Experimental study on the seismic performance of concrete filled steel tubular laced columns

Zhi Huang,Lizhong Jiang,Y. Frank Chen,Yao Luo,Wang-Bao Zhou 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.6

Concrete filled steel tubular (CFST) laced columns have been widely used in high rise buildings in China. Compared to solid-web columns, this type of columns has a larger cross-section with less weight. In this paper, four concrete filled steel tubular laced columns consisting of 4 main steel-concrete tubes were tested under cyclic loading. Hysteresis and failure mechanisms were studied based on the results from the lateral cyclic loading tests. The influence of each design parameter on restoring forces was investigated, including axial compression ratio, slenderness ratio, and the size of lacing tubes. The test results show that all specimens fail in compression-bending-shear and/or compression-bending mode. Overall, the hysteresis curves appear in a full bow shape, indicating that the laced columns have a good seismic performance. The bearing capacity of the columns decreases with the increasing slenderness ratio, while increases with an increasing axial compression ratio. For the columns with a smaller axial compression ratio (< 0.3), their ductility is increased. Furthermore, with the increasing slenderness ratio, the yield displacement increases, the bending failure characteristic is more obvious, and the hysteretic loops become stouter. The results obtained from the numerical analyses were compared with the experimental results. It was found that the numerical analysis results agree well with the experimental results.

Bayesian forecasting approach for structure response prediction and load effect separation of a revolving auditorium

Zhi Ma,Chung-Bang Yun,Yan-Bin Shen,Feng Yu,Hua-Ping Wan,Yao-Zhi Luo 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.4

A Bayesian dynamic linear model (BDLM) is presented for a data-driven analysis for response prediction and load effect separation of a revolving auditorium structure, where the main loads are self-weight and dead loads, temperature load, and audience load. Analyses are carried out based on the long-term monitoring data for static strains on several key members of the structure. Three improvements are introduced to the ordinary regression BDLM, which are a classificatory regression term to address the temporary audience load effect, improved inference for the variance of observation noise to be updated continuously, and component discount factors for effective load effect separation. The effects of those improvements are evaluated regarding the root mean square errors, standard deviations, and 95% confidence intervals of the predictions. Bayes factors are used for evaluating the probability distributions of the predictions, which are essential to structural condition assessments, such as outlier identification and reliability analysis. The performance of the present BDLM has been successfully verified based on the simulated data and the real data obtained from the structural health monitoring system installed on the revolving structure.

Reinforcement layout design for deep beam based on BESO of multi-level reinforcement diameter under discrete model

Hu-zhi Zhang,Peng Luo,Jian Yuan,Yao-sen Huang,Jia-dong Liu 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.4

By presetting various reinforcement diameters in topology optimization with the discrete model finite element analysis, an algorithm of bidirectional evolutionary structural optimization of multi-level reinforcement diameter is presented to obtain the optimal reinforcement topologies which describe the degree of stress of different parts. The results of a comparative study on different reinforcement feasible domain demonstrate that the more angle types of reinforcement are arranged in the initial domain, the higher utilization rate of reinforcement of the optimal topology becomes. According to the nonlinear finite element analysis of some deep beam examples, the ones designed with the optimization results have a certain advantage in ultimate bearing capacity, although their failure modes are greatly affected by the reinforcement feasible domain. Furthermore, the bearing capacity can be improved when constructional reinforcements are added in the subsequent design. However the adding would change the relative magnitude of the bearing capacity between the normal and inclined section, or the relative magnitude between the flexural and shear capacity within the inclined section, which affects the failure modes of components. Meanwhile, the adding would reduce the deformation capacity of the components as well. It is suggested that the inclined reinforcement and the constructional reinforcement should be added properly to ensure a desired ductile failure mode for components.

EA-D p45-IgG as a Potential Biomarker for Nasopharyngeal Carcinoma Diagnosis

Chen, Hao,Luo, Yao-Ling,Zhang, Lin,Tian, Li-Zhen,Feng, Zhi-Ting,Liu, Wan-Li Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Aim: To identify new biomarkers for NPC diagnosis with an anti-EBV Western blot test kit. Methods: Serum samples from 64 NPC patients and healthy subjects with four specific VCA-IgA/EA-IgA profiles were tested with an anti-EBV Western blot test kit from EUROIMMUN AG. Proteins were quantified with scores of intensity visually assigned to the protein bands. The markers which showed statistical differences between the NPC and non-NPC subjects were further evaluated in another 32 NPC patients and 32 controls in comparison with established biomarkers including VCA-IgA, EA-IgA, EBV-related protein IgG, and EBV DNA. Results: Among the markers screened, EA-D p45-IgG showed a statistically significant difference (p < 0.05) between NPC and non-NPC subjects with VCA-IgA positivy. In 32 VCA-IgA positive NPC patients and 32 control subjects, the diagnostic accuracy of EA-D p45-IgG was 78.1% with a positive predictive value of 77.8% and a negative predictive value of 78.6%. In the verification experiment, the specificity and sensitivity of EA-D p45-IgG were 75.0% and 90.6 %, respectively. Conclusions: EA-D p45-IgG might be a potential biomarker for NPC diagnosis, especially among VCA-IgA positive subjects.

