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Replacing fossil fuels with renewable energy is one of the important means to improve energy scarcity and environmental protection, and is of great significance for achieving sustainable development of human society. Vertical axis wind turbine (VAWT) is one of the key equipment for applying green energy — wind energy. During the operation of VAWT, its blades not only have to withstand periodic aerodynamic loads, but also suffer from centrifugal force effects and the Coriolis force effect caused by coupling with multi-dimensional deformation. The complex stress situation makes the blades susceptible to damage, resulting in structural resonance and instability of aeroelastic stability. This paper applies the Euler beam model and Hamilton principle to establish a nonlinear structural vibration motion equation for large-span vertical axis wind turbine blades with fully coupled four-dimensional deformation (i.e. lateral bending deformation, chord bending deformation, axial torsion deformation, and axial tensile deformation), and retains the nonlinear term of the motion equation to the third-order infinitesimal. Separating the motion equation into equilibrium equation and dynamic equation, it can be seen that the displacement of equilibrium state caused by the centrifugal force of the rigid body exists in the form of a coefficient in the dynamic equation, which will have an impact on the dynamic characteristics. This modeling work can provide a research foundation for exploring the dynamic characteristics and aeroelastic stability of VAWT blades in the future. [ABSTRACT FROM AUTHOR]

Water-quenching blast furnace slag as a by-product of the iron production has caused serious environmental concerns. This paper tried to investigate the feasibility of the blast furnace slag filler (WBFSF) used as an alternative filler to replace the limestone filler (LF) in asphalt mixtures. Specifically, the chemical compositions, morphology characteristics, phase distributions, and thermal properties of two fillers were studied; then rheological properties of asphalt mastics in four filler-asphalt ratios were further studied by the rotational viscosity, temperature sweep, temperature-frequency-sweep (T-f-sweep), and multiple stress creep recovery (MSCR) test. The results show that WBFSF has a larger specific surface area and better-developed mesopores compared with LF. WBFSF asphalt mastic presents a larger complex modulus and a smaller phase angle. Moreover, the MSCR results show that WBFSF improves the elastic recovery and rutting resistance of asphalt mastics. Therefore, WBFSF presents great potential to be used as an alternative filler in asphalt mixtures. Key words: WBFSF, asphalt mastic, rheological properties, high-temperature properties. Le laitier de haut fourneau par trempe a l'eau, qui est un sous-produit de la production de fer, a cause de graves problemes environnementaux. Ce document a tente d'etudier la faisabilite d'un produit de remplissage a base de laitier de haut fourneau par trempe a l'eau (RLHFTE) utilise comme remplissage pour remplacer les fines de calcaire (FC) dans les melanges d'asphalte. Plus precisement, les compositions chimiques, les caracteristiques morphologiques, les repartitions de phase et les proprietes thermiques de deux produits de remplissage ont ete etudiees, puis les proprietes rheologiques de mastics d'asphalte avec quatre rapports asphalte-produit de remplissage ont ete etudiees plus a fond par l'essai au viscosimetre rotatif, au balayage de temperature, au balayage de temperature-frequence et en recuperation de fluage de contrainte multiple (RFCM). Les resultats montrent que le RLHFTE a une surface specifique plus grande et des mesopores mieux developpees que les FC. Le mastic d'asphalte RLHFTE presente un plus grand module complexe et un plus petit angle de phase. De plus, les resultats de la RFCM montrent que le RLHFTE ameliore la recuperation elastique et la resistance a l'ornierage des mastics d'asphalte. Par consequent, le RLHFTE presente un grand potentiel d'utilisation comme produit de remplissage de remplacement dans les melanges d'asphalte. [Traduit par la Redaction] Mots-cles: produit de remplissage a base de laitier de haut fourneau par trempe a l'eau (RLHFTE), mastic d'asphalte, proprietes rheologiques, proprietes a haute temperature., Introduction Blast furnace slag is the by-products of the iron production process, and its output is approximately 300-700 kg/ton of pig iron (Gao et al. 2016). Since the initial temperature [...]

In this study, RuT400(σb ≥ 500 MPa) was milled with different cutting speeds, feeding rates and cutting depths to construct cutting force and surface roughness prediction models via response surface method (RSM). The milling parameters were optimised via response surface, contour map and iterative algorithm. The results show that that feeding rate and cutting depth are factors that significantly affect the cutting force. Similarly, cutting speed and feeding rate were found to be significant in regards to surface roughness. The multivariate linear equations yield more accurate surface roughness and cutting force predictions than fitting the linearised multivariate non-linear equations. The cutting force prediction model isF = 60.823 − 0.020V + 149.489f + 41.932a; the surface roughness prediction model isRa = 1.633 − 0.00161V + 1.803f + 0.0289a. The use of high-strength tools and a high-endurance manufacturing system for cutting force can greatly enhance the machining efficiency in a processing system with favourable rigidity. [ABSTRACT FROM AUTHOR]