Structural Health Monitoring for Limit States Other Than "Failure"

Abstract:

This presentation will cover applications of instrumentation and monitoring of in-service structures to understanding, quantifying, and mitigating challenges related to limit states other than catastrophic failure due to insufficient strength or stiffness. Such non-catastrophic limit states include various forms of serviceability limits, from the familiar floor deflection provisions in building codes to dynamic compatibility considerations between processing piping and structural elements in industrial plants, durability and service life considerations, and preservation of essential ancillary structural elements such as fireproofing and building envelope materials. Structural adequacy against these limits may be compromised by endogenous factors such as material degradation (corrosion, alkali-silica reactivity) or by exogenous factors such as changes in service loads or beyond-design-basis events. Judiciously selected instrumentation and appropriate monitoring schemes can provide insight into the behavior of structures with respect to these limits and thus help (1) reduce uncertainty in the ability of the structure to perform as desired, and (2) inform retrofit or rehabilitation efforts if required. These instrumentation and monitoring approaches will be discussed in the context of case studies from transportation, industrial, and specialty structures.

Biography

NU Civil Engineering alumnus David Kosnik (MS 2009, PhD 2012) draws from his dual background in civil and computer engineering to develop innovative performance monitoring and evaluation solutions for in-service infrastructure. His experience includes both long-term, continuous remote monitoring and short-term tests of occupied buildings, in-service bridges and structures, industrial facilities, movable structures, structures subject to ground vibration, and infrastructure vulnerable to hydraulic and geo-hazards. Dr. Kosnik's monitoring strategies link measured quantities to specific limit states or performance metrics to support infrastructure management decisions, particularly those related to risk management, beyond-design-basis events, evaluation of retrofits and life extension efforts, characterization of damage progression, and early warning of possible disruption.