Full scale 4-point bend setup of pipes

Full scale bending with internal pressure of a ball joint pipe.

Features:

  • Varying internal water pressure between 32 and 64 bar at 0.5 Hz pressure frequency.
  • Outer support distance of 4800 mm and inner support distance of 1200 mm.
  • Maximum vertical bending load up to 1500 kN.
  • Maximum bending angle of 15° at each side (30° in total) measured with 2 inclinometers.
  • Strain measurements by means of strain gauges and Digital Image Correlation (DIC)

Application:

Old pipelines used a ball joint to introduce a bend in the pipeline. The ball joint was positioned at the desired angle and welded together.

Objective:

Determination of the weakest position of the ball joint ( four-point bending = constant, maximum moment over the entire ball joint length) and assessment of the remaining (fatigue) lifetime with internal pressure.

Media

Manufacturing of the protective casing for the Full scale 4-point bend setup of pipes
Full scale 4-point bend test specimen
Full scale 4-point bend test specimen DIC
Full scale 4-point bend setup overview