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关键词： Stiffness matrix  

摘要： The sensitivity analysis of structural Vibration modes (eigenvalues and eigenvectors) is widely used in structural Vibration control, optimal design and damage identification. At present, the main modal sensitivity analysis algorithms are modal superposition method, Nelson' s method and their improved algorithms. When these algorithms are applied to modal sensitivity analysis of large-scale engineering structures, there is generally a defect of low computational efficiency. In order to save the calculation cost, an improved subspace iteration method for modal sensitivity analysis was proposed based on approximate flexibility. Firstly, the calculation problem of modal sensitivity was transformed into the calculation problem of modal eigen-pairs after minor modification of the structure by difference Operation. Then, an approximate flexibility calculation formula was proposed to quickly estimate the inverse of the modified stiffness matrix of the structure, which was applied to the subspace iteration process to quickly obtain the modal eigen-pairs after minor modification, and accordingly the corresponding modal sensitivity could be quickly calculated. Two structural models were taken as examples to verify the proposed method. The results show that the calculation accuracy of the proposed method is basically consistent with that of the existing modal sensitivity algorithm, but the calculation time is greatly reduced. The proposed method is more suitable for the Vibration modal sensitivity analysis of large-scale engineering structures than the existing methods. © 2025 Chinese Vibration Engineering Society. All rights reserved.

关键词： 新工科   教学改革   材料力学   虚拟仿真   土木工程  

摘要： 以新工科背景为基础,围绕土木工程专业《材料力学》课程展开教学改革研究,提出并实践了"理论-实验-仿真"三位一体的复合型教学模式.通过深入研究和实践虚拟仿真,旨在培养学生理论基础、实验操作和解决实际问题的全面能力.该综合教学模式不仅加深了学生对材料力学复杂性的理解,更提升了他们适应未来工程领域挑战的能力,为新工科时代的教育贡献力量.

关键词： 模块   系统文献综述   英语发音   EFL学习者  

摘要： 在英语作为外语(EFL)语境下,翻转课堂环境中的语言习得方面,特别是针对提高我国非英语专业学生英语发音能力的研究较为匮乏.这些学生在发音方面遇到的困难通常归因于课堂教学中缺乏有效的策略.虽然关于英语发音教学的研究不断增加,但很少有评论专门研究翻转课堂教学模块的构成.旨在确定为 EFL学习者制定有效的翻转课堂英语发音教学模块的组成部分.进行了系统文献回顾,考察了 2018-2023 年间发表的 10 篇文章.出现了五个关键主题:模块的目的,干预持续时间、英语发音教学顺序、教学材料和对学生评估.这些主题被认为对于EFL背景下有效的英语发音教学至关重要,为教育工作者提供了宝贵的指导,并为学生提供了提高英语发音能力的机会.

关键词： 新课标   高中   英语阅读   高效课堂  

摘要： 新课标的出现为我国高中英语教学改革指明了全新方向.结合实际情况来看,新课标中对于学生学科核心素养的培养提出了更为具体的要求.对此,教师在落实英语阅读这一高中英语课程核心内容的课堂教学活动时,须从新课标角度出发,加大高效课堂的构建力度,并以此推动学生英语学科核心素养的形成与发展.

关键词： 艺术设计   技工教育   理论与实践   教学融合  

摘要： 艺术设计技工教育要培养高素质技能人才,必须加强理论与实践教学融合,这不仅有利于提升学生的综合职业能力,促进教学模式创新,还能实现产教深度结合.但当前两者融合还存在教学内容割裂、课程体系衔接不足、评价机制不完善等问题.分析了实践与理论教学融合的现状,从一体化课程体系构建、教学方法创新、评价考核机制完善等方面,探索了两者深度融合的策略,以期为艺术设计技工教育改革提供参考.

关键词： harmonic balance method   multi-directional vibration control   nonlinear energy sink (NES)   passive control  

摘要： Nonlinear energy sink (NES) has broad application prospects in passive control. However, studies in this filed mainly focus on unidirectional vibration absorbers to limit its applicability to multi-directional vibrations in practical applications. Here, a multi-directional NES was designed using 2 sets of mutually orthogonal steel wire structures to realize adaptive vibration absorption in any direction of a single vibrator space. Multi-directional vibration governing equations of the system were established based on Lagrange equation, and the harmonic balance method was used for approximate analytical analysis of the system' s steady-state response. The fourth-order Runge-Kutta method was used for numerical verification, and then the vibration reduction effect of the multi-directional NES was studied. The results showed that the multi-directional single vibrator NES can effectively suppress multi-directional vibrations and it is equally effective for any unidirectional excitation;this study can provide a reference for application and design of NES in multi-directional vibration control. © 2025 Chinese Vibration Engineering Society. All rights reserved.

