Composite action of notched circular CFT stub columns under axial compression

Fa-Xing Ding,Bing Wen,Xuemei Liu,Hai-bo Wang 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.24 No.3

This paper conducted both numerical and theoretical studies to investigate the composite action of notched circular concrete-filled steel tubular (CFT) stub columns under axial compression and established a theoretical method to predict their ultimate bearing capacity. 3D finite element (FE) analysis was conducted to simulate the composite action and the results were in good agreement with experimental results on circular CFT stub columns with differently oriented notches in steel tubes. Parametric study was conducted to understand the effects of different parameters on the mechanical behavior of circular CFT stub columns and also the composite action between the steel tube and the core concrete. Based on the results, a theoretical formula was proposed to calculate the ultimate bearing capacity of notched CFT stub columns under compression with consideration of the composite action between the steel tube and the core concrete.

Flexural stiffness of steel-concrete composite beam under positive moment

Fa-Xing Ding,Jing Liu,Xuemei Liu,Feng-Qi Guo,Li-Zhong Jiang 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.20 No.6

This paper investigates the flexural stiffness of simply supported steel-concrete composite I-beams under positive bending moment through combined experimental, numerical, and different standard methods. 14 composite beams are tested for experimental study and parameters including shear connection degree, transverse and longitudinal reinforcement ratios, loading way are also investigated. ABAQUS is employed to establish finite element (FE) models to simulate the flexural behavior of composite beams. The influences of a few key parameters, such as the shear connection degree, stud arrangement, stud diameter, beam length, loading way, on the flexural stiffness is also studied by parametric study. In addition, three widely used standard methods including GB, AISC, and British standards are used to estimate the flexural stiffness of the composite beams. The results are compared with the experimental and numerical results. The findings have provided comprehensive understanding of the flexural stiffness and the modelling of the composite beams. The results also indicate that GB 50017-2003 could provide better results in comparison to the other standards.

Behavior of circular thin-walled steel tube confined concrete stub columns

Fa-Xing Ding,Liu Tan,Xuemei Liu,Liping Wang 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.23 No.2

This paper presents a combined numerical and theoretical study on the composite action between steel and concrete of circular steel tube confined concrete (STCC) stub columns under axial compressive loading with a full theoretical elasto-plastic model and finite element (FE) model in comparison with experimental results. Based on continuum mechanics, the elasto-plastic model for STCC stub columns was established and the analysis was realized by a FORTRAN program and the three dimensional FE model was developed using ABAQUS. The steel ratio of the circular STCC columns were defined in range of 0.5% to 2% to analyze the composite action between steel tube and concrete, and make a further study on the advantages of the circular STCC columns. By comparing the results using the elasto-plastic methods with the parametric analysis result of FE model, the appropriate friction coefficient between the steel tube and core concrete was defined as 0.4 to 0.6. Based on ultimate balance theory, the formula of ultimate load capacity applying to the circular STCC stub columns was developed.

Study on flexural capacity of simply supported steel-concrete composite beam

Fa-Xing Ding,Jing Liu,Xuemei Liu,Zhi-wu Yu 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.4

This paper investigates the flexural capacity of simply supported steel-concrete composite I beam and box beam under positive bending moment through combined experimental and finite element (FE) modeling. 24 composite beams are included into the experiments and parameters including shear connection degree, transverse reinforcement ratio, section form of girder, diameter of stud and loading way are also considered and investigated. ABAQUS is employed to establish FE models to simulate the behavior of composite beams. The influences of a few key parameters, such as the shear connection degree, stud arrangement, stud diameter, beam length and loading way, on flexural capacity are discussed. In addition, three methods including GB standard, Eurocode 4, and Nie method are also used to estimate the flexural capacity of composite beams and also for comparison with experimental and numerical results. The results indicate that Nie method may provide a better estimation in comparison to other two standards.

The Influence of Moisture Content on Shrinkage of Wool Fabrics during Domestic Tumble Drying Process

Wei Bao,Jinsong Shen,Xuemei Ding 한국섬유공학회 2021 Fibers and polymers Vol.22 No.2

Shrinkage of wool fabrics caused during tumble drying is a serious defect. In the drying process, the feltingshrinkage of wool fabrics was influenced by the moisture content and temperature of wool fabric as well as mechanical actionbeing applied on the wool fabric. In the current study, the relationship between moisture content of wool fabrics andshrinkage was studied in the drying programs under no heating condition or heated condition. This study also analyzedshrinkage behaviors of the untreated wool fabric and the Chlorine-Hercosett treated wool fabric with different moisturecontents. For the untreated wool fabric, moisture content in the fabric could influence the mechanical properties of woolfibers, resulting in the different extent of felting shrinkage of wool fabric during tumble drying. For the Chlorine-Hercosetttreated wool fabric at different initial moisture contents, there was no obvious variation in the length change under no heatingcondition, but a slight difference in the shrinkage under heated condition. The study could lead to the new guidance forefficient drying of wool fabric with less felting shrinkage.

Knowledge roadmap of sustainable development in the textile and apparel industry: a scientometric analysis

Zhaoshan Wu,Liya Zhou,Xuemei Ding,Xiongying Wu,Laili Wang 한국의류학회 2022 Fashion and Textiles Vol.9 No.1

Practices in the textile and apparel industry (TAI) have led to numerous environmental and social problems, which have prompted extensive research on the sustainable development of the textile and apparel industry (SDTAI). This paper presents a comprehensive and quantitative analysis of the status quo in the SDTAI domain using scientometrics. From 1987 to 2019, the Web of Science core collection databases (SCI and SSCI) included 863 journal articles related to SDTAI, and our analysis results were as follows: (1) 60 critical research keywords occur in the knowledge base; (2) four research hotspots were identifed; (3) fve themes constituted the main knowledge area; and (4) based on the knowledge base, research hotspot, and knowledge domain, the knowledge structure consisted of nine subjects and fve systems. This paper proposes a knowledge roadmap that can be helpful for practitioners and academicians to better understand the current sustainable development status and trends in the TAI.

