Condition Monitoring (CM)  Structural Health Monitoring (SHM) a joint lecture for MECH 512: Design for Structural Integrity MECH 513: Smart Materials and Intelligent Structural Systems John Summerscales

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). 

Condition Monitoring (CM) Taylor [2006] 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.

Condition Monitoring (CM) Techniques that can be used include: the Human Senses look, listen, smell, taste, feel etc. Motor Current Analysis Oil Analysis and Tribology Non-destructive testing (NDT)

Condition Monitoring (CM) Lloyd’s Register’s integrated condition monitoring service (ICMS) [2] proposes that "integrated condition monitoring helps optimise maintenance by judging the health of machinery using non-invasive sensing technology". 

Condition Monitoring (CM) The benefits of an ICMS approach are: early detection of impending machinery failure to help lower the risk of unscheduled downtime scheduling and utilisation of maintenance resources is more efficient reductions in time spent in dry dock, if a pre-dry-docking fault locating survey is performed reduced likelihood of ‘maintenance induced’ failures availability of global condition monitoring data.

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. 

Risk assessment Consider the Probability (likelihood) and the Severity (consequence) of failure separately. classify them either as a range or simply as low/medium/high the risk is the product of the two numbers a high number is a high risk endeavour to reduce the calculated risk

Probability of Failure Risk assessment  Consequence of failure Low Medium High Probability of Failure HIGH RISK LOW RISK e.g. http://www.tech.plym.ac.uk/sme/MATS324/risk.htm

Condition Monitoring (CM) So how might we monitor that: the mp3 player has enough power now, and for five hours time the washing machine is consuming the minimum power needed and , if not, where the additional load is being taken that the car will continue to run smoothly that the car tyres are at the correct pressure

Condition Monitoring (CM) The options might include: voltage and current measurement noise and vibration the instrument panel in-wheel pressure sensors

ISO/DIS 18436-4 Condition monitoring and diagnostics of machines - Requirements for training and certification of personnel 1: certifying bodies and the certification process 2: vibration condition monitoring and diagnostics 3: training bodies and the training process 4: field lubricant analysis 6: acoustic emission 8: thermography

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. 

Structural Health Monitoring (SHM) So how might we monitor: an earth filled masonry arch bridge carrying a road or railway cracking at joints in an offshore oil exploitation rig jacket corrosion of a liquid storage tank while full of hazardous chemicals barely visible impact damage (dropped tools on CFRP aircraft wings)

Structural Health Monitoring (SHM) The options include: mechanical/dead-weight loading with measurement of deflections modes and frequencies of vibration embedded sensors non-destructive testing technologies (MATS324 lecture A12) ...