On compressive behavior of large welded hollow spherical joints with both internal and external stiffeners

Tingting Shu,Xian Xu,Yao-Zhi Luo 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.2

Welded hollow spherical joints are commonly used joints in space grid structures. An internal stiffener is generally adopted to strengthen the joints when large hollow spheres are used. To further strengthen it, external stiffeners can be used at the same time. In this study, axial compression tests are conducted on four full-scale 550 mm spherical joints. The failure modes and strengths of the tested joints are investigated. It shows that the external stiffeners are able to increase the strength of the joint up to 25%. A numerical model for large spherical joints with stiffeners is established and verified against the experimental results. Parametric studies are executed considering six main design factors using the verified model. It is found that the strength of the spherical joint increases as the thickness, height and number of the external stiffeners increase, and the hollow sphere’s diameter has a neglectable effect on the enhancement caused by the external stiffeners. Based on the experimental and numerical results, a practical formula for the compressive bearing capacity of large welded hollow spherical joints with both internal and external stiffeners is proposed. The proposed formula gives a conservative prediction on the compressive capacity of large welded hollow spherical joints with both internal and external stiffeners.

Molecular Cloning and Expression of a Novel Protease-resistant GH-36 α-Galactosidase from Rhizopus sp. F78 ACCC 30795

Ya Nan Cao,Ya Ru Wang,Hui Ying Luo,Peng Jun Shi,Kun Meng,Zhi Gang Zhou,Zhi Fang Zhang,Bin Yao 한국미생물 · 생명공학회 2009 Journal of microbiology and biotechnology Vol.19 No.11

A Novel Two-Step Tensegrity Topology-Finding Method Based on Mixed Integer Programming and Nonlinear Programming

Xian Xu,Shaoxiong Huang,Tingting Shu,Yafeng Wang,Yao-Zhi Luo 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.4

A two-step topology-fi nding method based on mixed integer programming and nonlinear programming is proposed for tensegrity structures. In the fi rst step, feasible and symmetric strut connectivities are obtained through a ground structure method combined with mixed integer programming; in the second step, the cable connectivities are optimized through nonlinear programming to obtain a feasible tensegrity structure. The same ground structure used in the fi rst step is adopted in the second step, which is benefi cial to fi nd a more symmetric cable layout. The independent continuous mapping method is used in the second step to convert the 0–1 binary variables of cable connectivities to continuous variables to transform the combinatorial optimization problem into a nonlinear programming problem. The number of strut lengths is adopted as a control parameter and a symmetry objective function is proposed to generate a variety of regular and symmetric tensegrity structures. A multi-stage computation scheme is proposed to improve the computational effi ciency. Typical examples are carried out to validate the proposed method. The computational effi ciency of the method is benchmarked with existing methods fully based on mixed integer programming. Results demonstrate that the computational effi ciency of the proposed method is signifi cantly improved compared to the existing methods.

High-efficiency organic solar cells based on a small-molecule donor and a low-bandgap polymer acceptor with strong absorption

Yang, Yankang,Qiu, Beibei,Chen, Shanshan,Zhou, Qiuju,Peng, Ying,Zhang, Zhi-Guo,Yao, Jia,Luo, Zhenghui,Chen, Xiaofeng,Xue, Lingwei,Feng, Liuliu,Yang, Changduk,Li, Yongfang The Royal Society of Chemistry 2018 Journal of materials chemistry. A, Materials for e Vol.6 No.20

<P>Solution-processed organic solar cells (OSCs) have been attracting more and more attention for a series of well-known advantages, and power conversion efficiencies (PCEs) of over 11% have been reported. However, the highest PCE of the OSCs based on small molecule donor/polymer acceptor blends is only 4.82%, which was much lower than those of other types of OSCs due to weak absorption of the polymer acceptor and the unbalanced charge carrier mobility of the small molecule donor and the polymer acceptor. Here, we fabricated small molecule donor/polymer acceptor-based OSCs using the wide bandgap SM1 and DR3TBDTT as the small molecular donor and the low-bandgap n-type conjugated polymer PZ1 as the polymer acceptor. With the treatment of a solvent additive, which can promote the absorption intensity, enhance the carrier mobility and suppress the charge carrier recombination, the SM1-based devices and the DR3TBDTT-based devices show PCEs of 3.97% and 5.86%, respectively. It is worth mentioning that the PCE of 5.86% is the state-of-the-art efficiency for OSCs based on the small molecular donor/polymer acceptor system.</P>

Research on a New Class of Planar Tensegrity Trusses Consisting of Repetitive Units

Sili Li,Xian Xu,Jiaqi Tu,Yafeng Wang,Yao-Zhi Luo 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.5

Tensegrity structure is a prestressed self-equilibrated system consisting of compressed struts and tensioned cables. Planar truss is one of the most common forms of engineering structures with a wide application. This paper proposes a new class of planar tensegrity trusses whose prototype is unintentionally found by a topology optimization algorithm. The prototype truss is composed of two basic units which are combined alternately. In this paper, the state of prestress of the truss is analytically determined from the equilibrium conditions. The stiff ness and strength of the structure are analytically formulated by using the principle of virtual work. Parametric analysis of geometrical parameters on the stiff ness and strength of the structure is carried out. By changing the shape of the basic units, the uniform planar tensegrity truss is extended to a fi sh-bellied truss. Parametric analysis is also carried out for the fi sh-bellied truss. An example of extending the planar tensegrity truss into a three-dimensional latticed tensegrity truss is also given.