Effect of Heat Treatment on Microstructure and Properties of FGH4096M Superalloy Processed by Selective Laser Melting

Zhibo Hao,Tian Tian,Shiqing Peng,Changchun Ge,Xinggang Li,Chonglin Jia,Chuan Guo,Qiang Zhu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.8

A self-designed nickel-based superalloy, designated as FGH4096M, was prepared by selective laser melting (SLM). Differentheat treatments were performed to improve the mechanical properties of the SLM alloy through optimizing the microstructuresand the features of γ′ precipitates. Compared with the as-deposited alloy, the columnar grains with dendritic structuresand equiaxed structures were retained in the alloy after direct aging, but a large amount of tertiary γ′ phase precipitated,especially around the sub-grain boundaries, resulting in the highest tensile strength but the lowest elongation. During solidsolution and aging treatment (SSA), the recovery and recrystallization occurring in the alloy facilitated the grains to beequiaxed with the increase of solution temperature. For lower solution temperature (below 1100 ℃), the secondary γ′ precipitatesdecreased with the increase of solution temperature, while the tertiary γ′ precipitates from the subsequent agingprocess gradually increased; for higher solution temperature over 1100 ℃, exceeding the complete dissolution temperatureof the γ′ phase, only tertiary γ′ precipitates from the subsequent aging process were uniformly distributed in the alloy. Afterdouble solid solution (1170 ℃ + 1050 ℃) + aging heat treatment (DSSA), there were three sizes of γ′ precipitates in thealloy. In general, the SLM + SSA (1130 ℃) alloy obtained the best comprehensive properties, which could be related tothe homogenized microstructures and the uniform and dense distribution of single sized tertiary γ′ precipitates in the alloy.

중국 대학 농구리그(CUBA) 공식스폰서의 스폰서십 설득의도성과 스폰서 동일 시, 브랜드 자산, 스폰서 몰입 및 스폰서 충성도 간 구조적 관계

Tian Zhibo,김용만 한국사회체육학회 2023 한국사회체육학회지 Vol.- No.94

Purpose: The purpose of this study is to examine the relationships among sponsorship persuasion intentions, identification, brand equity, sponsor commitment, and sponsor loyalty in the official sponsor of the Chinese University Basketball Association. Method: We conducted a survey to evaluate the purpose of the research. The respondents were spectators selected from the four home games of the Chinese University Basketball Association. The survey was conducted using the Wenjuanxing online survey platform in China. This study utilized a self-administered method in which respondents read and answered the questionnaires. Among the samples, 384 effective samples were finally selected for analysis after excluding survey results with a low confidence level. The data were recorded and analyzed using PASW 23.0 for frequency and descriptive analyses, and AMOS 23.0 for confirmatory factor analysis and structural equation model testing. Results: Findings in the present study are as follows: First, it was found that sponsor familiarity, sponsor congruity, and sponsor effort had a positive effect on sponsor identification, but sponsor integrity did not have an impact. Second, it was found that sponsor identification had a positive effect on brand awareness and brand image. Third, it was found that brand equity had a positive effect on sponsor commitment. Fourth, sponsor commitment was shown to have a positive influence on sponsor loyalty. Conclusion: This study found that sponsorship persuasion intention, sponsor identification, brand equity, and sponsor commitment are important factors in sponsor loyalty. Therefore, we need to improve our rapport with sponsors by enhancing awareness of the relationship between the sponsor and the sports event. Only then will the spectators develop unwavering loyalty to the sponsor.

Multiple damages detection in beam based approximate waveform capacity dimension

Zhibo Yang,Xuefeng Chen,Shaohua Tian,Zhengjia He 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.5

A number of mode shape-based structure damage identification methods have been verified by numerical simulations or experiments for on-line structure health monitoring (SHM). However, many of them need a baseline mode shape generated by the healthy structure serving as a reference to identify damages. Otherwise these methods can hardly perform well when multiple cracks conditions occur. So it is important to solve the problems above. By aid of the fractal dimension method (FD), Qiao and Wang proposed a generalized fractal dimension (GFD) to detect the delamination damage. As a modification of GFD, Qiao and Cao proposed the approximate waveform capacity dimension (AWCD) technique to simplify the calculation of fractal and overcome the false peak appearing in the high mode shapes. Based on their valued work, this paper combined and applied the AWCD method and curvature mode shape data to detect multiple damages in beam. In the end, the identification properties of the AWCD for multiple damages have been verified by groups of Monte Carlo simulations and experiments.

Damage detection using the improved Kullback-Leibler divergence

Tian, Shaohua,Chen, Xuefeng,Yang, Zhibo,He, Zhengjia,Zhang, Xingwu Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.3

Structural health monitoring is crucial to maintain the structural performance safely. Moreover, the Kullback-Leibler divergence (KLD) is applied usually to asset the similarity between different probability density functions in the pattern recognition. In this study, the KLD is employed to detect the damage. However the asymmetry of the KLD is a shortcoming for the damage detection, to overcoming this shortcoming, two other divergences and one statistic distribution are proposed. Then the damage identification by the KLD and its three descriptions from the symmetric point of view is investigated. In order to improve the reliability and accuracy of the four divergences, the gapped smoothing method (GSM) is adopted. On the basis of the damage index approach, the new damage index (DI) for detect damage more accurately based on the four divergences is developed. In the last, the grey relational coefficient and hypothesis test (GRCHT) is utilized to obtain the more precise damage identification results. Finally, a clear remarkable improvement can be observed. To demonstrate the feasibility and accuracy of the proposed method, examples of an isotropic beam with different damage scenarios are employed so as to check the present approaches numerically. The final results show that the developed approach successfully located the damaged region in all cases effect and accurately.

