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Optimization of gear teeth in the wind turbine drive train with gear contact’s uncertainty using the reliability-based design optimization

Lee Changwoo, Park Yonghui

Archive of Mechanical Engineering

2022

LXIX, nr 4

713--728

Although gear teeth give lots of advantages, there is a high possibility of failure in gear teeth in each gear stage in the drive train system. In this research, the authors developed proper gear teeth using the basic theorem of gear failure and reliability-based design optimization. A design variable characterized by a probability distribution was applied to the static stress analysis model and the dynamics analysis model to determine an objective function and constraint equations and to solve the reliability-based design optimization. For the optimization, the authors simulated the torsional drive train system which includes rotational coordinates. First, the authors established a static stress analysis model which gives information about endurance limit and bending strength. By expressing gear mesh stiffness in terms of the Fourier series, the equations of motion including the gear mesh models and kinematical relations in the drive train system were acquired in the form of the Lagrange equations and constraint equations. For the numerical analysis, the Newmark Beta method was used to get dynamic responses including gear mesh contact forces. From the results such as the gear mesh contact force, the authors calculated the probability of failure, arranged each probability and gear teeth, and proposed a reasonable and economic design of gear teeth.

Use of Unmanned Aerial Vehicles for 3D topographic Mapping and Monitoring the Air Quality of Open-pit Mines

Bui Xuan‑Nam, Lee Changwoo, Nguyen Quoc Long, Adeel Ahmad, Cao Xuan Cuong, Nguyen Viet Nghia, Le Van Canh, Nguyen Hoang, Le Qui Thao, Duong Thuy Huong, Nguyen Van Duc

Inżynieria Mineralna

2019

R. 21, nr 2/2

223--239

Recently remarkable advancement development of unmanned aerial vehicles (UAVs) has been observed and their applications have been shown in many fields such as agriculture, industry, and environmental management. However, in the mining industry, the application of UAV technology remains potential. This paper presents a low-cost unmanned aerial vehicle technology-based system for 3D mapping and air quality monitoring at open-pit mine sites in Vietnam. The system includes several dust sensors that are mounted on a low-cost rotary-wing type UAV. The system collects a variety of data, mainly images and airborne pollutant concentrations. To evaluate the performance of the proposed system, field tests were carried out at the Coc Sau coal mine. Based on the images transmitted to the ground monitoring station, large scale 3D topographic maps were successfully modeled. In addition, sensors mounted on the UAV system were able to monitor the levels of environmental variables associated with the air quality within the pit such as temperature, dust, CO, CO2, and NOx. The field test results in this study illustrate the applicability of the low-cost UAV for the 3D mapping and the air quality monitoring at large and deep coal pits with relatively high accuracy.