Does divorce take place if a husband stipulates that his wife must not spend the night outside the home, and she does so, knowing that he did not explicitly inform her of divorce after the act occurred?

Spouses should fulfill their duties and avoid anything that disturbs their marital harmony, resolving disputes through dialogue.

Regarding the vow you made, if it was a mere intention in the heart and you did not utter it, then nothing is binding upon you. However, if you uttered it and intended to make the divorce contingent upon your wife spending the night at her aunt's house without an excuse, then divorce has occurred the moment she did so. You may take her back before her waiting period ('iddah) ends, provided this divorce does not complete the three divorces. The wife's knowledge or consent is not required for the return.

But if you did not intend to make the divorce contingent but rather promised it for the future, then you are not obligated to fulfill this promise.