Hi,
There is nothing to be displayed on your screen since you didn't have added any visible object to the scene.
What you did is creating a texture (not a sprite), then you add a body and a shape to the space who are both invisible objects. Assigning the texture to the body data property will not add it to the scene. You have to do it manually.
Keeping the same code, just create a CCSprite with a method from your choice instead of a texture, assign it to the body's data property if needed (optional), and add it to the scene with addChild:(CCNode*)
Don't forget you'll have to update the sprite position/rotation values according to the body values to see it acting as in the physical space.
Does it sound clear to you ? There are some tutorials and example codes that should be a good starting point:
http://chipmunk-physics.net/documentation.php
or
http://www.alexandre-gomes.com/articles/chipmunk/