How to calculate the support for the withdrawal of two fulcrums
Conclusion: when the fulcrum is between two forces, the two forces are vertical and the lever is balanced, the force on the fulcrum is always equal to the sum of the two forces
the following is an example:
clipping is shown in the figure. The diameter of pin C and copper wire is d = 5mm. When the applied force P = 200N, calculate the average shear stress of the cross section between the copper wire and the pin τ It is known that a = 30mm, B = 150mm
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according to the balance of moment and force, the reaction force of support is calculated
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the rectangular coordinate system is established with the left end point of section a as the origin, the beam as the X axis and the deflection as the Y axis
The maximum bending moment can be obtained by writing the bending moment function at any position of the beam The deflection can be obtained by integrating the bending moment function twice< br />
If a piece of wood is placed at the end of the lever, the supporting force of the two fulcrums to the lever will change
be able to judge whether the lever is balanced by the supporting force of the fulcrum.
1. If the object under force is a rigid body and the direction of the force is vertical and downward, then the two fulcrums bear the same force
2. If there is deflection in the structure, that is, the stressed object will deform after being stressed, and the direction of the force is vertical and downward, then the point near which the stress point is located will bear more force< In addition, if the fulcrum is not on the same horizontal plane. The fulcrum can be projected onto a plane perpendicular to the direction of the force, and then judged according to the above rule.
has been solved, hope to be helpful
Stress analysis:
the closing moment of point a is 0: F2 × B = 0, F2 = 0
y direction resultant force is 0: f1-f = 0, F1 = F