This session provides a comprehensive introduction to fatigue crack growth, combining theory, practical analysis methods, and hands-on testing techniques. It covers how repeated loading leads to crack initiation and growth, and the key design strategies, such as Infinite Life, Safe Life, Fail-Safe, and Damage Tolerance, used to prevent structural failure.
Attendees will gain practical insight into fracture mechanics, including crack growth laws, R-ratio effects, retardation models, and calculation techniques, bridging the gap between theory and real-world application. The session also highlights fatigue crack growth testing at HBK’s Advanced Materials Characterisation & Testing (AMCT) facility, showcasing specimen geometries, measurement methods, and case studies that demonstrate how testing informs reliable design and engineering decisions.
Fatigue is the most common cause of structural failure when components are subjected to repeated (cyclic) loading. Fatigue failure usually occurs in two stages:
The time spent in each stage depends on factors such as the material used, the design of the structure, and how it is loaded in service. In some cases, a crack may grow into a low-stress area and stop progressing. If the crack does not affect the component’s performance or safety, it may be considered acceptable during service.
This presentation introduces the main design strategies used to prevent failure during service, along with the calculation methods that support them:
These methods rely on material properties obtained through testing and statistical analysis. Because fatigue and fracture predictions are highly sensitive to these input values, today’s programme will explore how fracture mechanics can be applied to real-world component design.
Head of Materials Testing, HBK
Michelle holds a Master’s degree in Aeronautical Engineering and a PhD studying the damage resistance and tolerance of composite sandwich structures, obtained from Loughborough University. She joined HBK in May 2017, having previously held the position of Chief of Materials at the Rolls-Royce CTAL facility on the Isle of Wight. Her speciality is in composite materials characterisation and testing, with hands-on experience in defining and executing large material qualification programmes.
Having spent 10 years on the Rolls-Royce composite fan system programme, leading the Materials team, Michelle has experience of how to relate materials testing to real applications and how to characterize difficult structures such as hybrid joints. At HBK she is responsible for the AMCT facility and the management of the commercial testing activities along with research into the fatigue behaviour of additively manufactured materials and composites.
Fracture Mechanics has been a key area of study since the 1950s. Over the decades, many foundational methods, references, and standards have been developed—many of which are still widely used today. At the same time, newer approaches have emerged, offering improved accuracy and broader applicability. This rich and evolving history can make it challenging for new engineers to grasp the subject.
This presentation provides a practical overview of the most commonly used Fracture Mechanics methods, aimed at young engineers and their mentors.
We begin by comparing typical use cases for Fracture Mechanics versus Fatigue analysis. The talk then introduces key concepts such as crack growth laws and R-ratio effects, with reference to models by Paris, Forman, Walker, Austen, NASGRO 3, and piecewise linear interpolation.
Next, we explore the non-linear effects of load sequence, focusing on retardation models including Wheeler’s approach and various adaptations of the Willenborg model.
Finally, we present two widely used calculation techniques:
The presentation concludes with a brief look at more modern Fracture Mechanics models, with particular emphasis on the Total-Life approach, which will be covered in more detail in a later presentation.
Director of Technology - nCode Products, HBK
Dr. Halfpenny has a PhD in Mechanical Engineering from University College London (UCL) and a Master’s in Civil and Structural Engineering. With over 25 years of experience in structural dynamics, vibration, fatigue and fracture, he has introduced many new technologies to the industry including: FE-based vibration fatigue analysis, crack growth simulation and accelerated vibration testing. He holds a European patent for the ‘Damage monitoring tag’ and developed the new vibration standard used for qualifying UK military helicopters.
He has worked in consultancy with customers across the UK, Europe, Americas and the Far East, and has written publications on Fatigue, Digital Signal Processing and Structural Health Monitoring. He sits on the NAFEMS committee for Dynamic Testing and is a guest lecturer on structural dynamics with The University of Sheffield.
This presentation offers a detailed overview of fatigue crack growth testing techniques. It covers key specimen geometries, including Compact Tension (CT) and Single Edge Notched Bending (SENB), with practical guidance on technical challenges and criteria for selecting the appropriate configuration.
