The background photo shows the bending test for 12-inches steel pipes in action, explains Annemiek Hilberink (MSc), who works with Heerema Marine Contractors. She used the massive set-up to study the bending effect of 80-tonnes of force on lined pipes. The bending simulates the winding of steel pipes on 16-meter diameter reels situated on the back of a ship. This method of pipe-laying for offshore oil and gas is preferred, because the critical welding of the pipes can be done onshore. However, reeling can easily damage the lined pipes, which are made of 17-millimeter thick steel outer layer, lined with 3-millimeters of stainless steel, in order to protect the pipe from corrosive acids in the transported crude. When the pipe is too thin, the inner mantle could wrinkle. Hilberink’s PhD research involved both physical tests and the mathematical modeling of bending lined pipes. Her cover shows the lab, photographed by her brother in law, and a bent pipe-section with an overlay of the calculated stresses, photoshopped by her husband.
Annemiek Hilberink, ‘Mechanical Behaviour of Lined Pipe’, 19 December 2011, PhD-thesis supervisors Prof. Frans Bijlaard (CEGS) and Prof. Bert Sluys (CEGS).