties ◽  
Transmission Electron ◽  
The Impact ◽  
M50 Steel

The microstructure and mechanical properties of M50 steel subjected to combining cold rolling (CR) with austempering are investigated. The microstructure is characterized using X-ray diffraction and scanning and transmission electron microscopy. The mechanical properties are measured using the uniaxial tensile and Charpy impact tests. It is observed that an excellent combination of ultimate tensile strength (2536 MPa) and impact toughness (128 J) was achieved by combining austempering with CR; of which the ultimate tensile strength increased by 10% compared with traditional martensite quenching-tempering (Q-T) specimen and the impact absorbed energy exhibited 2.3 times of that in Q-T specimen. The observation of the microstructure indicates that CR obviously refines the thickness of bainite sheaves, which is favorable for the formation of ultrafine equiaxed ferrite during tempering.

Effect of Orientation on Mechanical Behavior of an Extruded Al Alloy

2008 ◽  
Author(s):  
M. A. Malik ◽  
I. Salam ◽  
W. Muhammad
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Strain Rate ◽  
Mechanical Behavior ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Transverse Orientation ◽  
Longitudinal Orientation

The extruded materials are extensively used in chemical, food and nuclear industry and generally offer a unique combination of strength and freedom with regard to design solutions. During extrusion, material flow occurs in the direction of applied force and as a result microstructure change. The process ultimately induces variation in the mechanical properties when tested along or across the extrusion direction. The uniaxial tensile test is a simple and versatile test to expose most of the mechanical properties of the materials required to ensure the reliability of the systems. In present study, the mechanical behavior of an Al-Mg-Si alloy extruded cylinder has been determined with the help of uniaxial tensile test in longitudinal and transverse orientations. The microstructural features revealed significant difference in two orientations and constituent particles were found aligned in the direction of extrusion. Tensile tests were conducted in displacement mode at different cross head speeds corresponding to strain rates ranging from 10−5 to 10−1 s−1. The tests were conducted at ambient temperature in air atmosphere. The data thus obtained include: yield strength, ultimate tensile strength, percent elongation and reduction of area. Comparing the trends of strength variation, the material shows higher yield strength in longitudinal orientation as compared to transverse orientation. A slight increase in the yield strength with increasing strain rate was found in both the orientations. The ultimate tensile strength in both the directions was found similar and there was no appreciable change with increasing strain rate. The elongation and reduction in area were found higher in the longitudinal orientation. The effect of strain rate on these properties was negligible up to maximum speed tested. In longitudinal orientation typical dimpled fracture was observed indicating deformation before failure. In transverse orientation shallow dimples were present. The present study revealed that the distribution of constituent particles in an extruded thick-walled cylinder has a pronounced effect on its mechanical behavior and fracture morphology.

Sign in / Sign up

Export Citation Format

Share Document