Damage detection using the improved Kullback-Leibler divergence

Shaohua Tian,Xuefeng Chen,Zhibo Yang,Zhengjia He,Xingwu Zhang 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.48 No.3

Structural health monitoring is crucial to maintain the structural performance safely. Moreover, the Kullback-Leibler divergence (KLD) is applied usually to asset the similarity between different probability density functions in the pattern recognition. In this study, the KLD is employed to detect the damage. However the asymmetry of the KLD is a shortcoming for the damage detection, to overcoming this shortcoming, two other divergences and one statistic distribution are proposed. Then the damage identification by the KLD and its three descriptions from the symmetric point of view is investigated. In order to improve the reliability and accuracy of the four divergences, the gapped smoothing method (GSM) is adopted. On the basis of the damage index approach, the new damage index (DI) for detect damage more accurately based on the four divergences is developed. In the last, the grey relational coefficient and hypothesis test (GRCHT) is utilized to obtain the more precise damage identification results. Finally, a clear remarkable improvement can be observed. To demonstrate the feasibility and accuracy of the proposed method, examples of an isotropic beam with different damage scenarios are employed so as to check the present approaches numerically. The final results show that the developed approach successfully located the damaged region in all cases effect and accurately.

Multiple damages detection in beam based approximate waveform capacity dimension

Yang, Zhibo,Chen, Xuefeng,Tian, Shaohua,He, Zhengjia Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.5

A number of mode shape-based structure damage identification methods have been verified by numerical simulations or experiments for on-line structure health monitoring (SHM). However, many of them need a baseline mode shape generated by the healthy structure serving as a reference to identify damages. Otherwise these methods can hardly perform well when multiple cracks conditions occur. So it is important to solve the problems above. By aid of the fractal dimension method (FD), Qiao and Wang proposed a generalized fractal dimension (GFD) to detect the delamination damage. As a modification of GFD, Qiao and Cao proposed the approximate waveform capacity dimension (AWCD) technique to simplify the calculation of fractal and overcome the false peak appearing in the high mode shapes. Based on their valued work, this paper combined and applied the AWCD method and curvature mode shape data to detect multiple damages in beam. In the end, the identification properties of the AWCD for multiple damages have been verified by groups of Monte Carlo simulations and experiments.

The Relationship between Watching Motivation, Perceived Value, Place Attachment and Behavioral Loyalty: A Case of China Tennis Open

( Qiang Zhang ),( Zhibo Tian ),( Jianmin Shi ),( Wangda Guo ) 아시아스포츠융합과학회 2021 Asia Pacific Journal of Applied Sport Sciences Vol.2 No.2

PURPOSE The purpose of this study is to investigate a behavioral loyalty model of China Tennis Open spectators and validate the relationships among spectators’’ watching motivation, perceived value, place attachment and behavioral loyalty. METHOD The spectators at the China Tennis Open were targeted as the main research sample. A total of 400 questionnaires were collected. The collected data was analyzed by means of descriptive statistics, confirmatory factor analysis, structural equation modeling, and significance test of difference. RESULT (1) Motivation has a positive effect on perceived value and place attachment, but the behavioral loyalty is not affected. (2) Perceived value directly influence on behavioral loyalty. (3) Place attachment directly influence on behavioral loyalty. CONCLUSION Motivation has a limited influence on the behavioral loyalty. Place attachment and perceived value are important factors in behavioral loyalty of China Tennis Open spectators. The results of this study provides some practical suggestions for the organization, management of tennis events and a direction for future research.

Discrete Element Simulation of Macro and Micro Mechanical Properties of Round Gravel Material under Triaxial Stress

Shaokun Ma,Haijun Huang,Fapai Tian,Jian Gong,Jiabing Zhang,Zhibo Duan 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.5

In this study, the effects of relative density and confining pressure on the shear characteristics of round gravel are investigated using a large-scale triaxial apparatus and the discrete element method. A simple and efficient numerical method for simulating flexible membranes is introduced. The results show that the stress-strain curves develop from hardened to softened type with increasing relative density, while the stress-strain curves develop from softened to hardened type with increasing confining pressure. As the axial strain increases, the strong contact force chains are vertically distributed, and the larger the relative density and confining pressure, the greater the number and thickness of the strong contact force chains. In the shear process, the distribution of average normal and tangential contact forces show “peanut-shaped” and “petal-shaped”, respectively. The increase in relative density increases the anisotropy of the specimen, while the increase in confining pressure results in a decrease. A linear relationship exists between the macroscopic stress ratio and the anisotropy coefficient. The anisotropy coefficient of the normal contact force provides the greatest contribution to the macroscopic shear strength (about 55%), followed by the anisotropy coefficient of the contact normal (about 26%) and that of the tangential contact force (about 19%).