WHILE IN THE TRAFFIC PATTERN, NORMAL AND EMERGENCY ATTEMPTS TO LOWER THE LANDING GEAR WERE UNSUCCESSFUL. THE PILOT-IN-COMMAND THEN LANDED INTENTIONALLY GEAR UP IN GRASS ADJACENT TO THE RUNWAY AND THE AIRCRAFT SLID TO A STOP, CAUSING MINIMAL DAMAGE. FURTHER ANALYSIS OF WRECKAGE PHOTOGRAPHS BY PIPER AIRCRAFT PROVED SUBSTANTIAL DAMAGE WAS CAUSED BY AERODYNAMIC OVERLOADING IN THE AIR PRIOR TO THE LANDING.