A B737-300 ACFT; DURING CLIMBOUT; EXPERIENCED SIGNIFICANT AIRFRAME BOUNCING/VIBRATION WHILE ACCELERATING THROUGH 230 KNOTS. SAME CONDITION DURING DESCENT.

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ON CLBOUT FROM ZZZ WE NOTICED SIGNIFICANT AIRFRAME BOUNCING/VIBRATION WHILE ACCELERATING THROUGH 230 KTS. I WAS HAND FLYING AT THE TIME AND NOTHING ABNORMAL COULD BE FELT THROUGH THE CTL SURFACES. ADDITIONALLY; THE FLT ATTENDANTS DID NOT NOTICE THE CONDITION. AS WE ACCELERATED THROUGH 250 KTS AND GAINED ALT; THE BOUNCE/VIBRATION BECAME LESS PRONOUNCED. HOWEVER; THE CONDITION EXISTED THROUGHOUT THE FLT. THE FO AND I DISCUSSED THE FLT MANUAL SECTION ON VERT BOUNCE AND I DISCUSSED THE SITUATION WITH DISPATCH AND MAINT CTL. WE MADE THE DECISION TO CONTINUE TO ZZZ1 AS THE CONDITION APPEARED STABLE AND DISSIPATING. THE BOUNCE/VIBRATION WAS SLIGHT AT FL370 AND REDUCED AS WE PROGRESSED. DURING DSCNT THE CONDITION BECAME MORE PRONOUNCED AS WE PASSED THROUGH FL300; BUT NEVER REACHED THE SEVERITY OF THE CLBOUT VIBRATION. THE APCH AND LNDG WERE UNEVENTFUL. MECHS MET THE FLT AND WE BRIEFED THEM AND THE OUTBOUND FLT CREW. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THIS PARTICULAR ACFT VERTICAL BOUNCE VIBRATION WAS NOT A HIGH FREQUENCY TYPE OF LIGHT CHOP THAT PILOTS EXPERIENCE FROM ATMOSPHERIC CONDITIONS. IN HIS CARRIER'S FLIGHT MANUAL THERE IS A PAGE THAT DESCRIBES VERTICAL BOUNCE AND CAUSES; BUT THOSE EXAMPLES DID NOT FIT THEIR EXPERIENCES ON THIS ACFT. REPORTER ALSO STATES THE SAME ACFT WAS PULLED OUT OF SERVICE; INSPECTED; BUT NOTHING PHYSICALLY FOUND ON THE EXTERNAL SURFACES THAT MAY HAVE CONTRIBUTED TO THE VIBRATION.