关键词： Metal extrusion  

摘要： Metal material extrusion (MME) technology has great potential and advantages in industrial design, medical devices and other fields due to its low production cost, high material utilization rate, high design adaptability and environmental friendliness. However, due to layer-by-layer eumulative manufacturing method, mechanical properties of MME products are inferior to those of metal products processed by traditional subtractive methods. Here, to improve mechanical Performance of MME products, a Vibration assisted machining method was proposed utilizing the inverse piezoelectric effect of piezoelectric ceramics to introduce Vibration into green body forming process. Tensile and bending green body specimens with or without Vibration assistance were prepared, and then these specimens were treated with defatting and sintering to form densified pure metal specimens. Subsequently, static tests were conducted for green body specimens and sintered specimens, respectively, and the 2 specimen groups ' parameters of tensile strength, bending strength and strain were analyzed contrastively. The study results showed that Vibration assisted machining can significantly improve tensile and bending strengths of MME green body and sintered specimens, and effectively reduce orthogonal anisotropic features of their tensile and bending. © 2025 Chinese Vibration Engineering Society. All rights reserved.

关键词： aseismic Performance   geogrid   reinforced soil slope   shaking table test   slope face pattern  

摘要： Applications of geosynthetic-reinforced soil (GRS) slopes in infrastructure construction in high-altiturle strong earthquake areas of Tibet, China are gradually increasing. Different slope face patterns have different security effects when GRS slopes encounter earthquakes, but the previous studies on aseismic performance of GRS slopes with different slope face patterns are relatively lacking. Here, shaking table model tests for GRS slopes with geotextile bags and gabion cages were conducted to study effects of slope face patterns on dynamic response characteristics of geogrid GRS slopes under different seismic peak accelerations, especially, distribution laws of slope acceleration amplification coefficient, slope displacement, slope top settlement and geogrid axial force under earthquake action were examined. The experimental results showed that acceleration amplification factors at various locations of GRS slopes increase with increase in height, and slope face pattern has little effect on acceleration amplification factor;peak displacements of Overall upper slope surface gradually increase with increase in height, except for slope top, peak displacements of gabion cage group are smaller than those of geotextile bag group, and post-earthquake slope displacements are partially restored;slope top Settlements gradually increase with increase in seismic peak acceleration, and slope top Settlements of gabion cage group are larger than those of geotextile bag group;overall axial force of geotextile bag group reinforcement is larger than gabion group reinforcement' s, and axial force increment at reinforcement top is the largest under earthquake action;under peak earthquake acceleration of 1. 0g, both geogrid reinforced soil slopes using geotextile bags and gabion cages all have good aseismic Performance. © 2025 Chinese Vibration Engineering Society. All rights reserved.

关键词： acoustic black hole beam   critical coupling condition   piezoelectric shunt   Rayleigh-Ritz method   wave-based method  

摘要： Acoustic black hole structure is a feasible scheine to simultaneously meet Vibration control Performance requirements of lightweight, low power consumption and high reliability. Tip thickness truncation of actual acoustic black hole structure can produce significant wave reflection to cause obvious decrease in energy dissipation efficiency. Critical coupling condition of acoustic black hole structure has precise zero reflection coefficient to improve System energy dissipation efficiency. Here, an acoustic black hole beam structure was designed based on piezoelectric shunt, and the semi-analytical model of bending wave reflection coefficient was derived using the hybrid wave-based Rayleigh-Ritz method. By changing parameters of resistance-inductance shunt circuit, single and multiple critical coupling conditions of acoustic black hole beam structure were realized. Numerical results verified the effectiveness of the proposed semi-analytical model for reflection coefficient and the precise critical coupling condition tuning ability of piezoelectric shunt circuit. © 2025 Chinese Vibration Engineering Society. All rights reserved.