Viscoelastic modeling of press-fitted composite cylinders

Interference stress is an important design factor for press-fitted cylinder applications such as flywheels and pressure vessels, which may decrease over a period of time. Stress relaxation and creep in press-fitted composite cylinders are investigated based on anisotropic viscoelasticity. The analysis accounts for ply-by-ply variation of material properties and fiber orientations through the thickness of cylinders. Viscoelastic characteristics of press-fit composite assemblies are quite different from those of isotropic cylinders, due to the extreme anisotropy of composite materials. Results show a significant change of interference stresses over a period of time, which is critical to structural performance and durability.