相关实验视频
Updated: Sep 17, 2025

07:36
C. elegans Tracking and Behavioral Measurement
Published on: November 17, 2012
19.2K
在螺旋绕的虫中,魔法角度和力传输
Olaf Ellers1, Matthew J McHenry2, Amy S Johnson1
1Biology Department, Bowdoin College, Brunswick, 04011, ME, USA.
Integrative and comparative biology
|June 27, 2025
概括
螺旋绕的生物结构,如触角和体,利用纤维角度获得机械优势. 结合力传输的新理论揭示了这些结构如何管理压力和形状变化,以实现高效的运动.
科学领域:
- 生物力学 生物力学
- 软物质物理学 软物质物理学
- 比较解剖学的比较解剖学
背景情况:
- 许多动物结构 (例如,鱼的触角,线虫体) 是压力级的圆柱体,具有螺旋式纤维包裹.
- 经典研究侧重于几何学,但缺乏对软骨的明确力分析.
- 最近的理论结合了力传输,以更深入地了解生物水静态.
研究的目的:
- 开发一个更精确的理论,用于螺旋绕生物结构的机制.
- 为了研究纤维角度和力传递在水静态骨的功能中的作用.
- 阐明这些系统中几何,压力和机械优势之间的关系.
主要方法:
- 用螺旋式纤维包装压缩圆柱形结构的分析.
- 机械原理的应用,以了解力传递和形状变化.
- 几何效应与基于力的机械模型的比较.
主要成果:
- 在魔法角度 (54.7°) 的交叉螺旋纤维可以承受压力气中的所有应力.
- 恒定体积的圆柱体,其不可伸缩的纤维在除了魔力角度以外的角度上储存能量并改变形状.
- 气的几何形状 (面积比) 显著影响力传输的机械优势.
结论:
- 对力传递的明确考虑为水静态骨架力学提供了关键的见解.
- 纤维角度,圆柱体几何形状和肌肉排列决定了机械和排位优势.
- 了解这些原则可以解释各种各样的生物功能,从挖掘到尾运动.
相关概念视频
Angle of Twist: Problem Solving
402
An electric motor applies a torque of 700 N·m to an aluminum shaft, triggering a stable rotation. Two pulleys, B and C, are subjected to torques of 300 N·m and 400 N·m, respectively. The modulus of rigidity is provided as 25 GPa. With the knowledge of the length and diameter of each segment, the twist angle between the two pulleys can be computed. First, a section cut is made between pulleys B and C, and the cut cross-section is analyzed using a free-body diagram. Given that the...
402
Angle of Twist - Elastic Range
419
Consider a cylindrical shaft with a length denoted by L and a consistent cross-sectional radius referred to as r. This shaft undergoes a torque at the free end. The highest shearing strain within the shaft is directly proportional to the twist angle and the radial distance from the shaft axis. When the shaft behaves elastically, this shearing strain can be articulated using variables such as the applied torque, radial distance, the polar moment of inertia, and the modulus of rigidity. By...
419
Transmission Shafts: Problem Solving
295
Designing a solid shaft that transmits power from a motor to a machine tool involves a series of calculations to ensure the shaft can withstand the stresses applied by bending moments and torques. First, calculate the torque exerted on the gear, considering the power transmitted by the shaft and its rotational speed. Following this, compute the tangential forces acting on the gears, which directly relate to the torque and the gear radius.
Next, use bending moment diagrams for the shaft to...
Next, use bending moment diagrams for the shaft to...
295
Deformation in a Circular Shaft
453
One of the distinctive characteristics of circular shafts is their ability to maintain their cross-sectional integrity under torsion. In other words, each cross-section continues to exist as a flat, unaltered entity, simply rotating like a solid, rigid slab. To understand the distribution of shearing stress within such a shaft, consider a cylindrical section inside this circular shaft. This section has a length of L and a radius of R, with one end fixed. The radius of the cylindrical section is...
453
Unsymmetric Bending - Angle of Neutral Axis
450
Unsymmetrical bending occurs when a structural member is subjected to bending moments in a plane that does not align with the member's principal axes. This scenario typically arises in beams and other structural components when loads are applied at non-ideal angles, introducing complexities in stress analysis.
When a bending moment is applied at an angle θ concerning the vertical axis of a symmetrical member, it can be resolved into components along the member's principal...
When a bending moment is applied at an angle θ concerning the vertical axis of a symmetrical member, it can be resolved into components along the member's principal...
450
Thin-Walled Hollow Shafts
255
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...
255

