An Experimental Study on Mechanical properties of P110S under Dynamic Loads

Abstract

Oil country tubular goods (OCTG) may develop plastic bending, fracture and fatigue failure during the service due to dynamic loads, such as perforation impacts and fluid-induced vibration. This paper was to evaluate strength safety of OCTG under dynamic loading. To gain key parameters of the dynamic constitutive model of materials represented by Johnson-cook. An axial tensile test of the common P110S and an experiment on its mechanical properties under high strain rate were carried out for the first time. The yield limit of P110S under static loads was 775MPa, which was 2.2% higher than the nominal value (758MPa). The ultimate strength was 835MPa and the yield ratio was 1.08. Since it often requires the yield ratio higher than 1.2 5, the P110S had slightly poor tenacity. Under the strain rates of 500s-1 and 1000s-1, the yield limits of P110S were 15.5% and 41.4% higher than the static measured values. The dynamic loading experiments of P110S under the strain rates of 500s−1 and 1000s−1 were corresponding to the fluid-induced vibration of columns and perforation i mpacts-induced vibration of columns, respectively. Dynamic factor of P110S was determined according to engineering habits. According to conversion and contrast analysis on increment of yield limit under dynamic loading, the final strengths were decreased by 4.5% and 8.6%, respe ctively. Moreover, key parameters of the Johnson-cook dynamic constitutive model of P110S material were determined through experiments for the first time. They could provide key para meters of constitutive model for accurate finite element simulation analysis under dynamic loa ds.