ABSTRACT
Stress failures of flexible pipes by bursting are analyzed in Chapter 2. Wall crushing is analyzed in Chapter 6. For these cases, reconstruction of failure is simple. Not so simple is the reconstruction of a rigid pipe failure. Under some conditions, flexible pipes fail as rigid pipes. For example, bursting of a flexible pipe sometimes occurs so suddenly as to cause brittle fracture instead of plastic yield. Water hammer is often the cause. Bursting due to internal pressure may be affected by longitudinal stress and/or external loading. Failure usually occurs at a joint or an appurtenance where stresses may concentrate or where strength of material may be deficient. For purposes of design, analyses are based on simple mechanics of stress and deformation. But for failures, combined or c ompound stress analyses, with corresponding performance limits, may be required. In fact, stress theory is not the only theory for failure analysis. Nevertheless, questions about failure always seem to arise in terms of stresses and strains and performance limits for tri-axially stressed elastic materials. Better theories are becoming available for plastic and stress-regressive materials.
