Improved Failure Mode Identification and Reliability Estimates for Electricity Transmission Towers

Studies on the theory of structural system reliability includes identification of main the failure modes and calculation of inclusive failure probabilities for the structural system. The efficient and accurate identification of failure modes in structural systems is difficult and represents a key focus for research in system reliability. The fundamental theory of the branch and bound algorithm for stage critical strength is reviewed in this paper. Some deficiencies in this method are highlighted. Corresponding approaches to overcome these deficiencies are proposed. Calculated system reliability solutions to the classical model, a truss with 10 elements, indicate that the improvement measures proposed in this paper increase the efficiency of recognising the main failure modes of the structural system, and are readily validated. The outcomes of this type of benchmark analysis suggest that the proposed methodology may be capable of representing a suitable basis for the structural system reliability analysis of complex truss-like structures, including transmission towers. Using the proposed approach, the principal failure modes and system reliability of a transmission tower are calculated. Based on practical engineering considerations, effective methods to improve this structural system reliability are proposed

Research on High Speed Cutting Parameter Optimization and Fault Diagnosis Technology

High speed cutting process is a very complicated process; cutting parameters have a significant effect on cutting process and play a key role in the process of product manufacturing. The overall scheme of high speed cutting parameter optimization and its fault diagnosis have been introduced. The mathematical model of the selected cutting parameters was established and the optimized parameters were obtained by combining the experimental design with the technology of data processing. The statistical description of high speed cutting process control was introduced and the fault diagnosis model of cutting parameter optimization by using the neural network was proposed. Finally, the mathematical model in the present study is validated with a numerical example. The results show that the present method solved the problem of poor universality of high speed cutting data effectively and avoided the inaccuracy of physical and chemical mechanism research. Meanwhile, the present study prevents the passive checks of the cutting and gets better diagnosis of the complicated cutting fault type

Absolute Distance Measurement Based on Self-Mixing Interferometry Using Compressed Sensing

An absolute distance measurement sensor based on self-mixing interferometry (SMI) is suitable for application in aerospace due to its small size and light weight. However, an SMI signal with a high sampling rate places a burden on sampling devices and other onboard sources. SMI distance measurement using compressed sensing (CS) is proposed in this work to relieve this burden. The SMI signal was sampled via a measurement matrix at a sampling rate lower than Nyquist’s law and then recovered by the greedy pursuit algorithm. The recovery algorithm was improved to increase its robustness and iteration speed. On a distance measuring system with a measurement error of 60 µm, the difference between raw data with 1800 points and CS recovered data with 300 points was within 0.15 µm, demonstrating the feasibility of SMI distance measurement using CS

Current situation and prospect of coal mine water treatment technology

Coal mine water is an important unconventional water source, and the resource utilization of mine water is of great significance in alleviating water scarcity and environmental protection in mining areas. This paper analyzed the source and water quality characteristics of mine water, and summarized the main treatment technologies of different types of mine water such as suspended solids, high salinity, acidity and special pollutants, as well as the characteristics and existing problems of each treatment technology. The majority of mine water contained a significant amount of suspended solids, with considerable fluctuations in both water quality and quantity. Efforts should be focused on enhancing the presettling capabilities of both underground water storage facilities and surface regulating reservoirs, developing and improving underground treatment technology for mining wells, and combining automation and intelligence to achieve unmanned operation. With the continuous increase of highly salinity mine water, its treatment technology had become a research focus in the field of mine water treatment. It was necessary to strengthen pretreatment, develop efficient technologies to remove silicon and hardness, introduce energy recovery devices, combine new and renewable energy to develop green and energy-saving coupling desalination technology, optimize the zero discharge process as a whole, and reduce the treatment cost of concentrated salt wastewater. Acidity and special pollution were currently the difficulties in mine water treatment, distributed and efficient directional processing technology should be adopted to explore the coupling processes and natural restoration governance. Guided by national policies, mining water treatment technology will develop towards being more energy-saving, highly effective, intelligent, and environmentally friendly

Hollow ZIF-67 derived porous cobalt sulfide as an efficient bifunctional electrocatalyst for overall water splitting

A hollow ZIF-67 templating approach was used to fabricate a hollow cobalt sulfide superstructure with enhanced activity for overall water splitting.</jats:p

The Influence of Tool Rake Surface Geometry on the Hard Turning Process of AISI52100 Hardened Steel

The hard turning process has been widely used in the field of hard material precision machining because of its high efficiency, low processing residual stress, and low environmental pollution. Due to its undesirably processing quality, it is still not a substitute for traditional grinding, so many studies have reported that the process has been optimized. However, there has been little research on the geometry optimization of hard cutting tools, which have a great influence on the traditional machining process. In this paper, two tools with different rake face shapes are designed. The finite element analysis method is used to compare their performance with a conventional plane tool while turning hardened steel. The results show that the cutting performance of the designed tool T1 and T2 (chip morphology, cutting force, and cutting temperature) and the quality of the machined surface are improved compared with the tool. The cutting force decreased by 12.72% and 14.74%, the cutting temperature decreased by 7.56% and 9.01%, respectively, and the surface residual stress decreased by 26.56% and 28.66%.</jats:p

Development of the CEPC booster prototype dipole magnets

The CEPC booster will accelerate the [Formula: see text] beam from 10 GeV to 120 GeV, so the field of the dipole magnets will change with the beam energy, of which the minimal working field is 29 Gs whereas the maximal field is 338 Gs. To reach the requirement of high precision at lower field level, three kinds of new dipole magnets are proposed and studied. To test and verify the designs of the magnets, two subscale prototype magnets are fabricated. </jats:p