Presentation on theme: "Condition Monitoring (CM) Structural Health Monitoring (SHM) a joint lecture for MECH 512: Design for Structural Integrity MECH 513: Smart Materials."— Presentation transcript:
1 Condition Monitoring (CM) Structural Health Monitoring (SHM) a joint lecture for MECH 512: Design for Structural Integrity MECH 513: Smart Materials and Intelligent Structural SystemsJohn Summerscales
2 Condition Monitoring (CM) Condition monitoring is the use of advanced technologies to determine the condition of equipment and predict its failure. This in turn should inform predictive maintenance (PM) or reliability-centred maintenance (RCM).
3 Condition Monitoring (CM) Taylor  has suggested that "just as your physician uses a variety of tests and evaluations to assess your state of health, we should do the same for our machinery“.There are six steps to a healthy machine:what are the possible failures?which of these failures are significant?how can we avoid these failures?if we can’t avoid failure, can we get an early warning?select a suite of tests to detect early warning signs.collect the results of the tests at one decision point.
4 Condition Monitoring (CM) Techniques that can be used include:the Human Senseslook, listen, smell, taste, feel etc.Motor Current AnalysisOil Analysis and TribologyNon-destructive testing (NDT)
5 Condition Monitoring (CM) Lloyd’s Register’s integrated condition monitoring service (ICMS)  proposes that "integrated condition monitoring helps optimise maintenance by judging the health of machinery using non-invasive sensing technology".
6 Condition Monitoring (CM) The benefits of an ICMS approach are:early detection of impending machinery failure to help lower the risk of unscheduled downtimescheduling and utilisation of maintenance resources is more efficientreductions in time spent in dry dock, if a pre-dry-docking fault locating survey is performedreduced likelihood of ‘maintenance induced’ failuresavailability of global condition monitoring data.
7 Condition Monitoring (CM) Risk-Based Inspection (RBI)a method for deciding which components to inspect. instead of a fixed inspection interval, RBI considers the risk of an item of plant, or of a component, failing and decides the inspection interval on that basis.
8 Risk assessmentConsider the Probability (likelihood) and the Severity (consequence) of failure separately.classify them either as a range or simply as low/medium/highthe risk is the product of the two numbersa high number is a high riskendeavour to reduce the calculated risk
9 Probability of Failure Risk assessment Consequence of failureLowMediumHighProbability of FailureHIGH RISKLOW RISKe.g.
10 Condition Monitoring (CM) So how might we monitor that:the mp3 player has enough power now, and for five hours timethe washing machine is consuming the minimum power needed and , if not, where the additional load is being takenthat the car will continue to run smoothlythat the car tyres are at the correct pressure
11 Condition Monitoring (CM) The options might include:voltage and current measurementnoise and vibrationthe instrument panelin-wheel pressure sensors
12 ISO/DIS Condition monitoring and diagnostics of machines - Requirements for training and certification of personnel1: certifying bodies and the certification process2: vibration condition monitoring and diagnostics3: training bodies and the training process4: field lubricant analysis6: acoustic emission8: thermography
13 Structural Health Monitoring (SHM) a damage detection process used for aerospace, civil and mechanical engineering infrastructure which monitors the system over time. typically, an array of sensors collects dynamic response measurements either continuously or at regular intervals.
14 Structural Health Monitoring (SHM) So how might we monitor:an earth filled masonry arch bridge carrying a road or railwaycracking at joints in an offshore oil exploitation rig jacketcorrosion of a liquid storage tank while full of hazardous chemicalsbarely visible impact damage (dropped tools on CFRP aircraft wings)
15 Structural Health Monitoring (SHM) The options include:mechanical/dead-weight loading with measurement of deflectionsmodes and frequencies of vibrationembedded sensorsnon-destructive testing technologies (MATS324 lecture A12) ...