Oh goodness, yes I have. I think my second-worst injury on beam was when I split the beam on a switch leap, wound up slamming my nose into it. I have a scar on my thigh from that sucker. I've split the beam probably 2 or 3 other times.
I've split the beam on a leap probably 3 or 4 times; always very painful. The first time I did it, I caught myself and ended up hanging from the bottom with my arms and legs wrapped around the beam.