30 higher than tension compression at each respective fatigue life cycles all together more than three test runs on coated plate specimens were conducted several interesting observations have been made from this investigation first much higher shaker driving force was needed for generating the same vibratory stress level for coated plates as for the uncoated ones this indicates that the vibratory stresses of the coated plates were significantly reduced or suppressed at the two stripe mode due to the addition damping contributed from the damping coating layers in turn during the test runs approximately 40 higher shaker driving force was imposed to generate desired fatigue limit stress such as 77 4 ksi at 10 6 cycles second surprisingly no single fatigue crack was able to be initiated at the maximum shaker capability u02dc 130 g on the first two test runs even though the maximum vibration stress on each test run had already reached to as high as 102 ksi which is about 31 higher than the fatigue limit stress 77 4 ksi of the uncoated plate no fatigue cracks were found during the test duration this indicates that the bending fatigue limit of the coated ti 6al 4v can be much higher than the uncoated one at high frequency stripe modes vibration however after improving the fixer design the third coated plate was fatigued at fatigue limit 121 ksi which is surprisingly about 55 higher than the fatigue limit 77 4 ksi of the uncoated ones in conclusion.