SOLID LIQUID_patent

Apparatus for creep endurance testing structural components (pdf)

Patent US 4812052

Structural components, especially components having complicated configurations, are endurance tested for their creep resistance or strength in a removable massive metal testing block which encloses the component being tested in the manner of a mold. The mold type testing block is made of a high heat resistant metal acting as a susceptor in an induction heating system in which the testing block is surrounded by an induction heating coil. In this system the component being tested can be heated to high, highly constant temperatures which provides a substantial improvement in the creep testing results and reduces the cost of testing.

 The aim of studying the creep phenomena is to determine the behaviour of the polymer. Polymers have intrinsecally a double nature, that is liquid and solid at the same time. The liquid behaviour can be measured by the amount of creep, namely the (irreversible) elongation of the sample due to the constant stress applied. The solid behaviour is represented by the elastic response, e.g. reversible elongation.