Stress Analysis of Riser using Finite Element Method (FEM)

This report basically discusses the preliminary research done and basic understanding of the
chosen topic, which is Stress Analysis of Riser using Finite Element Method. The objective of
the project is to perform static stress analyses for selected load cases on riser. There are two
types of load which acting along the riser structure, environmental and functional load.
Environmental load is due to wave and current of the sea water whereas functional load is due to
te111perature and pressure of oil/gas carried by tile riser. These loads can cause global buckling
and failure to the riser. Thus, the study is about to determine the generated stress along riser due
to these loads to ensure that the detailed design of riser safe for operation. Static stress analysis is
the core of the riser design. The challenge in this project is to understand the stress generated
whe11 load is applied 011 riser ll!ld also to model the real structure of riser itself. Basically, the
scopes of study are about effect of environmental and functional load on rigid riser and Finite
Element analysis using ANSYS. Several theories have been adapted to complete the study. The
theories include One-seventh power law, Morrison Equation and stresses equation. Methodology
of this proj(.lct started with project identification, followed by data gathering and calculation of
hydrodynamic forces. After calculation is done, ANSYS is used to conduct modeling. While
modeling, steel X65 and two element types are chosen to model the riser. Based on the
simulation result, comparison will be done between generated stress from ANSYS and calculated
allowable stress. The acceptance criteria for stress analysis based on PTS 20.214, generated
stress must less than allowable stress.