Methods for measuring crack length are compared, including camera-based systems, Crack Opening Displacement (COD) gauges, the potential drop (PD) technique, and HBK’s RDS series crack propagation strain gauges—with a focus on accuracy and resolution.
We examine the influence of crack tip plasticity and the complexities introduced by load shedding and retardation effects. Particular attention is given to compression–compression pre-cracking as an effective method for reducing retardation artefacts.
The importance of testing across a range of R-ratios and applying mean stress corrections is discussed to ensure realistic modelling of material behaviour under service conditions.
The Advanced Materials Characterisation and Testing (AMCT) facility at HBK combines servo-hydraulic test rigs with high-speed data acquisition systems, enabling high-fidelity measurements and reliable results. Automated analysis tools support efficient reporting and ensure full traceability.
The presentation concludes with a case study demonstrating the application of these methods in an aerospace context, highlighting their practical benefits and implementation.
Materials Engineer - Fatigue and Fracture, HBK
Alex holds a PhD in Aerospace Materials and has previously served as a Research Fellow in Metallic Materials at the University of Birmingham, where he contributed to multiple UKRI-funded Rolls-Royce programmes as well as collaborative projects with Eurotunnel and Baowu Steel. His research included developing an innovative fracture and fatigue testing procedure with in-situ non-destructive monitoring techniques for aerospace titanium welds, failure analysis in railway suspension springs; and evaluating the cryogenic fracture behaviour of steels for nuclear power plant applications. He has authored multiple technical reports and conference papers, consistently delivering industry-focused solutions.
Alex joined HBK in May 2025. With over six years of experience in fatigue and fracture testing, failure investigation, and materials characterisation, he is contributing to the team by developing a novel fatigue crack growth testing method, while enhancing analysis capabilities and the quality of project deliverables.
This session focuses on understanding and quantifying fatigue crack growth to enable more accurate life predictions and robust component design. It covers how material parameters can be derived from high-fidelity test data at HBK’s Advanced Materials Characterisation & Testing (AMCT) facility, ensuring that crack growth models reflect real-world behaviour.
Attendees will learn about delta K threshold, the stress intensity range below which cracks do not propagate, and how Compression-Precracking Constant Amplitude (CPCA) provides a reliable testing approach to determine accurate and conservative estimates of delta K threshold.
The session concludes by introducing the Total-Life method, implemented as WholeLife in nCode DesignLife. This unites strain-life and fracture mechanics principles to predict fatigue life across both crack initiation and crack growth stages. It incorporates a state-of-the-art multiaxial crack-tip plasticity model to account for mean stress effects and overload-induced retardation.
Senior Technologist of Fatigue and Fracture, HBK
Dr. Cristian Bagni holds a PhD in Structural Engineering (The University of Sheffield, UK) and a Master’s Degree in Civil and Structural Engineering (Unversità degli Studi di Parma, Italy).
After working for several years at the University of Sheffield’s Advanced Manufacturing Research Centre (AMRC) on high profile aerospace research projects, he also gained extensive experience on advanced manufacturing processes.
Cristian is currently Senior Technologist for Fatigue and Fracture at Hottinger Brüel & Kjær, and amongst his activities he leads and he is involved in several research topics including fatigue behaviour of joints, composites, additively manufactured materials and fatigue crack growth. He also supports HBK’s Advanced Materials Characterisation & Testing (AMCT) facility with the analysis and post-processing of fatigue test results, and consequent characterisation of both joints and parent materials.
He has co-authored several papers on Computational Mechanics and Fatigue, and has acted as reviewer for various International Journals.
Just as the Fatigue Strength threshold defines a stress level below which fatigue failure is unlikely, fracture mechanics introduces the delta K threshold - the stress intensity range below which a crack will not grow significantly. Stress intensity depends on crack length, applied stress range, and geometry factor.
For components that are difficult or impossible to inspect during service, it is common practice to design them so that operational stress cycles remain well below the stress range value associated with an assumed intrinsic flaw size. These flaws may arise from manufacturing defects such as porosity or inclusions. Non-destructive testing is typically used to ensure that any flaws are smaller than the critical threshold.
