- Q3 A Fire Sprinkler Pump Is Installed On The Basenent Floor Of A Building Which Ean Be Modeled As A Rigid Rectangular P 1 (35.46 KiB) Viewed 36 times
Vibration Subject
Q3 A fire sprinkler pump is installed on the basenent floor of a building, which ean be modeled as a rigid rectangular plate resting on four elastic columns as shown in Figure Q3. The equivalent mass of the sprinkler purmp is m1 of 150×Pkg and it is observed to vabrate badly at a frequency of 10 Hz. The vibration is caused by the application of a harmonic force, F of 100×Q N to the pump. A hypolsesis was made by a mechanical engineer that the excessive vibration is due to the frequency of the harmonic force which coincides with the natural frequency of the sprinkler purmp. (a) Based on the hypothesis made by the engincer, suggest the possible solution to overeome the vibration problem. Please grve a reason to stupport your answer. (4 marks) (b) If the sprinkler pump can be modeled as a single degree of freedom spring-mass system, calculate the stifiness, k for each elastic column possessed. Give the final answer in the unit of kN/m. (6 marks) (c) Analyze the mass and stiffiness of the attachod device that would eliminate vibrations of the sprunkler jump at a frequency of 10It, if given the amplinade motion of the device naws, Xe at 10H, is observed to be 0.0t×R in. (6 marks) (d) Determine the ncw natural frequencies of the system after the device is attached to the sprinkler pump. Give the final answer in the unit of H. (9 marks) P=1,Q=20,R=5