Study on Wear Prediction of Shield Disc Cutter in Hard Rock and Its Application

Zhenyong Wang,Chenglong Liu,Yusheng Jiang,Linwei Dong,Shixian Wang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.3

It is important to enable the prediction of disc cutter wear during shield tunnelling through hard rock because such wear is associated with project delays and increased costs. Based on a theoretical analysis of Archard’s wear mechanism and Euler’s rotation theorem, a displacement equation of rock-breaking point A on the disc cutter ring is studied, and then a new wear prediction model is established combined with the theoretical analysis of the disc cutter force and wear test. The cutter wear prediction model is verified by using the data of two cases, and the results reveal that the errors between measured and predicted values are less than 25%. The research results also show that abrasive wear is the main wear mechanism (approximately 88%). In addition, the influence of fatigue wear is very small, accounting for only approximately 2%, which can be ignored. Finally, the maximum tunneling distance of disc cutters under different installation radii and penetration is studied using the model, and the results can be used as references for optimizing shield tunneling parameters and predicting the disc cutter replacement time.

Effects of chelated Zn/Cu/Mn on redox status, immune responses and hoof health in lactating Holstein cows

Xue-Jun Zhao,Zhong-Peng Li,Jun-Hong Wang,Xiang-Ming Xing,Zhenyong Wang,Lin Wang,Zhong-Hua Wang 대한수의학회 2015 Journal of Veterinary Science Vol.16 No.4

To evaluate the effects of chelated Zn/Cu/Mn on redox status, immune responses and hoof health in lactating Holstein cows, 48 head in early lactation were divided into healthy or lame groups according to their gait score. Cows were fed the same amount of Zn/Cu/Mn as sulfate salts or in chelated forms for 180 days, and foot-and-mouth disease (FMD) vaccine was injected at day 90. The results showed that lame cows had lower antioxidant function, serum Zn/Mn levels, hair Cu levels, and hoof hardness. Moreover, increased antioxidant status, FMD antibody titers, serum and hair levels of Zn/Cu/Mn, and hoof hardness and decreased milk fat percent and arthritis biomarkers were observed in cows fed chelated Zn/Cu/Mn. In summary, supplementation with chelated Zn/Cu/Mn improved antioxidant status and immune responses, reduced arthritis biomarkers, and increased accumulation of Zn/Cu/Mn in the body and hoof hardness in dairy cows.

An extremum method for bending-wrinkling predictions of inflated conical cantilever beam

Wang, Changguo,Du, Zhenyong,Tan, Huifeng Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.46 No.1

An extremum method is presented to predict the wrinkling characteristics of the inflated cone in bending. The wrinkling factor is firstly defined so as to obtain the wrinkling condition. The initial wrinkling location is then determined by searching the maximum of the wrinkling factor. The critical wrinkling load is finally obtained by determining the ratio of the wrinkling moment versus the initial wrinkling location. The extremum method is proposed based on the assumption of membrane material of beam wall, and it is extended to consider beam wall with thin-shell material in the end. The nondimensional analyses show that the initial wrinkling location is closely related to the taper ratio. When the taper ratio is higher than the critical value, the initial wrinkles will be initiated at a different location. The nondimensional critical wrinkling load nonlinearly increases as the taper ratio increases firstly, and then linearly increases after the critical taper ratio. The critical taper ratio reflects the highest load-carrying efficiency of the inflated cone in bending, and it can be regarded as a measure to optimize the geometry of the inflated cone. The comparative analysis shows fairly good agreement between analytical and numerical results. Over the whole range of the comparison, the mean differences are lower than 3%. This gives confidence to use extremum method for bending-wrinkling analysis of inflated conical cantilever beam.

