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PROJECT ME-05:
ACTIVELY TUNED RESONATOR
Preliminary Design Report

Problem Statement

Design a surface-mounted device to actively dampen vibrations using smart rubber.

Background

Continental Tires is funding a project to research the effects of smart rubber to actively dampen vibrations. The smart rubber is a composite consisting of a silicon based elastomer and piezoelectric ceramics that can be adjusted using electric current. The elastomer is being used because of its ability to absorb force and spring back. It is made by combining three chemicals:

· Polydimethylsiloxane: [SiO(CH3)2)]n -- Elastomer Fluid
· Tetraethylorthosilicate: [Si(OC2H5)4] -- Crosslinking Agent
· Stannous-II Ethylexanoate -- Catalyst

The piezoelectric ceramics are being used because of there ability to deform when current is passed through them. They are compounds of lead zirconate and lead titanate. Our particular piezoelectrics are flat, rectangular in shape, and have dimensions of 1.572” x .784”.

Wired Piezo-Electric

Objectives

To successfully use the elastomer-piezoelectric composite to dampen the vibrations of the lumped masses in the system. We also hope to gain further knowledge and understanding of the properties of the elastomer and piezoelectrics as well as better understanding of vibrations and dampening effects.

Plan

We plan to research the necessary materials, both the elostomers and piezoelectrics, and using vibration theories design a system in order to test the dampening effects of the elastomer. After we design the system we will build and test the system to see if our designs work. After the testing we plan to do any necessary modifications to the system, and present our findings in some form to Continental Tire.

System

In order to build the system we must first mold the elastomer into the appropriate size
and shape for our system. In order to neglect the effect of the stiffness of the
piezo-electrics in the elastomer we will use the general engineering assumption
of a 10:1 ratio. Where as the height of the elastomer would be 10 times that of the
total height of the piezo-electrics. Our mold will be made of aluminum and will consist
of three pieces. It will have two haves separated by a parting line. This will allow us to
easily remove the composite once the mold has set. It will also have a top cap which will
suspend and secure the piezo-electrics into the elastomer.

Mold

We must also choose an appropriate size and shape for the beam, and masses in order to design the system for maximum vibration absorption. In order to achieve the desired results we will use vibration theories and the bases that the ratios of the stiffness of the beam to mass 1 and the stiffness of the elastomer to mass 2 must both be equal to the driving frequency of the vibration generator.

k1/m1=k2/m2=w

We will test the system using a function generator and accelerometers linked to the Pulse 5.0 program

Technology Impact Statement

Economic Impact

Possibility for new technology on the market. New technology may bring about the
need for new companies and more jobs. If implemented in new tires the technology
may increase the price of manufacturing thus increasing the price of tires.

Environmental Impact

The production of the elastomer involves the use of chemicals that may be very
harmful to the environment. If the elastomer goes into production some serious
consideration should be taken to ensure the protection of the environment.

Manufacturability

Manufacturing process consists of two parts. Designing and building the molds, and producing the elastomer and pouring it into molds. The production of these composites may be difficult due to the problems faced in trying to bond the piezoelectrics with the elastomer.

Sustainability

If the new technology is implemented into tires it has much potential for future uses. Even though the tires may be more costly, the elastomer composites may save consumers money in the long run by decreasing the wear on their vehicles as well as giving them a better ride.

Ethics

As long as there are no patents involving the uses of this type of elastomer composite
we see no ethical problems.

Health/Safety

The health and safety of workers producing this material should be taken into careful consideration. Not only should all of the chemicals be properly contained and disposed of, but also workers should be educated in the proper uses and dangers of the chemicals involved.

Societal Impact

If our tests our successful there could be much possibility for development of new and innovative technologies in many fields other than tires.

Political

No present campaign has anything to do with this project.