Is it obligatory to maintain kinship ties with an abusive grandfather?

If a grandfather unjustly assaults his grandchild, the grandchild is not blameworthy for harboring ill feelings towards him in their heart, as a person has no control over such emotions. However, a grandfather is a kin whom one is obligated to maintain ties with, and severing ties with him is forbidden. His wrongdoing does not permit the severing of ties, nor does it negate his right to be shown kindness, because maintaining kinship ties is not a matter of reciprocation. It is advisable to forget what happened, especially after the passage of years, due to the corruption and regret that recalling it entails, and the devil's ingress through sorrows.