I Virtual work and constraint forces

AI Thread Summary
In a system of N particles with constraints, performing a virtual displacement on one particle can cause other particles to move in response. The inquiry focuses on calculating the virtual work done by constraint forces on all particles involved, questioning whether a non-zero result is possible for the work done on the single particle. The discussion references a book that states the total virtual work done by all particles must equal zero, in accordance with the principle of virtual work. However, it clarifies that the work done on an individual particle does not necessarily have to be zero. The principle emphasizes that while the net virtual work is zero, individual contributions may vary.
Ahmed1029
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Suppose I'm considering a system of N particles that are constrained in their possible motions and so there are less that 3N generalized coordinates. Suppose now I perform a virtual displacement on one particle, which due to some constraints might force some other particles to more virtually with it, like the case of an atwood machine. I now want to calculate the virtual work done by the constraint forces on the particles that move as a corrolary to the movement of this single particle plus the work done on this particle itself, can I get a non-zero result? I'm asking because the book I'm reading assers that the virtual work done by virtually moving ALL the particles has to be zero, and not necessarily the work done to move a single particle has to be zero.
 
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