Assessment Brief 4 Student Name/ID Number Course BTEC HNC in General Engineering Unit Number and Title 8: Mechanical Principles Academic Year 2020/21 Unit Tutor Philip Arnold Assignment Title Number 4...

they've requested to have all the workings out in depth, as this is a problem based assessment.


Assessment Brief 4 Student Name/ID Number Course BTEC HNC in General Engineering Unit Number and Title 8: Mechanical Principles Academic Year 2020/21 Unit Tutor Philip Arnold Assignment Title Number 4 Natural and damped vibrations within translational and rational mass-spring damped systems. Issue Date 25th May 2021 Submission Date 16th June 2021 IV Name & Date Allocation of time to complete assignment Part 1 is a written explanation which must include formulas / equations and diagrams to ratify your written explanation. Part 2 is a calculation & written explanation type problem. You MUST show all formulas and workings throughout, underline your sub answers with red lines and highlight your final answers in pink or yellow so are easily identifiable. At the top of every page you must type your: Name – Student ID – Qualification – Assignment number. Submission Format This is a written & problem based assessment. To evidence that you have met the criteria: · The written reports must be at least 200 words. · Must show working out · Use the correct units of measurement · And use formulas right through. Remember, answers are only part of the solution. You must show how you got there and be able to document and communicate your problem solving technique. Some higher criteria questions will draw on you to interpret, compare and draw conclusions of worked solutions. Format: Part 1 is an explanation written type question. Part 2 is a calculation. And written explanation problem. Where references are used, follow Harvard Referencing System including in-text citations. Student declaration I certify that the work submitted for this assignment is my own and research sources are fully acknowledged. Student signature: Date: Unit Learning Outcomes LO4 Analyse natural and damped vibrations within a translational and rotational mass spring system. Assignment Brief and Guidance Scenario You are employed in the R&D dept of an major Defence company. You are part of the team involved in designing a new Nuclear powered submarine. To avoid detection it is imperative no sound is emitted form the hull of the submarine which could be detected by an enemy submarine, surface ship or aircraft using sonar buoys. Even though the hull is covered in sound absorbing rubber tiles and the propeller blade has been designed to avoid cavitation The internal machinery such as air conditioning, pumps for circulating water to the electrolysis system and pumps to pass pressurised water around the nuclear reactor and the main propulsion motors needs to mechanically isolated from the hull to aid noise elimination. Some equipment is mounted on rubber blocks, some on steel springs due to the weight and torque involved. As motors and pumps are rotation devices, and gravity acts on the body of them two types of forces are involved. The rotating components can cause Simple Harmonic motion, and the mass of the components vertical harmonic motion also known as Harmonic resonance. You must explain how the natural frequency of vibration affects this This resonance is dangerous for many reasons. Some of which are :- Metal fatigue, Can penetrate some materials which have the same harmonic resonant frequency, or third or fifth etc harmonic characteristics and escape the hull. Part 1. You are tasked with compiling a written technical report explaining with the aid of diagrams and equations the:- ( a ) Nature of the problem. Part 2 A pump of mass 150 kg is suspended by 10 springs. A simulated SCRAM or in Russian” Avariynaya Zashchita 5-y kategoriisituation “ was performed on a live test bed and the pump was found to be displaced through a distance of 45mm subsequently oscillating “ Bouncing “ 90 times in 80 seconds. You must determine:- ( a ) The periodic time ( b ) The stiffness of the spring. ( c ) The time taken for the first motion through a displacement of 25mm ( d ) The velocity at this point. ( e ) give a written explanation of what measures can be employed to reduce the oscillations in both amplitude and frequency Resources Textbooks Pearson Higher Nationals in Engineering Core Text Book John Bird & Carl Ross, Mechanical Engineering Principles, Fourth Edition, Routledge. ISBN 978-0-367-25324-0 BOLTON, W. (2006) Engineering Science. 5th Ed. London: Routledge. TOOLEY, M. and DINGLE, L. (2012) Engineering Science: For Foundation Degree and Higher National. London: Routledge. Journals International Journal of Engineering Science. Learning Outcomes and Assessment Criteria Pass Merit Distinction LO4 Analyse natural and damped vibrations within translational and rotational mass-spring systems P9  Explain the natural frequency of vibration in a Mass-spring system. M4 Determine the amplitude and phase angle of the transient response within a mass spring damper system. D4 Identify the conditions needed for mechanical resonance and measures that are taken to prevent this from happening.