Jyoti Sinha

• PhD, CEng, FIMechE
• Managing Director at The University of Manchester

Purpose Effective asset management is grounded in a strategic framework prioritising assets according to their criticality to minimise downtime, reduce maintenance costs and maintain operational efficiency. This paper introduces a unified framework for asset ranking that integrates expert insights, criteria weighting and risk assessment techniques....

Bearings are pivotal components of rotating machines where any defects could propagate and trigger systematic failures. Once faults are detected, accurately predicting remaining useful life (RUL) is essential for optimizing predictive maintenance. Although data-driven methods demonstrate promising performance in direct RUL prediction, their robustn...

This study presents an efficient vibration-based fault detection method for rotating machines utilising the poly-coherent composite spectrum (pCCS) and machine learning techniques. pCCS combines vibration measurements from multiple bearing locations into a single spectrum, retaining amplitude and phase information while reducing background noise. T...

This paper proposes a methodological approach that can be applied in practice for evaluating stakeholder dynamics and assessing projects against appropriate value propositions within an industrial maintenance project context. A conceptual framework is proposed and is demonstrated through a case analysis. It is expected that the proposed methodology...

Multi-sensor monitoring is prevalent in modern structural health monitoring (SHM) practice. As the number of sensors and sampling requirements increase, a monitoring sensor network can generate substantial data which are high-volume and high-dimensional, especially for large structure and machinery. In condition-based monitoring (CBM) of rotating m...

A robust and reliable condition monitoring and fault diagnosis system is crucial for an efficient operation of industries. Because of the advances in technologies over the past few decades, there is an increased interest in developing intelligent systems to perform tasks that traditionally rely on knowledge, experience and expertise of an individua...

In any industry, it is the requirement to know whether the machine is healthy or not to operate machine further. If the machine is not healthy then what is the fault in the machine and then finally its location. The paper is proposing a 3-steps methodology for the machine fault diagnosis to meet the industrial requirements to aid the maintenance ac...

On top of the condition-based maintenance (CBM) practice for rotating machinery, the robust estimation of remaining useful life (RUL) for rolling-element bearings (REB) is of particular interest. The failure of a single bearing often results in secondary defects in the connected structure and catastrophic system failures. The prediction of RUL faci...

The 2-Steps Smart Rotor Fault Diagnosis Model (SRFDM) is proposed. This consists of a supervised classic pattern recognition artificial neural network (ANN), which uses parameters extracted from the measured vibration signals from the machine. The Step-1 identifies the machine is healthy or faulty, and then the classification of faults in the Step-...

Anti-friction bearings (AFB) are crucial structural components conveying rotating motions in a variety of mechanical systems. To avoid unscheduled breakdowns and fatal failures, remaining useful life (RUL) prediction is of great practical significance in industrial practice for prognostics health management, e.g., optimizing maintenance plan for co...

Earlier studies have optimised the vibration-based parameters to identify the rotor defects only for the rotating machines. The artificial neural network (ANN) model was used earlier to classify the faults. The earlier optimised parameters are further examined for both rotor and bearing defects. These parameters are slightly modified in this resear...

This paper analyses research developments in the dynamics of stakeholders and their impact mechanisms on the creation of value through a literature review. Three databases, Scopus, Science Direct and Google Scholar are selected to search articles. This study employs a quantitative descriptive analysis and a qualitative thematic analysis to provide...

This study builds upon previous research that utilised a vibration-based machine learning (VML) approach for diagnosing rotor-related faults in rotating machinery. The original method used artificial neural networks (ANN) to classify rotor-related faults based on optimised vibration parameters from the time and frequency domains. This study expands...

Anti-friction bearings (AFB) are essential parts of many rotating machines. It is also well known that the fault in the bearings keeps developing during machine operation. This bearing fault can propagate further and trigger other faults within the machine, and eventually lead to the machine failures and shutdown. Hence, the early prediction of rem...

Condition monitoring and fault diagnosis are topics of growing interest for improving the reliability of modern industrial systems. As critical structural components, anti-friction bearings often operate under harsh conditions and are contributing factors of system failures. Efforts have been cast on bearing diagnostics under the sensor fusion and...

In response to the competing factors governing the operation of oil and gas facilities, i.e., the stringent safety and environmental regulations, and the challenging business environment that entails minimizing the running cost, a risk-based inspection (RBI) program became a vital part of all Asset Integrity Management (AIM) frameworks. The objecti...

