相关实验视频
Updated: May 27, 2025

11:41
Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
23.2K
重复关闭扭矩对扭矩损失和角度偏差的影响:一个体外研究
Ruoyan Guo1, Yantao Qian2, Guohai Lin2
1Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Laboratory of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, PR China.
The Journal of oral implantology
|February 20, 2025
概括
牙植入物螺丝的重复拉紧和松动会增加扭矩损失,特别是在较窄的植入物中. 建议限制螺丝重新紧固周期,以防止松动和断裂等并发症.
科学领域:
- 生物材料科学 生物材料科学
- 牙科植入物学 牙科植入物学
- 机械工程 机械工程
背景情况:
- 中枢螺丝松动和断裂是植入物修复中经常出现的机械并发症.
- 在制造和维护过程中重复操纵螺丝对这些并发症的影响尚不清楚.
研究的目的:
- 在不同直径的牙科植入物中,在重复拉紧和松动中央螺丝后调查扭矩损失.
- 为了评估中央螺丝与植入物相对的角度偏差的变化.
主要方法:
- 20个牙科植入物 (直径3.7mm和4.5mm) 经历了10个循环的拉紧和松,在15N.cm或35N.cm的闭合扭矩下.
- 记录了反向扭矩测量和角度偏差.
- 使用扫描电子显微镜分析了表面磨损.
主要成果:
- 在所有组中,每次收紧循环时,扭矩损失显著增加.
- 较小的植入口径 (3.7mm) 与较大的直径 (4.5mm) 相比,显示出较大的扭矩损失.
- 角度偏差受到关闭扭矩和周期数的影响,但不是植入物直径.
结论:
- 重复的螺丝操纵会导致扭矩损失和角度偏差的增加,特别是在直径窄的植入物中.
- 植入物直径是影响扭矩损失的关键因素.
- 建议在狭窄的植入物中限制重新紧缩周期,以减轻机械并发症.
相关概念视频
Residual Stresses in Circular Shafts
153
In materials that exhibit elastic and plastic behavior, known as elastoplastic materials, residual stresses can accumulate when these materials experience plastic deformation. This deformation arises from either high levels of shearing stress or significant strains. Residual stresses are internal stresses that persist within a material after removing the external force causing deformation. This phenomenon is demonstrated when observing the behavior of a shaft under torque; notably, the...
153
Circular Shafts - Elastoplastic Materials
91
The study of solid circular shafts under stress shows that within the elastic limit, stress increases directly to the distance from the shaft's center. This relationship holds until the shaft reaches a critical point of stress, beyond which it begins to yield, marking the transition from elastic to plastic deformation. At this crucial juncture, the maximum torque the shaft can endure without permanent deformation is determined, signifying the limit of its elastic behavior.
As torque on the...
As torque on the...
91
Screw: Problem Solving
386
In mechanical engineering, the interaction between a threaded screw shaft and a plate gear involves analyzing the resisting torque on the plate gear that can be overpowered when a specific torsional moment is applied to the shaft. To better comprehend this concept, consider a generic situation with a threaded screw shaft with a given mean radius and lead and a plate gear with a specified mean radius. The coefficient of static friction between the screw and gear is also provided.
To evaluate the...
To evaluate the...
386
Net Torque Calculations
9.0K
When a mechanic tries to remove a hex nut with a wrench, it is easier if the force is applied at the farthest end of the wrench handle. The lever arm is the distance from the pivot point (the hex nut in this case) to the person’s hand. If this distance is large, the torque is higher. Only the component of the force perpendicular to the lever arm contributes to the torque. Therefore, pushing the wrench perpendicular to the lever arm is more advantageous. If multiple people apply force to...
9.0K
Stress Concentrations in Circular Shafts
160
Consider the elastic torsion formula, which applies to a circular shaft with a consistent cross-section. This formula assumes that the shaft's ends are loaded with rigid plates firmly attached. However, in many cases, torques are applied to the shaft through mechanisms like flange couplings or gears, which are connected by keys inserted into keyways. This application method modifies the stress distribution near the point of torque application, causing it to deviate from the distributions...
160
Thin-Walled Hollow Shafts
161
In analyzing a thin-walled hollow shaft subjected to torsional loading, a segment with width dx is isolated for examination. Despite its equilibrium state, this segment faces torsional shearing forces at its ends. These forces are quantitatively described by the product of the longitudinal shearing stress on the segment's minor surface and the area of this surface, leading to the concept of shear flow. This shear flow is consistent throughout the structure, indicating a uniform distribution...
161

