Tips on playing with Aatrox during team fights.

Hii

I love playing with Aatrox. I'm mostly able to dominate the lane early in the game and score some kills. However, I hardly score any kills once the team fights start. Ive observed that most of the times the players in the opposite team focus their attacks first on Aatrox. And Aatrox gets killed quickly. In such cases even his passive turns out to be useless. I am not an expert player and I might be doing something wrong. Can you give me some tips/suggestions/advice on how to play with Aatrox during team fights?

This is my final build - Blood Thirster, Spirit Visage, Maw of Malmortius, Randuin's Omen, Zephyr, Frozen Mallet.

Thanks!