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Car Brake Performance Using Disc-Brake Variations

  1. Feb 19, 2007 #1
    Hi all,

    Im a Mech Eng student getting my 3rd year project underway,

    Using a simple ABS Disc Brake system model, i would like to analyse braking performance for calculations obtained with variations of brake pad size, mateial, and also different disc sizes and materials.

    My question is...if i were to use simulink/matlab, which models systems with rates of change,

    what factor could i analyse to predict braking performance?

    My suggestion is to monitor the rate of heat dissipated when force is exerted on the disc from the pad friction material. Would a higher rate of heat dissipation mean better overall braking? or is there a better way to analyse this part of the brake system?

    I have all the model equations for each component ready, but im stuck with what basis to make my analysis.

  2. jcsd
  3. Feb 20, 2007 #2
    The main reason to dissipate heat is that metal (Or worse with ABS) rapidly reach a temperature where they structurally fail.
    Citreon and Peugeot disks are reknown for warping under heavy but not unexpected use.
    I have always written my own Matlab modules as I it is easier to add in additional factors as you go along.
    By building an incremental model you can start with friction, force, velocity and then add in affects of heat on the coefficient of friction, Disk thermal mass and terminal temperature etc as you go along.
    Remember that different materials act in different nonlinear ways, e.g. carbon fibre braking systems are poor at low temperatures but actually get better with heat before suddenly dropping off.
  4. Feb 20, 2007 #3
    hi panda,

    thanks for your input, indeed, the model would be built in a compound fashion, starting with the speed one is travelling, to the force exerted by the drivers foot. Desirably i would like my model to end with the force exertion on the discs and its effects. My problem is that everytime ive used matlab/simulink (which im a beginner in) i would have a system comprising of e.g xdot = (2k + b1 + 3....)/m etc.
    so im assuming i will need a similar equation for rate of friction over braking time, and rate of heat disipation over time....

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