Andrew Yang posted a new Pixel Bender filter late last month at AE Scripts, YY_ShockRing. It's a 2D ring generator, not so different from the Circle effect built into After Effects. ShockRing is intended to create a "texture for shockwaves, etc for visual effects. It has enough options to be fairly flexible, but not so much as to be overbearing." Pixel Bender plug-ins work in AE and Photoshop CS4 and CS5.
Shockwaves are high energy waves most often seen in explosions; see BANG! The Anatomy of Explosions at AE Portal for some resources on explosions. In AE "shockwave" usually refer to those seen in space operas.
Here are a few resources for those:
- Andrew Kramer has tutorials on 2 types of shockwaves at Video Copilot, Blast Wave and Planet Explosion.
- Creating Shockwaves: Part Three of the Golden COW by Serge Hamad is part of a series that requires several 3rd-party filters to create tongue-in-cheek effects, nebulas, etc.
- Scott Frizzle posted a free AE project in 2006 (pre-CS3), Novaticular, which animates a supernova over starfield background. It uses Trapcode Particular; Knoll Lens Flare Pro was used for the light flare, but other light effects (like Optical Flares) can substitute.
- An AE preset posted to YouTube seems viable and adjustable -- see After Effects Preset: Shockwave by Mocarg.
- AE Help says that you can animate the Radius property of the Shatter effect from small to large to generate an expanding shockwave explosion.
- Some forums posts (example 1, 2) explain how to construct a shockwave.
- Not especially on-topic but quite fun is Maltaannon's video tutorial on the Circle effect, Uses of the Circle.