BEHAVIOR OF FIRED‐CLAY RING SECTIONS UNDER LOAD*

A bstract The advent of the electric strain gauge has made it possible to study the behavior of ceramic materials under load, and their stress‐strain relations may be determined with exactness. Earlier work by Lassettre and Everhart has shown that ceramic materials are elastic and that mathematical and engineering formulas may be applied to their use. This paper is concerned with the theoretical analysis of stresses in ring sections and with the behavior of fired ceramic ring sections, such as sewer pipe and drain tile, under stress. Data are presented which show that fried ceramic pipe almost precisely follow the behavior predicted from theoretical calculations such as those first presented by Talbot in 1908. A new precise equation for calculating relations between diameter, wall thickness, and strain is presented, and the validity of shorter semiempirical formulas commonly used is examined in the light of the more precise knowledge. Examples of the use of these mathematical formulas for changing relationships between diameter and wall thickness are given. Some manufacturers of sewer pipe have already changed their dies to give the different relationships, with successful results.