Results 21 to 30 of about 6,681 (167)
Behavior of a Flexspline in Harmonic Drive [PDF]
谐波齿轮传动是利用柔性工作构件的弹性变形波进行运动或者动力传递的一种新型传动方式,因其具有体积小、重量轻、精度高、单级传动比大、承载能力高等诸多优点,在航空航天、机器人、数控机床等领域得到了广泛的应用。柔轮作为谐波齿轮传动的关键构件很大程度上影响了谐波齿轮传动的承载能力、使用寿命等。柔轮为弹性薄壁件,在交变载荷作用下易导致齿面磨损和疲劳断裂。柔轮强度、变形与应力分析对谐波齿轮传动过程中的疲劳断裂评估及传动性能研究具有重要的意义。 本文首先根据已知参数、实际工况和谐波齿轮传动啮合参数选取原则 ...
刘淳剑
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Sri Lanka's biodiversity is threatened by habitat loss, climate change, and ineffective traditional conservation methods. Integrating plant tissue culture and DNA barcoding offers scalable, precise tools for conserving rare and endemic species. This review emphasizes the potential of biotechnological approaches to enhance conservation accuracy and ...
Mylange Dona Kasundi Mekhala Gunasena +2 more
wiley +1 more source
Hyperspectral outcrop models for palaeoseismic studies
To overcome the limitations of the traditional study of palaeoseismic trenches, a new workflow is presented that integrates infrared hyperspectral and photogrammetric data. This method was applied on two palaeoseismic trenches excavated across a post‐glacial fault scarp in northern Finnish Lapland.
Moritz Kirsch +19 more
wiley +1 more source
Design and Simulation of Contact Fatigue Testing System of Flexspline and Circular Spline in Harmonic Drive [PDF]
谐波齿轮传动是随着空间技术的发展而诞生的一种新型传动方式,其工作原理是利用柔轮的弹性变形波来实现运动或者动力传递,因其具有结构简单、传动精度高、传动比大等诸多优点,在航空、航天、机器人等领域得到了广泛应用。在谐波齿轮传动过程中,柔轮的运动情况比较复杂,作为弹性薄壁构件需承载交变应力,容易造成齿面磨损和疲劳断裂。因此,建立合适的模型对谐波齿轮传动过程中柔轮的错齿运动进行模拟分析具有重要意义。 本文首先针对谐波齿轮传动过程中柔轮的错齿运动设计了一种新的接触疲劳试验装置 ...
吴泽林
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Read the free Plain Language Summary for this article on the Journal blog. Abstract Many studies have focussed on niche differentiation at the population level to explain the coexistence of similar species. However, information on how individual‐level processes across multidimensional niches shape community dynamics and species coexistence, especially ...
Man Si +8 more
wiley +1 more source
由于拉索内部的力学性能比较复杂,采用有限元方法进行拉索分析。对于钢绞线的有限元模型,目前多采用Solid164单元来进行建模,而对于半平行钢丝束拉索的有限元模型,目前多采用Pipe16单元来进行建模。该模型的特点是由短梁单元和弹簧单元组成。分别采用Pipe16单元和Solid164单元来建立拉索模型,分析了两种有限元模型的弯曲荷载-挠度曲线和拉索的有效弯曲刚度,并与试验数据进行了对比分析。结果表明,对于无预应力条件下,Pipe16单元的模型结果与试验数值误差比Solid164模型的要大 ...
马红旭 +3 more
doaj
Bridge Damage Detection under Structural Health Monitoring System Based on Influence Lines [PDF]
在过去几十年内,中国修建了许多大跨径桥梁,这些桥梁一经建成就开始了结构劣化的过程,且损伤在整个服役期间不断累积,该类损伤甚至可能造成桥梁坍塌事故。因此,不少新建的大跨桥梁上都安装了结构健康监测系统,用以监测桥梁健康状态。但截止至目前,将健康监测系统的实测数据运用于桥梁损伤识别,至少有以下三点关键问题尚未有效解决:(1)从监测系统的实测数据中提取出对损伤敏感而对环境变化不敏感的损伤指标;(2)利用监测系统多传感器信息增强损伤决策的可信度;(3)优化传感器布置方案以达到最好的损伤识别效果 ...
蔡亲霖
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ABSTRACT Objectives The primary aim was to validate the International Ovarian Tumor Analysis (IOTA) benign simple descriptors (BDs) followed by the Assessment of Different NEoplasias in the adneXa (ADNEX) model, if BDs cannot be applied, in a two‐step strategy to classify adnexal masses identified during pregnancy. The secondary aim was to describe the
J. Barcroft +8 more
wiley +1 more source
Research on Structural Design and Mechanical Behavior of Double Arc Tooth Profile Harmonic Drive [PDF]
谐波齿轮减速器是一种传动精度高、减速比大并能够在密闭空间传动的齿轮传动机构,应用领域广泛,尤其在航空航天领域有不可替代的优势。常用的渐开线齿廓齿根处会出现应力集中以及齿顶产生尖点啮合现象,影响其承载性能和啮合质量。双圆弧齿形谐波齿轮以其良好的承载能力与啮合性能逐渐成为研究热点,本文根据谐波齿轮设计理论设计了双圆弧谐波齿轮装置,并对其结构性能、接触特性以及动力学等方面的分析,探索相关规律,为后续在结构优化、增强啮合性能提供了一定的理论依据。 论文主要包括以下几方面内容: 1 ...
王萌萌
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Research Progress and Forensic Application of Human Vascular Finite Element Modeling and Biomechanics [PDF]
The finite element method (FEM) is a mathematical method for obtaining approximate solutions to a wide variety of engineering problems. With the development of computer technology, it is gradually applied to the study of biomechanics of human body.
Yong ZENG, Dong-hua ZOU, Ying FAN, Qing XU, Lu-yang TAO, Yi-jiu CHEN, Zheng-dong LI
core +1 more source

