No, if A+ blood is donated to B+ blood, the blood should not coagulate or clump. Blood type compatibility is determined by the presence or absence of certain antigens on the surface of red blood cells, and A and B are two different types of antigens. A person with blood type A has the A antigen on their red blood cells, while a person with blood type B has the B antigen. A person with blood type AB has both A and B antigens, while a person with blood type O has neither.
In general, blood type compatibility for transfusions follows the rule that a person can receive blood from someone with the same antigen (or no antigen) as themselves. So, a person with B+ blood can receive blood from someone with B+ blood, AB+ blood, O+ blood, or B- blood. They cannot receive blood from someone with A+ blood, as the A antigen would trigger an immune response and cause the blood to clump.
~~~Harsha~~~