TWI Industrial Member Report Summary 1025/2012
By R Sanderson
Background
Guided wave inspection has the advantage of providing full volumetric coverage of tens of metres of pipe from a single test location; however, guided wave behaviour is complex. There are many factors to consider such as the numerous possible vibrational modes, dispersion and multiple reflections. The guided wave inspection technique is potentially immensely valuable for unpiggable sections of pipeline such as at cased road crossings. However, in situations such as this, there are often bends in the pipe and the presence of the bend is known to distort the received signals, particularly in tight bends. In order to address this issue, a study has been carried out that uses a combination of finite element analysis and experimentation to understand the behaviour of guided waves in a relatively tight pipe bend example. The work presented here builds upon work carried out by others and in past TWI core research programmes (Sanderson et al 2003a, 2003b, 2007, 2008 and 2009).
Objectives
- Use finite element modelling to investigate the behaviour of guided wave propagation around pipe bends.
- Experimentally validate the finite element results.
- Develop a technique for correction of the signal distortion caused by propagation around a bend.