If you are the respondent and you fail to appear at a domestic violence injunction hearing after being properly served, the judge can enter a permanent injunction against you. This could significantly affect your rights and subject you to arrest if you later violate the injunction. If you are the petitioner and fail to appear at the hearing, the judge could dismiss your case and dissolve any temporary injunction that's already been entered. This could jeopardize the protections that are part of the temporary injunction.
Either way, failure to appear at a domestic violence hearing is rarely adviseable. You need to speak to an attorney in your area as soon as possible who has experience in domestic violence issues. That attorney will be able to better address the specific circumstances in your case.
As the petitioner, you would likely have your petition dismissed. If there are any temporary injunctions in place, those could be dismissed as well. Anytime you have a hearing schedule with the court, it is in your own best interests to attend. If you no longer request an injunction be entered, you should attend the hearing and inform the court of your wishes. If a pattern of filing petitions for injunctions and not attending the hearings develops, you may lose credibility in the eyes of the court. As with most issues, speaking with an attorney in your area would be advised.
Are you the petitioner or the respondent? You need to appear if you want to go forward with the injunction as the petitioner. If you do not appear, most likely, the petition will be dismissed.
If you are the respondent and don't appear while the petitioner does appear, the court can order an injunction against you.