Acoustic Wave Reflection (AWR) approach seems to be the future avenue for long pipeline monitoring, typically for the oil and gas industries. There are several research studies are available on successful detection of defects using this AWR approach in the pipelines based on the laboratory scaled experiments. The method seems to be successfully app...

An intelligent fault diagnosis model of identical machines with different operating conditions has been developed earlier. The model is based on the experimental vibration data with several rotor related faults in the experimental rig and their faults diagnoses through artificial neural network (ANN). This method is further validated through the fi...

Purpose The purpose of this paper is to analyze the reliability of the quantitative risk model used for planning inspection and maintenance activities. The objective is to critically discuss the factors that contribute to the probability and consequence of failure calculations. Design/methodology/approach The case study conducted using one of the...

Mathematical models have been widely used in the study of rotating machines. Their application in dynamics has eased further research since they can avoid time-consuming and exorbitant experimental processes to simulate different faults. The earlier vibration-based machine-learning (VML) model for fault diagnosis in rotating machines was developed...

Plant availability and reliability can be improved through a robust condition monitoring and fault diagnosis model to predict the current status (healthy or faulty) of any machines and critical assets. The model can then predict the exact fault for the faulty asset so that remedial maintenance can be carried out in a planned plant outage. Nowadays,...

This paper gives a practical systematic approach towards the maintenance procedure optimisation of a critical industrial unit in operation, to improve its maintainability. The resolution of the maintainability challenge in the industrial unit (Vibrating screen unit - VSU) was realised by performing a two-phase critical analysis, encompassing critic...

In this paper, we propose a novel hybrid adaptive model (HAM) that integrates Gaussian mixture probabilistic machine learning (ML), Weibull time-to-failure feature, and value of information (VOI) techniques for complex engineering failure analysis. The objective is to establish an optimum components replacement intervention strategy for composite b...

Earlier, a Machine Learning (ML) model has been developed for the rotating machine fault diagnosis using the experimental vibration data from a rig at two different rotating speeds. The ML model is showing good adaptability at 2 different speeds. In this paper, a finite element (FE) model for the rig is developed to understand the dynamics and to v...

Rolling stock (RS) service reliability is a key performance indicator for any railway operator and customer satisfaction. Failures to complete scheduled services by trains due to inherent system failures incur penalty charges. Therefore, a reliability improvement as a continuous improvement strategy is an essential initiative to ensure that the req...

Railway transport system (RTS) failures exert enormous strain on end-users and operators owing to in-service reliability failure. Despite the extensive research on improving the reliability of RTS, such as signalling, tracks, and infrastructure, few attempts have been made to develop an effective optimisation model for improving the reliability, an...

This volume gathers the latest advances, innovations and applications in the field of condition monitoring, plant maintenance and reliability, as presented by leading international researchers and engineers at the 5th International Conference on Maintenance Engineering and the 2020 Annual Conference of the Centre for Efficiency and Performance Engi...

Chemical, petrochemical, and refinery sectors have been facing tougher safety, environmental and mechanical integrity regulations as well as challenges associated with the need for cost reduction to improve competitiveness. Risk‐based Inspection (RBI) is a cost‐effective approach to manage operational risks by making an informed decision on inspect...

Artificial intelligence (AI)-based machine learning (ML) models seem to be the future for most of the applications. Recent research effort has also been made on the application of these AI and ML methods in the vibration-based faults diagnosis (VFD) in rotating machines. Several research studies have been published over the last decade on this topi...

Purpose The development and application of intelligent models to perform vibration-based condition monitoring in industry seems to be receiving attention in recent years. A number of such research studies using the artificial intelligence, machine learning, pattern recognition, etc., are available in the literature on this topic. These studies esse...

Analysis and investigation of the applicability of Maintenance Assessment/Audit methodology used in a Manufacturing firm was done based on previous maintenance experience on an Oilfield Production Asset (Floating, Production, Storage and Offloading Asset – FPSO). The Audit/Assessement Methodology used in PepsiCo International was reported in detail...

Earlier studies have successfully demonstrated the use of the poly-coherent composite bispectrum (pCCB) in the faults identification in rotating machines. However, only amplitudes of the pCCB components were used in the earlier studies. Since the pCCB components are complex numbers (both amplitudes and phases). Hence, the real and imaginary feature...

This paper presents a methodology for the mechanical characterization of agarose millimetric spheres using resonant principles. Detection of the modes of vibration was conducted using a low-cost experimental setup based on an electret microphone adapted with a thin latex elastic membrane for the sensing stage and a piezoelectric actuator driven by...

