An applied laser shade vibration measurement technique for rotating imbalance for quality testing of solid tires

A non-contact vibration measurement technique with linearity, simplicity, reliability and low cost to investigate rotating imbalance for quality testing of solid tires is proposed with an explanation of experimental results. The non-destructive testing technique consists of a 5 mW, 670 nm laser diode and a 100 kHz bandwidth photodiode. Initially, the surface of a rotating shaft is set to block a half part of the light beam emitting into the photodiode. When the axle of the rotating shaft oscillates due to a rotating imbalance, the light beam emitting into the photodiode varies and the displacement of the surface due to vibrations relative to a setup position is detected as voltage signal by the photodiode. This vibration measurement technique can be used to detect vibratory motion of a rotating shaft equipped with a solid tire. For each of the 18 solid tires in the experiment, 15 replication tests were performed in order to ascertain reliability of the technique under identical conditions. Test results also revealed that vibration displacements due to rotating imbalance of locally manufactured solid tires were greater than those of imported ones.