Results 31 to 40 of about 6,142 (167)
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
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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Abstract Prior research in health equity, including food security, indicates that disadvantaged groups, such as women with limited resources, face many obstacles in achieving food security. One of the first of its kind to draw on intersectionality and the social determinants of health frameworks, this study identified and tested gender differences in ...
Farzaneh Barak +2 more
wiley +1 more source
Nonlinear finite element analysis for seismic performance of high-strength concrete beam-column joints with new reinforcement details [PDF]
Because the factors that affect the behavior of the beam-column joints are complicated, an experimental study alone is not sufficient. Therefore, a nonlinear finite element analysis was conducted to provide better understanding of the performance of the ...
Gan, L, Li, J, Pam, HJ
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Abstract The availability of hospital‐based dental services across Australia varies with a number of hospitals disestablishing dental departments due to rising costs. However, the perceived costs are difficult to quantify as funding models used to capture activity are not uniform across health facilities.
Pritam Daniel Sundaresan +3 more
wiley +1 more source
为了更深入了解金属蒙皮支撑连续檩条在整体蒙皮结构中所起的作用,为今后我国对连续檩条以及蒙皮结构的设计、计算提供依据,通过足尺模型试验和有限元模型的分析,研究了蒙皮支撑冷弯薄壁连续型钢檩条模拟风吸力作用的承载力。利用有限元程序ANSYS建立了带有非线性弹簧单元模拟自攻螺钉这一符合实际连接状况的有限元模型,与足尺试验模型的失稳模式、荷载-位移曲线、连接强度以及连接刚度的规律等相对比,验证了有限元模型的合理性、有效性及适用性。
潘宇 +6 more
doaj
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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Exploring of the Mechanism of Rib Fracture Caused by Landing on Different Parts of the Trunk after Falls from Height Using Finite Element Method [PDF]
Objective To study the mechanism of rib fracture caused by landing on different parts of the trunk using finite element method, and to provide some new techniques and new ideas for the reconstruction of the whole process of falls from height. Methods The
HU Wen-hu, SHAO Yu, LI Zheng-dong, et al
core +1 more source
Wildlife mortality risk posed by high and low traffic roads
Abstract Wildlife mortality due to collisions with vehicles (roadkill) is one of the predominant negative effects exerted by roads on many wildlife species. Reducing roadkill is therefore a major component of wildlife conservation. Roadkill is affected by various factors, including road attributes and traffic volume.
Dror Denneboom +2 more
wiley +1 more source
Imaging anatomy and hemodynamic simulation of the extracranial segment of vertebral artery [PDF]
研究背景:椎-基底动脉系统是脑组织供血的重要血管之一,主要为脑干、小脑及双侧大脑半球后1/3供血。双侧椎动脉(vertebralartery,VA)主要发自于锁骨下动脉,于C6水平入横突孔,穿行于上6颈椎横突孔内,经枕大孔入颅;在脑桥前下合并为基底动脉,其寰枢段走行弯曲,周围解剖结构复杂。深入研究椎动脉的相关形态及血流动力学,对提高后循环缺血诊断和治疗具有重要的临床意义。 目的:(1)利用多排螺旋CT(multi-slicespiralCTangiography,MSCTA ...
许兵强
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