SHEILD EXPLAINED!
the absorption characteristics of Vibranium; Vibranium has the ability to absorb energy from impacts and quickly disperse it. When attempting to describe and explain this using science, one should consider a significant law of energy: energy cannot be created nor destroyed; it can only be converted and take other forms. This means that in order for the shield to suppress such blows, it should convert the kinetic energy from the impact and quickly convert it to sound or light. Since neither is seen as a byproduct of a blow on Captain America's shield, the only explanation is that the kinetic energy gets absorbed in the atomic bonds of the material – Vibranium
WELCOME THE SHEILD!
Putting aside his powers, another iconic aspect of Captain America which gives him an edge over his enemies is his indestructible shield. According to the comics and movies, the shield is made of a mythical and alien metal that goes by the name of Vibranium – able to take on the mightiest blows without hurting its carrier!
"Whatever happens tomorrow you must promise me one thing. That you will stay who you are. Not a perfect soldier, but a good man."