Experimental research on seismic behavior of steel reinforced high-strength concrete short columns

Weiqing Zhu,Jinqing Jia,Junguang Zhang 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.25 No.5

This experimental research presents the seismic performance of steel reinforced high-strength concrete (SRHC) short columns. Eleven SRHC column specimens were tested under simulated earthquake loading conditions, including six short column specimens and five normal column specimens. The parameters studied included the axial load level, stirrup details and shear span ratio. The failure modes, critical region length, energy dissipation capacity and deformation capacity, stiffness and strength degradation and shear displacement of SRHC short columns were analyzed in detail. The effects of the parameters on seismic performance were discussed. The test results showed that SRHC short columns exhibited shear-flexure failure characteristics. The critical region length of SRHC short columns could be taken as the whole column height, regardless of axial load level. In comparison to SRHC normal columns, SRHC short columns had weaker energy dissipation capacity and deformation capacity, and experienced faster stiffness degradation and strength degradation. The decrease in energy dissipation and deformation capacity due to the decreasing shear span ratio was more serious when the axial load level was higher. However, SRHC short columns confined by multiple stirrups might possess good seismic behavior with enough deformation capacity (ultimate drift ratio ≥ 2.5%), even though a relative large axial load ratio (= 0.38) and relative small structural steel ratio (= 3.58%) were used, and were suitable to be used in tall buildings in earthquake regions.

연애 리얼리티 프로그램 몰입 및 지속시청 의도에 영향을 미치는 요인에 관한 연구

공유경(Weiqing Kong),주만화(Manhua Zhu),정용국(Yongkuk Chung) 한국콘텐츠학회 2023 한국콘텐츠학회논문지 Vol.23 No.3

본 연구는 연애 리얼리티 TV 프로그램에 대한 시청자들의 몰입 및 지속시청 의도에 영향을 미치는 요인들을 살펴보았다. 영향 요인은 크게 연애 관련 신념과 태도(연애관계 효능감, 첫눈에 반하는 태도, 연애에 대한 이상적 기대), 시청에 대한 심리적 경험(인지된 현실감, 공감, 대리만족), 시청 행태(수용 활동, 확산 활동)로 구분하였다. 연애 리얼리티 프로그램의 주 시청층인 20대를 대상으로 온라인 설문조사를 실시하였다. 주요 연구 결과는 다음과 같다. 먼저 프로그램 몰입과 관련이 높은 변인은 대리만족, 연애에 대한 이상적 기대, 수용행위 순으로 나타났다. 이는 자신이 할 수 없는 일을 타인이 해내는 것을 보며 느끼는 만족감이 클수록, 연애에 대한 이상적 혹은 비현실적 기대가 클수록, 프로그램에 대한 타인의 의견을 더 많이 접할수록 몰입도가 높아진다는 것을 의미한다. 다음으로 지속시청 의도와 관련이 높은 변인은 대리만족, 인지된 현실감, 연애에 대한 이상적 기대 순으로 나타났다. 이는 타인을 보며 느끼는 만족감이 클수록, 프로그램 내용이 현실과 부합한다고 느낄수록 지속시청 의도가 높다는 것을 의미한다. This study examined factors influencing a viewer’s immersion and intention to continuous watching of dating reality TV shows. The factors were classified into three categories including personal beliefs and attitudes toward romance, psychological viewing experiences, and viewing behaviors. We conduced an online survey on 217 viewers and major findings were as follows. First, factors related to immersion were vicarious satisfaction, ideal expectations for romance, acceptance behavior of social viewing, respectively. Second, factors relevant to intention to continuous watching were vicarious satisfaction, perceived reality, ideal expectations for romance, respectively. Theoretical and practical implications of the results were discussed.

Morphological, Physiological and Biochemical Responses of Gerbera Cultivars to Heat Stress

Chen, Wen,Zhu, Xiaoyun,Han, Weiqing,Wu, Zheng,Lai, Qixian Korean Society of Horticultural Science 2016 원예과학기술지 Vol.34 No.1

Heat stress is an agricultural problem for Gerbera jamesonii, and it often causes poor seedling growth, reduced flower yield and undesirable ornamental characteristics of flowers. However, little is known about the effect of heat stress on the morphological, physiological and biochemical characteristics of gerbera plants. Here, the responses of six cultivars of Gerbera jamesonii to heat stress were investigated. Under a 1-d heat treatment at $45^{\circ}C$, the leaves of gerbera cultivars showed yellowing, wilting, drying and death to varying degrees. The heat treatment also resulted in increased electrical conductivity, decreased soluble protein and chlorophyll contents, and the accumulation of malondialdehyde (MDA) and proline in leaves. Moreover, heat tolerance differed among the six tested gerbera cultivars. Our results demonstrated that among the six gerbera cultivars, 'Meihongheixin' is a heat-resistant cultivar, whereas 'Beijixing' is a heat-sensitive one. 'Shijihong' and 'Linglong' are relatively heat-resistant cultivars, and 'Dadifen' and 'Taiyangfengbao' are relatively heat sensitive.

