Resilience of critical national infrastructure

THE CHALLENGE

Our client needed to assess critical components of a new facility against potential threats from terrorist attacks, accidents and other extreme events. The consequence of such events required the facility to be assessed against loads such as explosions, aircraft crashes and impact from fragments at high speed.

OUR SOLUTION

In order to meet our client's need for such a wide ranging assessment, Frazer-Nash developed an analytical approach involving the use of validated finite element models using the explicit analysis code LS-DYNA. The use of LS DYNA meant the full range of potential threats to the structure could be assessed using the same model, reducing the time and cost needed to produce the results.

We examined a number of explosion threats that might act on and within the structure. We explicitly modelled the detonation and blast propagation and the models included consideration of structural damage as a result of these loads.

The work also involved the development of a finite element model of a number of aircraft chosen to represent various impact threats. This model was configured to accurately represent the load a target would be subjected to during an aircraft crash. It was validated by comparison to public domain impact data from full scale aircraft tests. Similar analyses were also performed to examine the effect of impact from civilian airliners and light aircraft.

THE BENEFITS

Performing an analytical assessment on the structure allowed our client to undertake a thorough review of the structural design of their facility. The use of validated finite element modelling allowed a much wider range of load conditions to be analysed, without the need for complex and expensive testing. The results of the analyses were used to inform design changes and acceptance of the facility against the resilience and security requirements.