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Motor Frame Design
Published in Wei Tong, Mechanical Design and Manufacturing of Electric Motors, 2022
Steel casting is a specialized form of casting, adapted for parts that must withstand heavy loads and shocks. There are generally two types of steel castings to meet different needs of various applications: carbon steel casting and alloy steel casting. Carbon steel casting is the most popular type, which uses low-, medium-, and high-carbon steel in casting to obtain different ranges of strength. For alloy steel castings, special alloy elements (e.g., manganese and chromium) are added to casting steels to enhance the desirable material properties. Among alloy steel castings, stainless steel casting is designed to resist corrosion and thus widely used in the chemical, shipbuilding, and renewable energy industries. However, steel casting is seldom used for making motor components unless casting iron cannot deliver enough strength or motors have strict anticorrosion requirements.
Bi-objective optimization using an improved NSGA-II for energy-efficient scheduling of a distributed assembly blocking flowshop
Published in Engineering Optimization, 2023
Wei Niu, Jun-qing Li, Hui Jin, Rui Qi, Hong-yan Sang
A blocking constraint means that there is no buffer between two consecutive operations. Blocking FlowShoP (FSP) scheduling has been verified to be an NP-hard problem (Grabowski and Pempera 2007). The FSP assumes an infinite buffer exists between machines. However, due to space constraints in practical applications such as steel casting and food processing there is frequently no buffer available. Therefore, traditional flowshop scheduling cannot be directly applied in actual industrial production. Furthermore, as globalization progresses, the traditional single factory model of centralized production can no longer adapt to competition and meet customer needs, resulting in the emergence of a Distributed FlowShoP (DFSP) scheduling production mode, which reduces production costs. A DFSP that also incorporates an assembly stage is known as Distributed Assembly FlowShoP (DAFSP) scheduling (Chung-Yee Lee, T.C.E. Cheng, and Bertrand Miao Tsong Lin 1993; Quan-Ke Pan et al. 2019; Wu et al. 2021). A number of practical industrial scheduling processes require processing energy consumption and standby energy consumption to maximize the benefits of green energy-saving scheduling.
Experimental Study of UHPC-RC Composite Pile Connected by Shear Keys
Published in Structural Engineering International, 2022
Yongtao Zhang, Hehui Zheng, Gang Li
A sea-crossing bridge was taken as an example. The pile foundation of the approach span is located in the coral reef stratum, using cast-in-place piles with a diameter of 2 m and a length of 27 m. The steel casting has a thickness of 100 mm as shown in Fig. 22a. The top end of the pile is located 2 m below the seabed surface. And the vertical reaction force and bending moment under the most unfavorable loading are 14 080 and 2048 kN*m, respectively. Then, the composite pile is used to replace the original one. The upper pipe pile and lower pile use U100 and C50 respectively. The outer diameter and wall thickness of the pipe pile is 1.8 and 0.15 m respectively. After a trial calculation, the length of the UHPC pile and the RC pile is determined to be 10 and 15 m respectively as shown in Fig. 22b. The axial compressive capacity and cracking strength of the composite pile are 24 429 and 4765 kN*m respectively.
Evolution of solidification structure, primary phase and wear properties of Sn–11wt%Sb alloy ingots under permanent magnet stirring
Published in Philosophical Magazine, 2021
Wanlin Wang, Jianfei Peng, Jie Zeng, Chenyang Zhu, Yindong Yang, Alex McLean
Rather than using conventional EMS, permanent magnet stirring (PMS), based on the use of sintered NdFeB material with excellent magnetic characteristics, is a new choice to generate a magnetic field for the stirring of liquid metal during solidification. Recent experience with steel casting indicates that PMS requires <20 pct. of the total energy compared with EMS [14]. Despite the excellent magnetic density properties, low power consumption and avoiding coil corrosion by cooling water, this relatively new technology has received comparatively little attention by the metal casting community [15–20]. In 1992, Vives [16] first utilised this method in control of solidification structures of Al–4wt%Cu and Al–7wt%Si and found it possible to refine the alloy structure by the production of intense 3D multiphase flows in solidifying semisolid alloy slurries. Since then, PMS has been mainly used to control the solidification structure of metal alloys, such as Sn–Bi [17], Sn–Pb [18], Al–Cu [19] and Al–Si [20]. The introduction of a rotary magnetic field (RMF) during the solidification process can generate a swirling flow [21]. An increase in the magnetic field accelerates the swirling flow and produces efficient melt mixing. RMF-driven metal flow can improve the heat, mass and solute transport during solidification, and is conducive to the evolution of a more satisfactory solidification structure and hence improve material performance of alloys [22].