Vibration analysis diagnostics Escola Superior Náutica Infante D. Henrique

Vibration analysis diagnostic techniques make it possible to reduce maintenance costs by preventing interruptions or breakdowns in a wide range of equipment.

Vibration analysis is a robust and proven technique which, by detecting anomalies or developing faults, makes it possible to anticipate breakdowns or validate the need to carry out predetermined (preventive) operations or corrective interventions. It requires a comprehensive and precise approach, based on a systematic and structured characterisation of equipment and operations with supporting mathematical models and appropriate standards.

This microcredential aims to present and characterise the fundamentals of vibration analysis diagnostic techniques, as well as how to materialise them into inspection plans. From this perspective, the most common operating faults and irregularities and the methodologies for assessing and validating them are presented.

The course is organised as a level 5 micro-credential in the European Qualifications Framework, with 4 ECTS (45 contact hours) and a certificate is awarded on passing the assessment activity.

Attendance regime
The course will take place face-to-face during the post-work period. It is planned to take place in 11 sessions of 4 hours and 1 hour for assessment (written test).

Tuition, fees and emoluments: 370€

Notice

T1 - General notions (4 hours}

Vibrations-representation in time
Simplification by harmonic functions. Notions of period, frequency and angular frequency.
Representation in displacement, velocity and acceleration, and their conversion
Global values of amplitude, peak value, peak-to-peak value and effective value (RMS)
Frequency representation, frequency spectra.
Fourier analysis. Conversion of signal in time to frequency.

T2-Vibration modelling with a 1 degree of freedom system (4 hours}

Mass-spring model, characteristic equation, components of the dynamic system m, k and c
Solution of the equation of motion-vibration in the free regime, concepts of natural frequency and critical damping
Excitation functions and equation of motion of vibration in forced regime, resonance phenomenon and dynamic amplification coefficient. Determination of damping.
Transmission of motion and forces, transmissibility
Frequency-dependent excitation functions and implications for dynamic response.

T3-Vibration modelling with a system of n degrees of freedom (4 hours)

Modelling - equations of motion. Matrix representation, mass, stiffness and damping matrices. Vector of excitation forces.
System solutions, eigenvalues and eigenvectors. Natural frequencies and vibration modes.
Measuring reference. Static coupling and dynamic coupling
Modal analysis

T4-Condition control 1 (4 hours)

Dynamic response of a piece of equipment, in global values of signal amplitude over time - initial dynamic signature and its evolution, trend analysis.
Dynamic response of equipment in frequency amplitude.
Relationship between the geometric characteristics of equipment and typical frequencies.
Frequency ranges associated with equipment, warning, alert and alarm limits.
Dynamic response of equipment in terms of frequency range - initial dynamic signature and its evolution, trend analysis.
Applicability of vibration measurement in displacement, speed and acceleration.
Inspection plans and routines.

T5- Condition Control Systems 2 (4 hours)

Measurement chain for signal acquisition, principles.
Signal acquisition technology
Measurement parameters: Displacement, speed and acceleration
Displacement, speed and acceleration sensors
Maximum frequency, minimum frequency, line resolution, averages
Signal analysis equipment
Anti-alliasing features; hanning
Types of averages: linear, peak hold, exponential’
Standards with vibration amplitude limit values
Vibration values measured in displacement, velocity and acceleration, applicability.
Organisation and preparation of measurements. Inspection plans and routines.

T6- Monitoring (4 hours)

Monitoring and analysing data. Trend analysis.
Data processing and diagnosis.
Complementary analysis technologies.
Prognosis and support for predictive maintenance.
Data organisation, databases
Discrete and continuous monitoring.

P1- Condition control (4 hours)

Use of signal acquisition equipment

- Measuring parameters: Displacement, speed and acceleration
- Displacement, speed and acceleration sensors
- Maximum frequency, minimum frequency, line resolution, averages

Organisation and preparation of measurements
Dynamic characterisation of equipment
Dynamic signature

P2- Anomaly detection - forced regime response (4 hours)

Predicting the dynamic response of transmissions, turbomachinery, rolling and sliding bearings, etc.
Predicting the dynamic response of reciprocating machines, combustion engines.
Analysing the typical response of transmissions, turbomachinery, rolling and sliding bearings, etc.
Analysing the dynamic response associated with faults and operating irregularities, misalignment, imbalance, loosening, etc.
Case analyses

P3-Detection of response in free regime (4 hours)

Amplitude and phase measurements.
Experimental determination of natural frequencies. Methods
Impact tests to characterise natural frequencies.
Experimental determination of damping
Case analyses

P4-Equilibration and alignment (4 hours}

Fundamentals of balancing. Typical dynamic response, Modus operandi.
Balancing in 1 and 2 planes
Fundamentals of alignment. Typical dynamic response, Modus operandi.
Case analyses
Applicable standards

P5-Diagnosis and prognosis of dynamic behaviour (4 hours)

Equipment characterisation through vibration analysis
Characterisation of dynamic behaviour, diagnosis of developing faults
Prediction of the evolution of developing faults, prognosis.
Applicable standards