However, accurately determining delta K threshold is a complex task. Traditional standards have often relied on the K-decreasing method, which has been shown to produce non-conservative estimates due to residual stress effects and crack closure (retardation). This presentation introduces a more reliable approach developed by Prof. J. Newman: the Compression-Precracking Constant Amplitude (CPCA) method, which provides more accurate and conservative estimates of delta K threshold.
We will review how delta K threshold is defined in various international standards, examine the limitations of the historical K-decreasing method, and explain how residual stresses can lead to misleading results. The session concludes with a detailed explanation of the CPCA test method and its analysis process.
Director of Technology – nCode Products, HBK
Dr. Halfpenny has a PhD in Mechanical Engineering from University College London (UCL) and a Master’s in Civil and Structural Engineering. With over 25 years of experience in structural dynamics, vibration, fatigue and fracture, he has introduced many new technologies to the industry including: FE-based vibration fatigue analysis, crack growth simulation and accelerated vibration testing. He holds a European patent for the ‘Damage monitoring tag’ and developed the new vibration standard used for qualifying UK military helicopters.
He has worked in consultancy with customers across the UK, Europe, Americas and the Far East, and has written publications on Fatigue, Digital Signal Processing and Structural Health Monitoring. He sits on the NAFEMS committee for Dynamic Testing and is a guest lecturer on structural dynamics with The University of Sheffield.
Materials Engineer - Fatigue and Fracture, HBK
Alex holds a PhD in Aerospace Materials and has previously served as a Research Fellow in Metallic Materials at the University of Birmingham, where he contributed to multiple UKRI-funded Rolls-Royce programmes as well as collaborative projects with Eurotunnel and Baowu Steel. His research included developing an innovative fracture and fatigue testing procedure with in-situ non-destructive monitoring techniques for aerospace titanium welds, failure analysis in railway suspension springs; and evaluating the cryogenic fracture behaviour of steels for nuclear power plant applications. He has authored multiple technical reports and conference papers, consistently delivering industry-focused solutions.
Alex joined HBK in May 2025. With over six years of experience in fatigue and fracture testing, failure investigation, and materials characterisation, he is contributing to the team by developing a novel fatigue crack growth testing method, while enhancing analysis capabilities and the quality of project deliverables.
Fatigue failure typically occurs in two stages: crack initiation (or nucleation) and crack growth (or propagation). The relative importance of each stage depends on factors such as the material, structural design, and application.
Traditionally, these stages are analysed using separate models:
Strain-life (E–N) methods for crack initiation
Linear Elastic Fracture Mechanics (LEFM) or Elastic–Plastic Fracture Mechanics (EPFM) for crack growth
Most simulation tools focus on one stage or the other, which can lead to inaccurate fatigue life predictions—especially in modern lightweight structures such as welded assemblies, jointed components, and cast parts, where both stages are significant.
This presentation introduces the Total-Life method, a unified approach that combines strain-life and fracture mechanics principles to estimate fatigue life across both stages. It incorporates a state-of-the-art multiaxial crack-tip plasticity model to account for mean stress effects and overload-induced retardation.
We will explore the advantages of the Total-Life method over traditional approaches and demonstrate its potential through a real-world case study.
Senior Technologist of Fatigue and Fracture, HBK
Dr. Cristian Bagni holds a PhD in Structural Engineering (The University of Sheffield, UK) and a Master’s Degree in Civil and Structural Engineering (Unversità degli Studi di Parma, Italy).
After working for several years at the University of Sheffield’s Advanced Manufacturing Research Centre (AMRC) on high profile aerospace research projects, he also gained extensive experience on advanced manufacturing processes.
Cristian is currently Senior Technologist for Fatigue and Fracture at Hottinger Brüel & Kjær, and amongst his activities he leads and he is involved in several research topics including fatigue behaviour of joints, composites, additively manufactured materials and fatigue crack growth. He also supports HBK’s Advanced Materials Characterisation & Testing (AMCT) facility with the analysis and post-processing of fatigue test results, and consequent characterisation of both joints and parent materials.
He has co-authored several papers on Computational Mechanics and Fatigue, and has acted as reviewer for various International Journals.
