Numerical analysis on tensile properties of composite hybrid bonded/bolted joints with flanging

Xiaoquan Cheng,Jie Zhang,Jikui Zhang,Peng Liu,Yujia Cheng,Yahong Xu 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.26 No.3

A detailed study was carried out on the tensile properties of the single-lap joint of a steel panel bolted/bonded to a composite laminate with a flanging. Finite element model (FEM) was established to predict the strength and to analyze the damage propagation of the hybrid joints by ABAQUS/Standard, which especially adopted cohesive elements to simulate the interface between the laminate and adhesive. The strength and failure mode predicted by FEM were in good agreement with the experimental results. In addition, three influence factors including adhesive thickness, bolt preload and bolt-hole clearance were studied. The results show that the three parameters have effect on the first drop load of the load-displacement curve, but the effect of bolt-hole clearance is the largest. The bolt-hole clearance should be avoided for hybrid joints.

Effect of curing condition on mechanical properties of scarf-repaired composite laminates

Xiaoquan Cheng,Jie Zhang,Yujia Cheng,Xin Guo,Wenjun Huang 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.37 No.4

Composite structures are generally pressurized at both sides when repaired by the scarf repair method. But single-face vacuum bag curing (SVC) may be used in some practical scarf repair of penetration damage due to the low accessibility of composite structures, which can decrease bonding quality and may reduce structural mechanical properties. In this paper, experimental investigations were conducted on tensile and compressive properties of scarf-repaired composite laminates using SVC and double-face vacuum bag curing (DVC) in four hygrothermal environments. Finite element models of composite scarf joints with voids were established to further explore the failure mechanism of scarf-repaired laminates. Results show that the curing condition hardly affects tensile and compressive properties of the repaired laminates though it significantly affects the bonding quality with adhesive inner voids. Failure loads of scarf joints almost keep unchanged with adhesive voids increasing.

Prediction of heavy metal bioavailability in soil by rhizosphere-based method

Shuzhen Zhang,Xiaoquan Shan 환경독성보건학회 2004 한국독성학회 심포지움 및 학술발표회 Vol.- No.-

Microwave heating assisted synthesis of novel SnSe/g-C3N4 composites for effective photocatalytic H2 production

Pengfei Chen,Xiaoquan Dai,Pingxing Xing,Xinyue Zhao,Qingle Zhang,Shifeng Ge,Jianxiao Si,Leihong Zhao,Yiming He 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

Novel SnSe/g-C3N4 photocatalysts were one-step synthesized via a microwave heating assisted process in35 min with SnSe and melamine as precursors. The as-synthesized SnSe/g-C3N4 worked very well in H2evolution via photocatalysis. Under simulated sunlight, the best SnSe/g-C3N4 sample displayed a H2-production velocity of 1064 mmol g 1 h 1, which is 1.8 folds faster than that of neat g-C3N4. Similarpromotion effect was also observed under visible light. To reveal the nature behind the highphotoactivity, a thorough investigation was performed. XRD and XPS experiments proved the binaryconstitution of the composite. DRS experiment demonstrated that the addition of SnSe improved thephotoabsorption performance. N2-adsorption analysis showed that the SnSe/g-C3N4 photocatalystpresented similar surface area as g-C3N4. TEM experiments showed that some bulk SnSe werespontaneously decomposed to nanoparticles andfinely dispersed in g-C3N4 during the microwaveheating process. These SnSe nanoparticles were believed to be the active phase and constructed aheterojunction structure with g-C3N4, resulting in the enhanced charge separation. This conclusion wasconsidered as the key factor leading to the high H2-evolution performance and was further confirmed bythe PL, EIS, and PC experiments. The present work provides a feasible and rapid method for theconstruction of g-C3N4 based photocatalysts.

Buckling and post-buckling behaviors of 1/3 composite cylindrical shell with an opening

Yihao Ma,Xiaoquan Cheng,Zhaodi Wang,Xin Guo,Jie Zhang,Yahong Xu 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.27 No.5

A 1/3 composite cylindrical shell with a central rectangular opening was axially compressed experimentally, and its critical buckling load and displacement, and strains were measured. A finite element model (FEM) of the shell with Hashin failure criteria was established to analyze its buckling and post-buckling behaviors by nonlinear Newton-Raphson method. The geometric imperfection sensitivity and the effect of side supported conditions of the shell were investigated. It was found that the Newton-Raphson method can be used to analyze the buckling and post-buckling behaviors of the shell. The shell is not sensitive to initial geometric imperfection. And the support design of the shell by side stiffeners is a good way to obtain the critical buckling load and simplify the experimental fixture.