Effects of age and diet forms on growth-development patterns, serum metabolism indicators, and parameters of body fat deposition in Cherry Valley ducks

Lv Gang,Zeng Qiufeng,Ding Xuemei,Bai Shiping,Zhang Keying 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.2

Objective: This study was conducted to investigate the effects of age and diet forms on growth-development patterns, serum metabolism indicators, and parameters of body fat deposition in Cherry Valley ducks. Methods: According to the hatching age and initial weight, a total of 150 1-day-old male SM3 Cherry Valley ducks were randomly assigned to two diet forms (pellet vs powder form). Each treatment had with 5 replicates per treatment and 15 meat ducks per replicate. The study lasted 42 d, which was divided into two periods (1 to 21 vs 22 to 42 d). Results: Our results showed that compared with powder group, ducks in pellet group had greater growth performance during different period (p<0.05). The inflection point was 24 d and was not numerically affected by diet forms. Increasing age (42 vs 21 d) significantly increased the weight of body fat and hepatic fat metabolism related enzyme activities in ducks (p<0.05), meanwhile, increasing age (42 vs 21 d) improved serum metabolism indicators and decreased mRNA expression levels of fat metabolism-related genes in liver (p<0.05). Ducks fed different diets (pellet vs powder form) increased growth performance as well as the weight of body fat and improved serum metabolism indicators (p<0.05). In addition, interactions were found between age and diet forms on the levels of serum metabolism indicators in ducks (p<0.05). Conclusion: In conclusion, powder feed reduced growth performance of ducks, and the day of inflection point was 24 days old. Ducks with higher age or fed with pellet diet showed higher fat deposition. The effect of age and feed forms on body fat deposition might result from changes in the contents of serum metabolism indicators, key enzyme activity of lipid production, and hepatic gene expressions. Objective: This study was conducted to investigate the effects of age and diet forms on growth-development patterns, serum metabolism indicators, and parameters of body fat deposition in Cherry Valley ducks.Methods: According to the hatching age and initial weight, a total of 150 1-day-old male SM3 Cherry Valley ducks were randomly assigned to two diet forms (pellet vs powder form). Each treatment had with 5 replicates per treatment and 15 meat ducks per replicate. The study lasted 42 d, which was divided into two periods (1 to 21 vs 22 to 42 d).Results: Our results showed that compared with powder group, ducks in pellet group had greater growth performance during different period (p<0.05). The inflection point was 24 d and was not numerically affected by diet forms. Increasing age (42 vs 21 d) significantly increased the weight of body fat and hepatic fat metabolism related enzyme activities in ducks (p<0.05), meanwhile, increasing age (42 vs 21 d) improved serum metabolism indicators and decreased mRNA expression levels of fat metabolism-related genes in liver (p<0.05). Ducks fed different diets (pellet vs powder form) increased growth performance as well as the weight of body fat and improved serum metabolism indicators (p<0.05). In addition, interactions were found between age and diet forms on the levels of serum metabolism indicators in ducks (p<0.05).Conclusion: In conclusion, powder feed reduced growth performance of ducks, and the day of inflection point was 24 days old. Ducks with higher age or fed with pellet diet showed higher fat deposition. The effect of age and feed forms on body fat deposition might result from changes in the contents of serum metabolism indicators, key enzyme activity of lipid production, and hepatic gene expressions.

Dietary phosphorus deficiency impaired growth, intestinal digestion and absorption function of meat ducks

Huimin Xu,Shujun Dai,Keying Zhang,Xuemei Ding,Shiping Bai,Jianping Wang,Huanwei Peng,Qiufeng Zeng 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.12

Objective: An experiment was conducted to investigate the effects of dietary non-phytate phosphorus (nPP) deficiency on intestinal pH value, digestive enzyme activity, morphology, nutrient utilization, and gene expression of NaPi-IIb in meat ducks from 1 to 21 d of age. Methods: A total of 525 one-d-old Cherry Valley ducklings were fed diets (with 7 pens of 15 ducklings, or 105 total ducklings, on each diet) with five levels of nPP (0.22%, 0.34%, 0.40%, 0.46%, or 0.58%) for 21 d in a completely randomized design. Five experimental diets contained a constant calcium (Ca) content of approximately 0.9%. Body weight (BW), body weight gain (BWG), feed intake (FI), and feed to gain ratio (F:G) were measured at 14 and 21 d of age. Ducks were sampled for duodenum and jejunum digestion and absorption function on 14 and 21 d. Nutrient utilization was assessed using 25- to 27-d-old ducks. Results: The results showed ducks fed 0.22% nPP had lower (p<0.05) growth performance and nutrient utilization and higher (p<0.05) serum Ca content and alkaline phosphatase (ALP) activity. When dietary nPP levels were increased, BW (d 14 and 21), BWG and FI (all intervals), and the serum phosphorus (P) content linearly and quadratically increased (p<0.05); and the jejunal pH value (d 14), duodenal muscle layer thickness (d 14), excreta dry matter, crude protein, energy, Ca and total P utilization linearly increased (p<0.05); however, the serum ALP activity, jejunal Na+-K+-ATPase activity, and duodenal NaPi-IIb mRNA level (d 21) linearly decreased (p<0.05). Conclusion: The results indicated that ducks aged from 1 to 21 d fed diets with 0.22% nPP had poor growth performance related to poor intestinal digestion and absorption ability; but when fed diets with 0.40%, 0.46%, and 0.58% nPP, ducks presented a better growth performance, intestinal digestion and absorption function.