On the Collapse Resistance of the Levy Type and the Loop-Free Suspen-Dome Structures After Accidental Failure of Cables

Renjie Liu,Yao Zou,Guangyong Wang,Suduo Xue 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.2

Current Levy type suspen-domes use loop cables which are key elements and carry large tensions. The loop-free suspendome was proposed for improving the collapse resistance and reducing cable tensions. However, the collapse resistance of the loop-free suspen-dome after accidental failure of cables has not been verifi ed and its key element is not clear. In this paper, analysis on the collapse resistance of both the Levy type suspen-dome and the loop-free suspen-dome after accidental failure of cables is performed based on the AP method by considering dynamic eff ect and non-linearity. The displacements and residual bearing capacity of 34 cable-rupture schemes are discussed, the eff ect on the cable tension and failure mode are also analyzed. It turns out that collapse resistance of the loop-free suspen-dome is better than the Levy type suspen-dome. The failure of cables does not infl uence the tension of remaining cables obviously so that the loop-free cable-strut system has suffi cient stiff ness and provides support and restraint for the reticulated shell. The most important cable in the loop-free suspen-dome is located in the outermost layer of the cable-strut system. It is also found that whether progressive collapse of the suspen-dome occurs after accidental failure of cables depends on both the bearing capacity of the reticulated shell and the residual contribution of the cable-strut system.

Experimental Investigation of Output Current Variation in Biased Silicon-based Quadrant Photodetector

Hongxu Liu,Di Wang,Chenang Li,Guangyong Jin 한국광학회 2020 Current Optics and Photonics Vol.4 No.4

We report on the relationship between output current for quadrant photodetector (QPD) and bias voltage in silicon-based p-i-n (positive-intrinsic-negative) QPD examined using millisecond pulse laser (ms pulse laser) irradiation. The mechanism governing the relationship was further studied experimentally. The output current curves were obtained by carrying out QPD under different bias voltages (0~40 V) irradiated by ms pulse laser. Compared to other photodetectors, the relaxation was created in the output current for QPD which is never present in other photodetectors, such as PIN and avalanche photodetector (APD), and the maximum value of relaxation was from 6.8 to 38.0 µA, the amplitude of relaxation increases with bias value. The mechanism behind this relaxation phenomenon can be ascribed to the bias voltage induced Joule heating effect. With bias voltage increasing, the temperature in a QPD device will increase accordingly, which makes carriers in a QPD move more dramatically, and thus leads to the formation of such relaxation.

On the plane geometry design method of the loop-free hyperbolic single-layer cable structures

Renjie Liu,Jiajia Cao,Hang Zhao,Su-Duo Xue,Guangyong Wang,Jin Liang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

The plane geometry design of the cable-net structure is the basis for the form-finding and structural design. The loop-free single-layer cable-net structure is a new cable-net scheme, but due to its special and complex shape, it is difficult to determine its plane geometry according to architectural requirements. In this paper, the moving support node method is proposed, which can quickly get the plane geometry of a loop-free single-layer cable-net structure. The form-finding is proceeded based on the existing small elastic modulus method. There are two constraints when using the moving support node method. One is that the projection of all cables is straight line, and the other is that the distance between the two cables of each support node and the inner boundary of the target is equal. The aim is to minimize the sum of the distances from all cables to the inner boundary of the target. Using the plane geometry control parameters and the plane coordinates of the support nodes as decision variables, the plane geometry closest to the target inner and outer boundaries is get through optimization analysis. According to the derivation of the formula, the plane projection shape of a loop-free single-layer cable-net structure is mainly related to three parameters, including the number of supports, the difference between the node numbers of the supports at both ends of each cable, and the target curve equations of the inner and outer boundaries. Finally, taking the roof structure of Linyi Olympic Stadium as an instance, the feasibility of the plane geometry design method of the loop-free single-layer cable-net structures based on the moving support node method is verified.

Combining Ultrasound-Mediated Intracellular Delivery with Microfluidics in Various Applications

Huang Guangyong,Lin Lin,Wu Shixiong,Dang Haojie,Cheng Xuesong,Liu Ying,You Hui 한국바이오칩학회 2024 BioChip Journal Vol.18 No.1

Ultrasound-mediated intracellular delivery is one of the popular technologies based on membrane rupture at present. To date, ultrasound directly acts on a large number of cells to achieve cargo delivery and has been widely used in drug deliv-ery, disease therapy and other fields. However, the existing macroscopic methods can no longer meet the requirements of accurate tracking and analysis and are prone to extensive cell damage and even death. With the rapid advancements in microfl uidic technologies, the combination of ultrasound and microfluidics (CUM) technology can effectively improve the delivery efficiency and cell survival rates. This new technology has rapidly become a new direction and focus of research. Thus, we analysed the mechanism of sonoporation and the effect of acoustic waves in a microfluidic channel. In addition, we reviewed the application of these new technologies in terms of structure and fabrication of ultrasound transducers and microfl uidic devices. As regards our main objective, we hope to help researchers better understand the future developments and the challenges of new technologies. With this review, researchers can promote the development of new technologies to solve the current challenges of intracellular delivery and advance clinical applications.

Interface damage mechanism of rubber cord composite material

Xiaohui Guo,Xiaojing Yuan,Guangyong Liu,Hefang Qiu,Fanfan Cui 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.1

In order to study the interface failure mechanism of rubber cord composites laid at symmetrical angles, a representativevolume element was established by the finite element method to simulate the stress distribution at the mesoscopic level ofrubber cord composites. The energy-based power law is used to simulate the damage evolution of the cord-rubber interface. The results show that the interface damage is caused by the torque that the cord bears during the stretching process, and theinterface assumes the role of transmitting torque in this process, so the failure occurred.The initial interface stiffness is a vitalbonding interface parameter that affects the interface damage evolution, and the initial stiffness is positively correlated withthe interface damage evolution variable. The increase in the included angle of the cord will cause the torque on the cord toincrease, resulting in aggravated interface failure.

Application of Three-Dimensional Solubility Parameter in Diffusion Behavior of Rubber-Solvent System and Its Predictive Power in Calculating the Key Parameters

Xingwang Jiang,Yupeng Hao,Huiyu Wang,Jieyun Tu,Guangyong Liu 한국고분자학회 2022 Macromolecular Research Vol.30 No.4

Three different rubbers, hydrogenated nitrile butadiene rubber (HNBR), ethylene vinyl acetate copolymer (EVM) and ethylene propylene diene rubber (EPDM), and two blends, HNBR/EVM and HNBR/EPDM were compounded both with and without fillers, and were vulcanized with the same peroxide curing system. Peppas- Sahlin model was used to explain the diffusion mechanism of solvents in rubber vulcanizates. Transport parameters including diffusion coefficient, sorption coefficient and permeation coefficient were calculated and correlated with Flory-Huggins interaction parameters (χ). The Peppas-Sahlin model dealing with diffusion behaviors of solvents shows high degree of fitting for both unfilled and filled rubber-solvent systems. With the addition of carbon black, the diffusion coefficient increases while the sorption and permeation coefficients decrease. The sorption coefficient increases linearly with the permeation coefficient. New Flory-Huggins interaction parameter (χN) calculated by threedimensional solubility parameters shows better predictive power in diffusion behaviors than the traditional one (χT). By mathematical fitting, a linear relationship can be obtained between the maximum swelling ratio and χN, while an exponential relationship is gained for the permeation coefficient. The discovery of this rule connects three-dimensional solubility parameters with the swelling of polymer in solvent, which provides experimental basis for the further study of the medium resistance of polymer.