Elevated level of renal xanthine oxidase mRNA transcription after nephropathogenic infectious bronchitis virus infection in growing layers

Huayuan Lin,Qiqi Huang,Xiaoquan Guo,Ping Liu,Weilian Liu,Yuelong Zou,Shuliang Zhu,Guangfu Deng,Jun Kuang,Caiying Zhang,Huabin Cao,Guoliang Hu 대한수의학회 2015 Journal of Veterinary Science Vol.16 No.4

To assess relationships between xanthine oxidase (XOD) and nephropathogenic infectious bronchitis virus (NIBV) infection, 240 growing layers (35 days old) were randomly divided into two groups (infected and control) of 120 chickens each. Each chicken in the control and infected group was intranasally inoculated with 0.2 mL sterile physiological saline and virus, respectively, after which serum antioxidant parameters and renal XOD mRNA expression in growing layers were evaluated at 8, 15 and 22 days post-inoculation (dpi). The results showed that serum glutathione peroxidase and superoxide dismutase activities in the infected group were significantly lower than in the control group at 8 and 15 dpi (p < 0.01), while serum malondialdehyde concentrations were significantly higher (p < 0.01). The serum uric acid was significantly higher than that of the control group at 15 dpi (p < 0.01). In addition, the kidney mRNA transcript level and serum activity of XOD in the infected group was significantly higher than that of the control group at 8, 15 and 22 dpi (p < 0.05). The results indicated that NIBV infection could cause the increases of renal XOD gene transcription and serum XOD activity, leading to hyperuricemia and reduction of antioxidants in the body.

Nonlinear optical properties of silver colloidal solution by in situ synthesis technique

Yan Deng,Youyi Sun,Pei Wang,Douguo Zhang,Xiaojin Jiao,Hai Ming,Qijing Zhang,Yang Jiao,Xiaoquan Sun 한국물리학회 2008 Current Applied Physics Vol.8 No.1

The silver colloidal solutions were prepared by in situ synthesis technique in the presence of the Polymethyl Methacrylate, which was polymerized by reversible addition-fragmentation transfer. The UV–VIS spectra and transmission electron microscopy had shown the formation of sphere silver nanoparticles with average size of 10 nm. Nonlinear optical properties as a function of silver concentration were studied using Z-scan technique with 13 ns pulse duration at 532 nm. The optical nonlinearity enhancement was observed by increasing the concentration. The third-order nonlinear susceptibility v(3) was measured to 1.045 · 1011 esu when the concentration was 2.13 mg/ml. Besides, the sample was founded to exhibit a shift from saturable absorption to reverse saturable absorption at higher incident laser energy. The reverse saturable absorption was observed to be responsible for the optical limiting characteristics in our experiments. 2007 Published by Elsevier B.V. The silver colloidal solutions were prepared by in situ synthesis technique in the presence of the Polymethyl Methacrylate, which was polymerized by reversible addition-fragmentation transfer. The UV–VIS spectra and transmission electron microscopy had shown the formation of sphere silver nanoparticles with average size of 10 nm. Nonlinear optical properties as a function of silver concentration were studied using Z-scan technique with 13 ns pulse duration at 532 nm. The optical nonlinearity enhancement was observed by increasing the concentration. The third-order nonlinear susceptibility v(3) was measured to 1.045 · 1011 esu when the concentration was 2.13 mg/ml. Besides, the sample was founded to exhibit a shift from saturable absorption to reverse saturable absorption at higher incident laser energy. The reverse saturable absorption was observed to be responsible for the optical limiting characteristics in our experiments. 2007 Published by Elsevier B.V.

Analysis of Laser-protection Performance of Asymmetric-phase-mask Wavefront-coding Imaging Systems

Yangliang Li,Qing Ye,Lei Wang,Hao Zhang,Yunlong Wu,Xian’an Dou,Xiaoquan Sun 한국광학회 2023 Current Optics and Photonics Vol.7 No.1

Fatty Acid-Binding Protein 4 in Patients with and without Diabetic Retinopathy

Ping Huang,Xiaoqin Zhao,Yi Sun,Xinlei Wang,Rong Ouyang,Yanqiu Jiang,Xiaoquan Zhang,Renyue Hu,Zhuqi Tang,Yunjuan Gu 대한당뇨병학회 2022 Diabetes and Metabolism Journal Vol.46 No.4

Background: Fatty acid-binding protein 4 (FABP4) has been demonstrated to be a predictor of early diabetic nephropathy. However, little is known about the relationship between FABP4 and diabetic retinopathy (DR). This study explored the value of FABP4 as a biomarker of DR in patients with type 2 diabetes mellitus (T2DM).Methods: A total of 238 subjects were enrolled, including 20 healthy controls and 218 T2DM patients. Serum FABP4 levels were measured using a sandwich enzyme-linked immunosorbent assay. The grade of DR was determined using fundus fluorescence angiography. Based on the international classification of DR, all T2DM patients were classified into the following three subgroups: non-DR group, non-proliferative diabetic retinopathy (NPDR) group, and proliferative diabetic retinopathy (PDR) group. Multivariate logistic regression analyses were employed to assess the correlation between FABP4 levels and DR severity.Results: FABP4 correlated positively with DR severity (<i>r</i>=0.225, <i>P</i>=0.001). Receiver operating characteristic curve analysis was used to assess the diagnostic potential of FABP4 in identifying DR, with an area under the curve of 0.624 (37% sensitivity, 83.6% specificity) and an optimum cut-off value of 76.4 μg/L. Multivariate logistic regression model including FABP4 as a categorized binary variable using the cut-off value of 76.4 μg/L showed that the concentration of FABP4 above the cut-off value increased the risk of NPDR (odds ratio [OR], 3.231; 95% confidence interval [CI], 1.574 to 6.632; <i>P</i>=0.001) and PDR (OR, 3.689; 95% CI, 1.306 to 10.424; <i>P</i>=0.014).Conclusion: FABP4 may be used as a serum biomarker for the diagnosis of DR.