Yuanjun Dai^1,2,*, Xin Wei¹, Baohua Li¹, Cong Wang¹, Kunju Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.2, pp. 337-348, 2024, DOI:10.32604/fdmp.2023.042434

Abstract To study the impact of the trailing-edge wear on the vibrational behavior of wind-turbine blades, unworn blades and trailing-edge worn blades have been assessed through relevant modal tests. According to these experiments, the natural frequencies of trailing-edge worn blades −1, −2, and −3 increase the most in the second to fourth order, the fifth order increases in the middle, and the first order increases the least. The damping ratio data indicate that, in general, the first five-order damping ratios of trailing-edge worn blades −1 and trailing-edge worn blades −2 are reduced, and the first five-order damping ratios of trailing-edge worn… More >

Yujie Huang¹, Hao Zhu², Dauletbek Assima⁴, Zheng Wang^1,*, Minmin Li³, Xinyue Zhao¹

Journal of Renewable Materials, Vol.9, No.4, pp. 829-840, 2021, DOI:10.32604/jrm.2021.014610

Abstract To improve the impact sound insulation performance of building floors and meet the objective requirements for living comfort of residents, in this article, three kinds of elastic cushion materials, Portuguese cork board, BGL insulation sound insulation foam board, and EPP polypropylene plastic foam board, are applied to the sound insulation of a light frame wood floor structure of the same bedroom and compared to the ordinary floor. This study uses the transfer function method and transient excitation method to measure the sound insulation, damping ratio, and elastic modulus of materials, as well as the sound insulation of the floor under… More >

Qian Wang^1,#,*, Zhaozhao Liu^1,2,#,*, Xiumei Zhong¹, Zhongnan Gao¹, Fuqiang Liu²

Journal of Renewable Materials, Vol.9, No.3, pp. 523-540, 2021, DOI:10.32604/jrm.2021.014114

Abstract To effectively improve the poor engineering properties of loess and enhance its seismic performance, the industrial by-product lignin is used as a modified material. Based on lots of dynamic triaxial tests, the dynamic elastic modulus and damping ratio of lignin-modified loess were tested. The effects of lignin content on the dynamic elastic modulus and damping ratio of lignin-modified loess were analyzed. Combined with scanning electron microscopy (SEM) and X-ray diffraction (XRD), the microscopic mechanism of lignin to improve the dynamic properties of loess was studied. The results show that lignin can effectively modify the dynamic deformation of loess under dynamic… More >