The purpose of this study is to propose a novel hybrid dynamic probability-based failure analysis technique consisting of dynamic Bayesian discretization (DBD) and stochastic Petri nets (SPNs) for railway rolling stock (RS) failure analysis. Performing failure analysis and diagnoses for integrated RS subsystems is challenging and can lead to operat...

There have been a number of significant power outages caused by unexpected levels of flow-induced vibration of valves in partially-open operating conditions and as such the understanding of this phenomena is critically important. On-site testing is normally expensive and inherently difficult given typical flow rates but while computational fluid dy...

The earlier model-based rotor mass unbalance estimation methods have used two orthogonal sensors per bearing pedestal. It is generally believed that the vibration measurement at two orthogonal directions provides the bigger picture of machine dynamical behaviour. However, in the present study, the concept of the earlier method is applied again but...

The poly-coherent composite higher order spectra (pCCHOS) were used earlier for faults diagnosis in the rotating machine. Earlier research studies have also suggested the unified multi-speeds approach for identical machines but with different operating speeds. However the studies were only tested at several machine speeds but below the first critic...

Purpose Generating electricity from wind turbines is currently a viable option to meet the electric power requirements in many countries. The structure of offshore wind turbines is constantly subjected to external dynamic loads due to wind, waves and rotor loads due to the rotation of blades. The frequency content of these dynamic loads is in the r...

The quantified approach for health monitoring of subsea pipelines has been proposed, it considers four key time based degradation parameters selected from an array of mechanisms due to its ramification in deterioration and ageing of pipeline assets in general. The inspection data obtained for the selected parameters are simulated in a proposed heal...

Earlier research studies have suggested the unified vibration-based approach for fault diagnosis (FD) in identical machines with different foundation flexibilities and multi-rotating speeds. Intially the acceleration-based features were used for this approach then further work optimised the approach by combining acceleration and velocity features f...

The development of technologies for the maintenance industry has taken an important role to meet the demanding challenges. One of the important challenges is to predict the defects, if any, in machines as early as possible to manage the machines downtime. The vibration-based condition monitoring (VCM) is well-known for this purpose but requires the...

The paper reports the computational fluid dynamics (CFD) investigations of the flow induced excitations in a high-pressure integral throttle valve. The effect of the valve openings on the characteristics of the unsteady fluids force on the valve head are studies. 2D CFD models are developed based on high pressure integral throttle valve and normal...

Purpose The purpose of this paper is mainly to highlight how a simplified and streamlined approach to the condition monitoring of industrial rotating machines through the application of frequency domain data combination can effectively enhance the eMaintenance framework. Design/methodology/approach The paper commences by providing an overview to...

The most common cause of the excessive vibration in rotating machines is the rotor mass unbalance. If a machine vibration due to mass unbalance exceeds the alarm limits, then it may lead to machine failure. Therefore, rotating machines should be regularly checked to ensure that they are properly balanced. Currently, industries use the influence coe...

Rotor unbalance is one of the common faults in any rotating machine which occurs regularly during their operation. This may cause unacceptable level of vibration leading to failure of the machine. Hence the regular field balancing is generally carried out to keep the machine vibration within acceptable limit. The influence coefficient (IC) method i...

The rotor mass unbalance is probably the most common rotor fault in any rotating machine. If the rotor mass unbalance exceeds the allowable limit, it will cause an excessive vibration which may lead to machine failure. Therefore, the regular in-situ rotor balancing is often required to keep machine vibration within acceptable level. Current practic...

The paper investigates effects of various valve openings on the unsteady fluids forces on the stem of a high-pressure governor valve through a simple simulated CFD (Computational Fluid Mechanics) study. A validated CFD model is developed based on the earlier experimental study on a simple mechanical valve published in the literature. The CFD model...

Rotor mass unbalance is almost unavoidable fault in the existing rotating machines. Therefore, it is important to keep the unbalance related synchronous vibrations in satisfactory level during machine operation. The influence coefficient (IC) balancing approach is commonly used in industries for balancing of rotating machines. The method is current...

In an earlier study, the poly-coherent composite higher order spectra (i.e. poly-coherent composite bispectrum and trispectrum) frequency domain data fusion technique was proposed to detect different rotor-related faults. All earlier vibration-based faults detection involving the application of poly-coherent composite bispectrum and trispectrum hav...

