per persson
- 20
- 1
- Homework Statement
- When are reactive forces enough to support the body such that no reactive moments need to be introduced for 2 or more supports
- Relevant Equations
- no equations
In the book engineering mechanics statics and dynamics Hibbeler says:" It should be noted that the single bearing supports in items (5) and (7), the single pin (8), and the single hinge (9) are shown to resist both force and couple-moment components. If, however, these supports are used in conjunction with other bearings, pins, or hinges to hold a rigid body in equilibrium and the supports are properly aligned when connected to the body, then the force reactions at these supports alone are adequate for supporting the body. In other words, the couple moments become redundant and are not shown on the free-body diagram. The reason for this should become clear after studying the examples which follow." And then he shows following examples
But I still don't understand when the reactive forces are enough to support the body such that no reactive moments need to be introduced. How can I determine from looking at the diagram that reactive moments are redundant?
But I still don't understand when the reactive forces are enough to support the body such that no reactive moments need to be introduced. How can I determine from looking at the diagram that reactive moments are redundant?
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