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ASSAI Project Closes Successfully

Thu, 07 January, 2021

TWI was working as part of a consortium on the ASSAI Project to develop unmanned aerial systems (UAS) for the non-destructive evaluation of large civil infrastructure.

TWI worked alongside project coordinator Air Control Entech, JR Dynamics Ltd, the Brunel Innovation Centre and James Fisher Testing Services.

Unmanned aerial systems offer a reliable and safe solution for accessing difficult areas for the inspection and monitoring of large structures using thermal imaging cameras, and surveying and mapping technologies. However, critical inspections still required the use of human inspections in parallel with UAS, limiting the scope for productivity improvements and cost savings.

To address this challenge, the consortium developed an unmanned aerial system for advanced contact inspection (ASSAI). This system was initially created for use on civil structures such as bridges, but can be used to inspect a wide range of structures, providing significant productivity increases.

TWI developed a suite of software to support the optimisation of maintenance planning with the system. The software was created using risk-based inspection (RBI) concepts and included three distinct modules:

  • Module 1: Questionnaire-based bridge risk screening
  • Module 2: FEA add-on for component stress analysis
  • Module 3: Thinning damage focused RBI

Module 1 provided qualitative assessment to offer an overview of the risk level of a structure in order to approximate an inspection schedule. Module 2 identifies hotspots that need to be prioritised as well as an input parameter for detailed quantitative RBI assessment in Module 3.

In addition to the software development, TWI provided NDT consultancy services to the consortium.

A paper has been produced to provide details of this project, which you can access here:


The ASSAI Project has received funding from Innovate UK under number 104405

For more information please email: