At about 1430 Central time, the airplane sustained substantial damage following a hard landing. The Private pilot and passenger were not injured. Visual conditions prevailed for the cross-country flight, which originated near McKinney, Texas. The pilot later reported being a little high and fast on final and was making throttle and pitch corrections. She was pulling back slightly on the yoke when the rear wheels touched down, but the airplane porpoised and came off the ground. The pilot then elected to abort the landing, added full power, continued around the traffic pattern, landed successfully and taxied the airplane to parking. A subsequent inspection revealed structural damage to the firewall.