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HIGH SCHOOL

Engineering

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Mechanical Engineering

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Internal Forces

Beam Shear Force Diagram

Description

Beam shear force diagrams show how shear changes along the length of a supported beam. In beam mechanics, they help students track the internal shear force caused by perpendicular loads. The beam AB in this example is supported at both ends, so the first step is to draw a free-body diagram that shows the external forces and ...

Transcript

剪力图是沿梁长度方向剪力分布的图形表示。

考虑一根两端支撑的梁AB,且受到垂直载荷作用。绘制其剪力图。

绘制梁的受力图。利用力和力矩的平衡方程,可计算出每个支座处的支座反力。

将该方法应用于梁。

接下来,考虑在 AP 区域内距 A 点任意距离处的截面。绘制该截面的受力分析图。在平衡条件下,该截面上的剪力等于支座处的反作用力。

类似地,考虑 PQ 区域内的任意一点。通过绘制受力图并利用平衡方程,可确定该截面上的剪力。

最后,考虑 QB 段内的任意一点。通过绘制受力体图并回顾平衡方程,可确定该截面上的剪力,该剪力保持恒定直至梁的末端,最终降为零以维持平衡。