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Mechanical Engineering

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Torsion

Shear Flow in Thin-Walled Shafts

Description

Shear flow in a thin-walled hollow shaft describes how torsional force is carried through the wall. When a small segment of width dx is isolated, it is still in equilibrium, but it experiences torsional shearing forces at its ends. These forces come from the longitudinal shearing stress on the segment's minor surface multipl...

Transcript

考虑一段受扭转载荷作用的薄壁空心轴,其壁厚为 't',从中取一宽度为 'dx' 的微小部分。

由于该部分处于平衡状态,作用在其上的唯一力是施加在该部分两端的剪切力。

将剪切力表示为小面上纵向剪应力与该面面积的乘积,可推导出剪流的表达式,该表达式在构件内保持恒定。

现在,考虑空心轴壁截面上一段长度为“ds”的微小单元。作用在该单元上的剪切力大小可表示为剪切流与单元长度的乘积。

该力对空心轴孔内任意点 O 的力矩,可通过将力乘以点 O 到力作用线的垂直距离得到。

对力矩方程进行积分,可得到作用在整个薄壁空心圆柱体上的扭矩表达式。