DOI:http://dx.doi.org/10.1103/PhysRevB.93.219902

Through an earlier experimental study, an integrated fault classification approach was suggested for machines operating at different speeds. The suggested method was observed to separate faults adequately, which can lead to fault diagnosis. However, theoretical understanding of the proposed methods is important to further enhance the confidence of...

The steam turbo-generator (TG) sets in power plants during the shutdown period often operate at a very low speed with the aid of barring gear. This low speed is known as the barring speed and it is of the order upto 100RPM. The purpose is to float the rotor in the fluid bearings so that the rotor heavy self-weight should not cause any damage to the...

Cracking of a few last stage blades of the Low Pressure (LP) turbines is observed in a typical steam Turbo-Generator (TG) unit at the West Burton Power Plant UK. In-situ vibration measurements are carried out during the steady state operation at different power generation outputs. A typical phenomenon of appearance of low frequencies in band of 7-1...

The evolution of damping in Co/Pt, Co/Au, and Ni81Fe19/Pt bilayers was studied with increasing nonmagnetic (NM) heavy-metal layer thicknesses in the range 0.2nm≤tNM≤10nm, where tNM is the NM layer thickness. Magnetization precession was measured in the time domain using time-resolved magneto-optical Kerr effect magnetometry. Fitting of the data wit...

Literatures have shown that there is a significant rise in the use of measured vibro-acoustic signals for faults diagnosis in rotating machines. This is particularly based on the premise that affluent information about a rotating machine’s operating conditions is usually conveyed by the sounds of the machine. Several earlier studies have already sh...

Interface modification for control of ultrafast magnetic properties using low-dose focused ion beam irradiation is demonstrated for bilayers of two technologically important materials: Ni81Fe19 and Pt. Magnetization dynamics were studied using an all-optical time-resolved magneto-optical Kerr microscopy method. Magnetization relaxation, precession,...

Equipment standardisation as a cost-effective means of rationalising maintenance spares has significantly increased the existence of several identical (similar components and configurations) ‘as installed’ machines in most industrial sites. However, the dynamic behaviours of such identical machines usually differ due to variations in their foundati...

Earlier proposed methods in the literature on the rotor unbalance and foundation model estimation using a single machine rundown data have used vibration measurements at all bearing pedestals in both lateral and vertical orthogonal directions. It is generally believed that the measurement in both directions provides the bigger picture of machine dy...

Conventional Vibration-based Condition Monitoring (VCM) is well known and well accepted in industries to identify the fault(s), if any, in rotating machine since decades. However over the last 3 decades, significant advancement in both computational and instrumentation technologies has been noticed which resulted in number of research studies to fi...

Composite spectrum and composite bispectrum techniques have been recently developed for identifying fault(s) in rotating machines. The fusion of the measured vibration data at all the machine bearings in the frequency domain is used to construct such a composite spectrum and composite bispectrum for the representation of the entire machine. These t...

An experimental study on the shaft orbit response for different rotor related faults is presented in this paper. Similar previous studies in readily available literature were done considering a few fault conditions on different machines. Therefore, an opportunity exists to provide further insight to changes in the behaviour of a single machine when...

A class of signal processing tools, Higher Order Spectra (HOS) and their normalised amplitudes Higher Order Coherences (HOC) have been receiving attentions in numerous applications, including Health Monitoring (HM) techniques for structures and machines. It is however difficult to decide which of the tools (HOS or HOC) gives the best diagnostic fea...

A simplified summary of in-house developed user friendly multi-channel data collection and signal processing capabilities for the vibration-based condition monitoring of plant assets in a cheaper manner is presented here.

Satisfactory operation of any machine is always important for plant safety, increased productivity, and low downtime and maintenance overhead. Such requirements could usually be fulfilled by proper design and installation of machines at site. Design part is perhaps more matured in most cases, however installation may play a significant role in the...

It is commonly observed in practise that rotating machines installed at different plant locations often exhibit different dynamic behaviours, due to variations in the flexibilities of their supports. This often makes the faults diagnosis complex from one machine to another machine. In the current study, a similar scenario has been experimentally si...

A better understanding of the characteristic features of different faults associated with rotating machines is very vital, so that appropriate and timely maintenance interventions can be recommended prior to the occurrence of catastrophic failures. Rotor orbit analysis of machine vibration data collected using proximity probes has been observed to...

For rotating machinery in which speeds and dynamics constantly change, performing vibration-based condition monitoring can be challenging. Thus, an effort is made here to develop a Unified Multi-speed fault diagnosis technique that can exploit useful vibration information available at various speeds from a rotating machine in a single analysis. Com...

