Non Destructive Inspection

In NDT commonly known as Non destructive testing, there are many techniques used to determine the properties of a structure or material. In NDT, one of these techniques involves the structure undergoing a dynamic input such as a hammer or a controlled impulse. Key properties such as displacement or acceleration at different points of the structure are measured as the corresponding output. This output is recorded and compared to the corresponding output given by the transfer function and the known input. Differences may indicate an appropriate model which may alert engineers to unpredicted instabilities or performance outside of the tolerances, failed components, or an inadequate control system. Structures can be complex systems that undergo different loads during their lifetime. Some complex structures such as turbo machinery in a liquid fuel rocket can cost millions. Engineers will model these structures as coupled second order systems, approximating dynamic structure components with springs, masses and dampers. These sets of different equations can be used to derive a transfer function that models the behaviour of the system,