నైరూప్య

Structural Health Assessment and Monitoring - A Global Outlook

Achintya Haldar

Extensive use of sophisticated and extensive infrastructures all over the world reflects the advanced nature of our civilization. The major research interest at present is to make them more environmental friendly. Obviously, it will be implemented mainly on new constructions. However, the states of existing infrastructures is very alarming.  Some of them are functionally deficient, over their design life generally considered to be about 50 years, and may not satisfy our current needs or design requirements. Some of them need to be replaced immediately or in the near future.  Unfortunately, we do not have resources to replace them or we need to prioritize them in order of urgency of replacement. Due to the unavailability of the resources, one attractive option will be to inspect them and make appropriate maintenance decision in terms of do nothing, inspect more frequently, repair, or replace them at the earliest possible time. 

The urgency and seriousness of the problem attracted multidisciplinary research interests. The author identified the problem in the early nineties. The society demands that the structural health assessment and monitoring (SHAM) procedure should be based on the behavior of the current state; not when it was designed. The procedure should identify locations of defects at the local element level and their severity since all defects are not equally important.  Also, they should be non-destructive in nature without disrupting their normal operation. If responses need to be measured, they are expected to be noise-contaminated, particularly in the field condition. Any algorithm should be capable of incorporating such contamination information. For large infrastructures, it may not be possible or economically prohibitive to instrument the whole structure. It will be very desirable if the infrastructures are instrumented locally and responses are measured only in them.