As long as they have been correctly and properly fitted, not likely. But heavy shunts can still cause damage.
RAM will very rarely become dislodged if it has been fitted correctly.
The GPU is at more risk depending on its size, it could sooner bend and sag, which could both damage the GPU and Motherboard.
So it can depend on how hard you are hitting it, little knocks will likely not do anything if everything is properly secured, either way, constantly knocking it is only going to cause problems if anything.