Thermal Strain of Pipes Composed with High Strength Polyethylene Fiber Reinforced Plastics at Cryogenic Temperatures
High strength polyethylene fiber (Dyneema® fiber; hereinafter abbreviated to DF) has a large negative thermal expansion coefficient. Several kinds of pipes were prepared by means of filament winding or sheet winding method. The thermal strain or residual stress of those pipes were measured at liquid nitrogen temperature. The thermal strain was also calculated and was compared with the measured values. The circumferential thermal strain of the inner surface was found to be much different from that of outer surface. The circumferential strain changed with the ratio of inner diameter to thickness of pipes. The mean thermal strain of inner and outer surface was found to agree well with that of calculated value. It was confirmed that the negative thermal expansion can be realized even in the pipes. The design methodology of the pipes with negative thermal expansion was discussed.
KeywordsResidual Stress Thermal Strain Circumferential Strain Thermal Contraction Negative Thermal Expansion
Unable to display preview. Download preview PDF.
- 6.T. Kashima, S. Nishijima and T. Okada, Cryogenic material using high strength polyehtylene fiber, 44th Meeting on Cryogenics and Superconductivity, 245(1991)Google Scholar