ABSTRACT
This chapter presents the total strains of plies embedded in hoop-chop laminates used in sanitation pipes. The computed total strains enter directly in the unified equation to estimate the laminate load-dependent durability. To facilitate the mathematical manipulation the ply strains are computed numerically from arbitrarily chosen laminate constructions and the final design is established by trial and error. The structural contribution from three distinct plies – unidirectional, sand core and chopped fibers – complicates the design equations, which become too lengthy and unwieldy. The computed numerical total strain components cannot exceed the allowable values. The entire process is repeated for a different laminate until a satisfactory solution is found. The residual hydric and mechanical strains are computed for the same chosen laminate construction. The hoop-chop sanitation pipes usually work underground with the soil friction absorbing all longitudinal movement.
