Axial Tensile Ultimate Strength of an Unbonded Flexible Riser Based on a Numerical Method.

Unbonded flexible risers consist of several helical and cylindrical layers, which can undergo large bending deformation and can be installed to different configurations to adapt to harsh marine environments, and is a key equipment in transporting oil and gas resources from Ultra Deep Waters (UDWs) to offshore platforms. The helical interlayer of an unbonded flexible riser makes the structural behavior difficult to predict. In this paper, the axial tensile behavior and the axial tensile ultimate strength of an unbonded flexible riser are studied based on a typical 2.

Syntheses of a perfluoroethanesulfonyl fluoride vinyl ether.

The target monomer, perfluoroethanesulfonyl fluoride vinyl ether 8, was obtained from the starting material, iodoperfluoroethanesulfonyl fluoride 1, through the intermediate, acyl fluoride 4. Two different synthetic routes were utilized in the conversion of 4 to 8.