Wiretapping Strategies for Artificial Noise Assisted Communication in MU-MIMO wiretap channel

( Shu Wang ),( Xinyu Da ),( Zhenyong Chu ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.5

We investigate the opposite of artificial noise (AN)-assisted communication in multiple-input-multiple-output (MIMO) wiretap channels for the multiuser case by taking the side of the eavesdropper. We first define a framework for an AN-assisted multiuser multiple-input-multiple-output (MU-MIMO) system, for which eavesdropping methods are proposed with and without knowledge of legitimate users` channel state information (CSI). The proposed method without CSI is based on a modified joint approximate diagonalization of eigen-matrices algorithm, which eliminates permutation indetermination and phase ambiguity, as well as the minimum description length algorithm, which blindly estimates the number of secret data sources. Simulation results show that both proposed methods can intercept information effectively. In addition, the proposed method without legitimate users` CSI performs well in terms of robustness and computational complexity.

An extremum method for bending-wrinkling predictions of inflated conical cantilever beam

Changguo Wang,Zhenyong Du,Huifeng Tan 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.46 No.1

An extremum method is presented to predict the wrinkling characteristics of the inflated cone in bending. The wrinkling factor is firstly defined so as to obtain the wrinkling condition. The initial wrinkling location is then determined by searching the maximum of the wrinkling factor. The critical wrinkling load is finally obtained by determining the ratio of the wrinkling moment versus the initial wrinkling location. The extremum method is proposed based on the assumption of membrane material of beam wall, and it is extended to consider beam wall with thin-shell material in the end. The nondimensional analyses show that the initial wrinkling location is closely related to the taper ratio. When the taper ratio is higher than the critical value, the initial wrinkles will be initiated at a different location. The nondimensional critical wrinkling load nonlinearly increases as the taper ratio increases firstly, and then linearly increases after the critical taper ratio. The critical taper ratio reflects the highest load-carrying efficiency of the inflated cone in bending, and it can be regarded as a measure to optimize the geometry of the inflated cone. The comparative analysis shows fairly good agreement between analytical and numerical results. Over the whole range of the comparison, the mean differences are lower than 3%. This gives confidence to use extremum method for bending-wrinkling analysis of inflated conical cantilever beam.

Treatment of Mycoplasma wenyonii Infection in Cows with Imidocarb Dipropionate Injection-acupuncture

Jianzhu Liu,Zhengui Yan,Tiantian Chen,Ziqiang Cheng,Huijun Guo,Zhenyong Wang,Yong Wang 사단법인약침학회 2008 Journal of Acupuncture & Meridian Studies Vol.1 No.2

Sixteen shorthorn cows from Xiazhuang farm were admitted to the Veterinary Teaching Hospital at the College of Animal Science and Veterinary Medicine, Shandong Agricultural University for evaluation of poor appetite, listlessness, fever, tachycardia, tachypnea, lethargy, positive jugular venous pulse and anemia. Blood smear examination and polymerase chain reaction analysis in these cows revealed an infection with Mycoplasma wenyonii. The subjects were divided into two groups: control group (three cows) treated with intramuscular injection with imidocarb dipropionate (3 mg/kg/day for 2 days) and the experimental group (13 cows), treated with injection-acupuncture (Imidocarb Dipropionate, 1 mg/kg, once every 3 days for 6 days) at BL17, BL18, BL20, BL25, ST36, SP06 and CV04. At day 15, negative results were found using blood smear examination in all control and experimental groups. Sixteen shorthorn cows from Xiazhuang farm were admitted to the Veterinary Teaching Hospital at the College of Animal Science and Veterinary Medicine, Shandong Agricultural University for evaluation of poor appetite, listlessness, fever, tachycardia, tachypnea, lethargy, positive jugular venous pulse and anemia. Blood smear examination and polymerase chain reaction analysis in these cows revealed an infection with Mycoplasma wenyonii. The subjects were divided into two groups: control group (three cows) treated with intramuscular injection with imidocarb dipropionate (3 mg/kg/day for 2 days) and the experimental group (13 cows), treated with injection-acupuncture (Imidocarb Dipropionate, 1 mg/kg, once every 3 days for 6 days) at BL17, BL18, BL20, BL25, ST36, SP06 and CV04. At day 15, negative results were found using blood smear examination in all control and experimental groups.