Uniform pressure and uniform wear are two basic conditions or assumptions that may occur at interface of the friction surfaces.
The designer must decide on which assumption more closely approximates
the particular clutch or brake being analyzed.
The uniform-wear assumption leads to lower calculated clutch
or brake capacity than the assumption of uniform pressure, as observed in Example 13.4. Hence, disk clutches and brakes are ordinarily designed on the basis of uniform wear that gives conservative results.
The preceding analysis can be used as a guide.
Design considerations also include the characteristics of the machine whose brakes or clutches are to be a part and the environment in which the machine operates.