AER 403 Lecture Notes - Lecture 21: Vibration Isolation, Accelerometer, Hertz

• School: Ryerson University
• Department: Aerospace
• Course: AER 403
• Professor: Fengfeng Xi

Document Summary

An engine of 100 kg is mounted on a spring of k=700 kn/m. The unbalance induced vibration is (cid:885)(cid:887)(cid:882) n at (cid:885)(cid:882)(cid:882)(cid:882) rpm, and =(cid:882). (cid:884). Required to determine: force induced vibration amplitude, 2) transmissibility, 3) transmitted force. Example 10. 2 vibration isolation (cid:883)(cid:524) n=(cid:523)k/m(cid:524)(cid:883)/(cid:884)= (cid:523)(cid:889)(cid:882)(cid:882) (cid:883)(cid:882)(cid:882)(cid:882)/(cid:883)(cid:882)(cid:882)(cid:524)(cid:883)/(cid:884)=(cid:890)(cid:885). (cid:888)(cid:889) (cid:523)rad/s(cid:524) = (cid:523)(cid:885)(cid:882)(cid:882)(cid:882)/(cid:888)(cid:882)(cid:524) (cid:884) = (cid:883)(cid:882)(cid:882) (cid:523)rad/s(cid:524) x=(cid:523)fo/k(cid:524)/[(cid:523)(cid:883)- (cid:523) / n(cid:524)(cid:884)(cid:524)(cid:884)+(cid:523)(cid:884) (cid:523) / n(cid:524)(cid:524)(cid:884)](cid:883)/(cid:884) 2] =0. 137: ft=fo tr=350 0. 137 = 47. 89 n. Course outline: support motion, vibration isolation vibration sensors. Accelerometers: accelerometers are designed utilizing support motion in the range of. Accelerometers: accelerometers are made of piezoelectric crystals that have high natural frequency in the range of over 50 khz, the size of the accelerometer is small, about 1 cm, and very light between 0. 5-50 grams. The sensitivity of the accelerometer is given in mv/g: accelerometers measure the acceleration in range of 100 (cid:883)(cid:882)k (cid:523)g(cid:524). Example: if mv/g=5, vibration is y=2sin1(cid:882)(cid:882)(cid:882) t (cid:523)mm(cid:524), what will be the.