Mechanical behaviour of concrete filled double skin steel tubular stub columns confined by FRP under axial compression

Jun Wang,Weiqing Liu,Ding Zhou,Lu Zhu,Hai Fang 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.4

The present study focuses on the mechanical behaviour of concrete filled double skin steel tubular (CFDST) stub columns confined by fiber reinforced polymer (FRP). A series of axial compression tests have been conducted on two CFDST stub columns, eight CFDST stub columns confined by FRP and a concrete-filled steel tubular (CFST) stub column confined by FRP, respectively. The influences of hollow section ratio, FRP wall thickness and fibre longitudinal-circumferential proportion on the load-strain curve and the concrete stress-strain curve for stub columns with annular section were discussed. The test results displayed that the FRP jacket can obviously enhance the carrying capacity of stub columns. Based on the test results, a new model which includes the effects of confinement factor, hollow section ratio and lateral confining pressure of the outer steel tube was proposed to calculate the compressive strength of confined concrete. Using the present concrete strength model, the formula to predict the carrying capacity of CFDST stub columns confined by FRP was derived. The theoretically predicted results agree well with those obtained from the experiments and FE analysis. The present method is also adapted to calculate the carrying capacity of CFST stub columns confined by FRP.

Morphological, Physiological and Biochemical Responses of Gerbera Cultivars to Heat Stress

Wen Chen,Xiaoyun Zhu,Weiqing Han,Zheng Wu,Qixian Lai 한국원예학회 2016 원예과학기술지 Vol.34 No.1

Heat stress is an agricultural problem for Gerbera jamesonii, and it often causes poor seedling growth, reduced flower yield and undesirable ornamental characteristics of flowers. However, little is known about the effect of heat stress on the morphological, physiological and biochemical characteristics of gerbera plants. Here, the responses of six cultivars of Gerbera jamesonii to heat stress were investigated. Under a 1-d heat treatment at 45°C, the leaves of gerbera cultivars showed yellowing, wilting, drying and death to varying degrees. The heat treatment also resulted in increased electrical conductivity, decreased soluble protein and chlorophyll contents, and the accumulation of malondialdehyde (MDA) and proline in leaves. Moreover, heat tolerance differed among the six tested gerbera cultivars. Our results demonstrated that among the six gerbera cultivars, ‘Meihongheixin’ is a heat-resistant cultivar, whereas ‘Beijixing’ is a heatsensitive one. ‘Shijihong’ and ‘Linglong’ are relatively heat-resistant cultivars, and ‘Dadifen’ and ‘Taiyangfengbao’ are relatively heat sensitive.

Energy absorption of foam-filled lattice composite cylinders under lateral compressive loading

Jiye Chen,Yong Zhuang,Hai Fang,Weiqing Liu,Lu Zhu,Ziyan Fan 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.31 No.2

This paper reports on the energy absorption characteristics of a lattice-web reinforced composite sandwich cylinder (LRCSC) which is composed of glass fiber reinforced polymer (GFRP) face sheets, GFRP lattice webs, polyurethane (PU) foam and ceramsite filler. Quasi-static compression experiments on the LRCSC manufactured by a vacuum assisted resin infusion process (VARIP) were performed to demonstrate the feasibility of the proposed cylinders. Compared with the cylinders without lattice webs, a maximum increase in the ultimate elastic load of the lattice-web reinforced cylinders of approximately 928% can be obtained. Moreover, due to the use of ceramsite filler, the energy absorption was increased by 662%. Several numerical simulations using ANSYS/LS-DYNA were conducted to parametrically investigate the effects of the number of longitudinal lattice webs, the number of transverse lattice webs, and the thickness of the transverse lattice web and GFRP face sheet. The effectiveness and feasibility of the numerical model were verified by a series of experimental results. The numerical results demonstrated that a larger number of thicker transverse lattice webs can significantly enhance the ultimate elastic load and initial stiffness. Moreover, the ultimate elastic load and initial stiffness were hardly affected by the number of longitudinal lattice webs.

Influence of slenderness on axially loaded square tubed steel-reinforced concrete columns

Biao Yan,Dan Gan,Xuhong Zhou,Weiqing Zhu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.3

This paper aims to investigate the axial load behavior and stability strength of square tubed steel-reinforced concrete (TSRC) columns. Unlike concrete filled steel tubular (CFST) column, the outer steel tube of a TSRC column is mainly used to provide confinement to the core concrete. Ten specimens were tested under axial compression, and the main test variables included length-to-width ratio (<i>L/B</i>) of the specimens, width-to-thickness ratio (<i>B/t</i>) of the steel tubes, and with or without stud shear connectors on the steel sections. The failure mode, ultimate strength and load-tube stress response of each specimen were summarized and analyzed. The test results indicated that the axial load carried by square tube due to friction and bond of the interface increased with the increase of <i>L/B</i> ratio, while the confinement effect of tube was just the opposite. Parametric studies were performed through ABAQUS based on the test results, and the feasibility of current design codes has also been examined. Finally, a method for calculating the ultimate strength of this composite column was proposed, in which the slenderness effect on the tube confinement was considered.