The benefits of using AE are many, but primarily it is the information gained by an ability to monitor 100% of the structure and locate damage initiation as it occurs, long before it becomes structurally significant. This means that the structural test programmes can be carefully controlled, reducing costs and expensive failures. Information on damage development is essential for design purposes and to know the effects of accidental over-stressing of a structure. Sensors are now being installed on aerospace structures for whole-life continuous monitoring, detecting both impacts and the resulting damage. Physical Acoustics provides services, dedicated instrumentation and training.

 

 

Left The Experimental Aircraft Programme (EAP) was the prototype for Eurofighter. On this and similar CFRP structures during static test, BAe claimed prediction of ultimate failure at 50%-70% of failure stress.

 

Centre The fin on the SAAB/BAe JAS-39 Gripen under test. The AE sensors provide essential information on damage development as well as protecting the structure from accidental over-stress. A 78-channel PAC Spartan system was used to monitor the entire aircraft CFRP wing and tail. Technology transfer, procedures and training of SAAB operators was provided by Physical Acoustics Limited.

 

Right The ARIANE SPELDA is a 4 metre carbon fibre skin aluminium honeycomb structure. Since 1983 Physical Acoustics have monitored development and production structural tests to check the bonded joints and the composite structure integrity.