Numerical prediction of material properties and structural response of JCO-E offshore pipes
The present paper presents the application of advanced finite element tools to predict the influence of cold-forming on material properties and collapse resistance of steel JCO-E pipes. Results are obtained for a thick-walled 30-inch-diameter pipe, corresponding to diameter-to-thickness ratio value less than 20. The numerical simulations are supported by experimental tests determining the material properties of steel pipe and steel plate, which are used for forming the JCO-E pipe, and accounts for the influence of heat-treatment on pipe material and its effects on collapse capacity is discussed. The numerical results are also correlated with recent full-scale collapse experiments performed in C-FER, while both experimental data and numerical results are compared with the DNV-ST-F101 standard predictions, and suggestions on the value of fabrication factor are made, considering the material strength recovery due to heat treatment. Finally, the influence of heat treatment on material strength recovery and the collapse capacity is discussed.