Overview of Structural Health Monitoring Process Dr. K. Gopikrishna Assistant Professor, Department of Civil Engineering, NIT Warangal. SHM ProcessK.Gopikrishna, CE5265 Overview ofSHM for Civil Engg Applications LearningaboutIn-serviceconditionof structureusingtechniques,devicesand systemsthataretraditionallydesignatedas NDT and NDE tools. Goal NDT /NDE normally referes to onetime assessment of condition of materials in the structure using equipment external to the structure. 1. SHM referes to activities focussed on assessing the condition of the structure or its key components based on response to various types of loads. 2. Ongoing or repeated assessment of the response by embeding or attached to the structure during monitoring period. SHM is applicable to all types of Civil Engineering structures includingbridges,buildings,tunnels,pipes,highwaysand railways. K.Gopikrishna, CE5265 Overview ofSHM for Civil Engg Applications Typical Flow pattern between the components Conversion of Data into Structural responseCategories of SHM SHMcanbeclassifiedintooneofthefour categories&Subcategories,distinguishedbythe type of test In terms ofhow data is collected physically Timescales over which data is obtained. 1. Static Field testing 2. Dynamic Field Testing 3. Periodic Monitoring and 4. Continuous Monitoring K.Gopikrishna, CE5265 Overview ofSHM for Civil Engg Applications K.Gopikrishna, CE5265 Overview ofSHM for Civil Engg Applications K.Gopikrishna, CE5265 Overview ofSHM for Civil Engg Applications Classification of SHM-level of sophistication and types of information Basic level of SHM,capable of detecting the damage but cannot provide any info regarding nature , location and sevearity of damage. & also cannot assess Safety Slightly sophisticated, Detect Pinpoint Damage and provide some indication of severity More Sophisticated, detailed info, can be used to evaluate safety of system Complex and costly class K.Gopikrishna, CE5265 Overview ofSHM for Civil Engg Applications Decreased ongoing inspection and maintenance costs Increased safety and improved understanding of behaviour and durability of monitored structure. Improved understanding of In-situ behaviour Informationusedinthecodesofpracticeresultfromresearchprogrammes conducted at Sophisticated Structural Engg Laboratories around the world. Difficult to model the actual behaviour of fullscale structures insitu- experimental analysis is carried out. Generally small scale specimens are used which are representative of only small portion sof the structure subjected to Idealized loads. Inservice Monitoring provides wealth of information on really how the structure behaves when subjected to structural and environmental loads. This is the criticall info for future practice of structural Engineering. Early damage detection Preventsthestructurefromhavingtosustaintheloadsforextendedperiodsof time in damaged state. Allowsrepairtobemadeattheonsetofdamagewhichcandrasticallyreduce repair costs an dprevent future deterioration [Pines et al.2002] Advantages/benefits for CE Systems K.Gopikrishna, CE5265 Overview ofSHM for Civil Engg Applications Assurances on structures Strength and serviceability ImportantforLongspanbridges,wherevisualinspectionareinadequatefor determining bridges safety. SHMcanbeusedwheredataisneededtoprovideconfidenceinanew buildingmaterial or in an innovative construction technique. Incase of structure nearing its life time,SHM may permit it s continued use for a time by providing confidence of its performance. Reduction in Down time During structural repair or upgrade works-major cost needs to to be condidered in assessing whole life cost effectiveness of infrastructure system. Includecoststosocietyduetolossofproductivity,economicgrowth, inconvenience costs and Energy costs. Thesecostsmustbeconsideredduringrehabilitationandupgradingschemes where early damage detection and improved understanding of structural behavior result in reducing down timefor structures which require repair/strengthening. ImprovedMaintenanceandManagementstrategiesforbetterallocationof resources. Reducetherequirementoffieldinspectionandenabledevofinfrastructure condition databases which be automatically updated. Decisionmakerscanformulatebetterstrategiestoeffectivelydealwith Infrastructure deterioration . K.Gopikrishna, CE5265 Overview ofSHM for Civil Engg Applications What is Monitored, How & Why Background of Structural Dynamics necessary for Diagnostics Prerequisite for the course. Next Lecture K.Gopikrishna, CE5265 Overview ofSHM for Civil Engg Applications