"受引力作用" can be translated into English as "be subject to gravitational force" or "be influenced by gravity".
For example:
The planets in the solar system are subject to gravitational force from the sun. （太阳系中的行星受太阳引力的作用。）
Objects fall to the ground because they are influenced by gravity. （物体落地是因为它们受到引力的作用。）