Static Deflection Control of a PVC Pipe Joint Using Piezoelectric Actuation

This paper investigates the use of surface bonded piezoelectric induced strain actuators and their effectiveness at inducing deflection in a PVC (polyvinyl chloride) simply supported adhesively bonded pipe joint structure. The purpose using piezoelectric actuation is to reduce the high shear stress concentrations at the ends adhesive layer by reducing the joint end deflections caused by external loading; effectively enhancing the strength of the joint. Euler-Bernoulli beam theory is implemented to derive the elastic curves for two possible surface bond scenarios; on the pipe joint itself and on the separate spans of piping. The derived equations account for the physical and geometrical parameters of the piping and piezoelectric actuators. The effects of reducing the detrimental effects of a distributed external load caused by the weight of the fluid within the piping system are examined. A numerical study is carried out to evaluate the effectiveness of the piezoelectric actuation based on the two proposed actuator bond scenarios. Bonding two pairs of actuators on separate pipe sections was shown to be capable of inducing greater joint end deflections than bonding a single pair of actuators on the pipe joint. Bonding two pairs of actuators on the separate sections of piping was shown to be capable of reducing joint end deflections caused by external loading by 70%, while bonding one pair of actuators on the pipe joint was shown to be capable of reducing joint end deflections by 20%.