How would you handle a disrespectful relationship between your team members?

Talk to your team separately and jointly. Remind them with the fact that team spirit, which is based on respect, is very essential to achieve their common goals. 

Try to give them group assignments in order to make them cooperate with each other.

Sometimes you have to be tough when you see disrespectful behavior.

First, will sort things out on a professional manner, identify their issues and resolve it. If not resolved, company policies will apply. 

Will be resolved in two ways: By conciliation first and if not adjustable even then expulsion as a last resort.