Despite numerous difficulties that can be encountered when using trend monitoring of harmonic components from the simple amplitude spectra to aid diagnosis of rotor related faults on large multi-stage multi-bearing rotating machines, the technique continues to be the mainstay in industry. This is due in part to factors including a lack of adequate...

Measured vibration responses can be processed either in their original time domain or after converting to the frequency domain for the purpose of damage detection. Recently, two new vibration-based methods have been presented separately which successfully identified the location of damage in beam-like structures. One of the methods utilises the vib...

Envelope analysis of vibration signals is a well known tool for amplitude demodulation and diagnosis of a number of vibration problems in machines and structures. The typical application is the fault diagnosis in the anti-friction bearings and gearboxes. Hilbert transformation (HT) is often used to extract the envelope signals (upper and lower) fro...

This paper intends to extend the application of the residual operational deflection shape (R-ODS) to a simplified model of the LP turbine of a steam turbo generator. The numerical model consists of a stepped shaft which accommodates some balance disks to represent the blades at different stages of the LP turbine. The ability of the R-ODS method in...

Earlier studies have shown the possibilities of detecting different faults on a rigidly supported rotating machine through coherent composite spectrum (CCS) and coherent composite bispectrum (CCB) data fusion techniques. The current paper is also related to the use of CS, CB and a newly introduced coherent composite trispectrum (CCT) for faults ide...

In a previous study, a combined vibration and temperature analysis technique for the diagnosis of commonly encountered rotor related faults produced good practicable results even without the use of temperature. This was, however, developed on an experimental rig with relatively rigid supports. The objective of the current study is to investigate th...

Rotating blades are considered as the most common cause of failures in rotating machinery. In the present research study, the dynamics of the blades both in the healthy and crack conditions are studies on a small experimental rig using the on-bearing and on-casing vibration, which are measured using the accelerometer on bearing pedestals and on cas...

In situ vibration measurements are carried out on a a typical steam turbo-generator (TG) unit at the West Burton Power Plant UK during the steady state operation. A typical phenomenon of appearance of low frequencies in band of 7–12 Hz is observed mainly related to the vibration measurements on low pressure (LP) turbines bearing pedestals. This ban...

The VETOMAC-X Conference covered a holistic plethora of relevant topics in vibration and engineering technology including condition monitoring, machinery and structural dynamics, rotor dynamics, experimental techniques, finite element model updating, industrial case studies, vibration control and energy harvesting, and signal processing. These proc...

Provides Typical Abstract Representations of Different Steps for Analyzing Any Dynamic System Vibration and dynamics are common in everyday life, and the use of vibration measurements, tests, and analyses is becoming standard for various applications. Vibration Analysis, Instruments, and Signal Processing focuses on the basic understanding of vibra...

The composite spectrum (CS) data fusion technique has been shown to simplify rotating machines faults diagnosis by earlier studies. Faults diagnosis with the earlier CS relied solely on the amplitudes of several harmonics of the machine speed, owing to the loss of phase information leading to its computation. The proposed improved CS applies the co...

Rotating blades are considered as the most common cause of failures in rotating machinery. In the present research study, the dynamics of the blades both in the healthy and cracked conditions are studied on a small experimental rig using the on-bearing vibration and shaft torsional vibration which are measured using the accelerometer and the increm...

Conventional vibration-based condition monitoring (VCM) of rotating machines with a multiple bearing system, such as Turbo-generator (TG) sets, is data intensive. Since a number of sensors are required at each bearing location, the task of diagnosing faults on such systems may be impossible for even an experi-enced analyst. Hence, the current study...

Detection of fatigue cracks at an early stage of their development is important in structural health monitoring. The breathing of cracks in a structure generates higher harmonic components of the exciting frequency in the frequency spectrum. Previously, the residual operational deflection shape (R-ODS) method was successfully applied to beams with...

The effect of spin torque from the spin Hall effect in Pt/Ni81Fe19 rectangular bilayer film was investigated using time-resolved magneto-optical Kerr microscopy. Current flow through the stack resulted in a linear variation of effective damping up to +_7%, attributed to spin current injection from the Pt into the Ni81Fe19. The spin Hall angle of Pt...

Cracks are one of the common defects in structural components that may ultimately lead to failure of structures if not detected. Generally, most of the vibration based crack detection methods transform measured vibration responses from time-domain into frequency-domain using Fourier or wavelet transform for damage detection. However, it would be mo...

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