This session explores the effects of elevated temperatures on material fatigue performance, providing practical guidance for analysis, testing, and life prediction in demanding environments. It covers isothermal and thermomechanical fatigue, including how temperature influences microstructural behaviour, creep, oxidation, and their interactions with cyclic loading.
Attendees will gain insights into testing methods and modelling approaches, from traditional isothermal techniques to the advanced Chaboche method, highlighting ways to improve efficiency, reduce costs, and maintain accuracy.
The session will demonstrate how nCode DesignLife and nCode GlyphWorks can incorporate temperature effects and creep rupture analysis into fatigue workflows, enabling realistic, reliable predictions for components operating under high-temperature conditions.
The fatigue performance of materials often deteriorates significantly at elevated temperatures. This presentation begins with a discussion of how temperature affects the microstructural behaviour of materials, focusing on the mechanisms of fatigue, creep, oxidation, and their interactions.
Finite Element (FE) stress analysis must also account for thermal effects. We explore the application of elastic, elastic–plastic, and elastic–viscoplastic models in this context.
Fatigue behaviour at high temperatures depends on how temperature and stress vary over time. Load conditions are typically classified into two categories:
The presentation outlines suitable analysis methods and materials testing requirements for each category. It introduces the Chaboche model, which can be applied to both loading types and helps reduce the cost of materials testing.
We also examine creep rupture and its compounded interaction with fatigue failure, introducing the Larson–Miller and Chaboche creep rupture models.
The session concludes with a review of laboratory tests on several materials at elevated temperatures under combined creep and fatigue conditions, illustrated through two case studies: a turbocharger housing and an exhaust gas recirculation (EGR) valve housing.
Director of Technology – nCode Products, HBK
Dr. Halfpenny has a PhD in Mechanical Engineering from University College London (UCL) and a Master’s in Civil and Structural Engineering. With over 25 years of experience in structural dynamics, vibration, fatigue and fracture, he has introduced many new technologies to the industry including: FE-based vibration fatigue analysis, crack growth simulation and accelerated vibration testing. He holds a European patent for the ‘Damage monitoring tag’ and developed the new vibration standard used for qualifying UK military helicopters.
He has worked in consultancy with customers across the UK, Europe, Americas and the Far East, and has written publications on Fatigue, Digital Signal Processing and Structural Health Monitoring. He sits on the NAFEMS committee for Dynamic Testing and is a guest lecturer on structural dynamics with The University of Sheffield.
Head of Materials Testing, HBK
Michelle holds a Master’s degree in Aeronautical Engineering and a PhD studying the damage resistance and tolerance of composite sandwich structures, obtained from Loughborough University. She joined HBK in May 2017, having previously held the position of Chief of Materials at the Rolls-Royce CTAL facility on the Isle of Wight. Her speciality is in composite materials characterisation and testing, with hands-on experience in defining and executing large material qualification programmes.
Having spent 10 years on the Rolls-Royce composite fan system programme, leading the Materials team, Michelle has experience of how to relate materials testing to real applications and how to characterize difficult structures such as hybrid joints. At HBK she is responsible for the AMCT facility and the management of the commercial testing activities along with research into the fatigue behaviour of additively manufactured materials and composites.
For materials operating in high-temperature environments, it is essential to account for the effects of temperature on fatigue performance. nCode DesignLife offers several methods to incorporate temperature effects into fatigue analysis using results from finite element stress and thermal simulations.
Recent developments in 2025 have introduced key enhancements in this area, including:
These advancements support more realistic and efficient fatigue analysis workflows, helping engineers better assess material performance in high-temperature applications.
Product Manager – nCode Desktop Products, HBK
Paul Roberts has been involved with fatigue and durability analysis for the over 40 years. He has been with HBK (formerly nCode) for a total of 19 years as an application engineer and product manager for the DesignLife product and more recently for all the nCode desktop products. Prior to joining nCode, Paul held positions in product development, testing, RLD analysis and FE based engineering consultancy at GKN Technology and Ricardo. Paul graduated with a degree in mechanical engineering from Aston University in Birmingham, UK.
While fatigue is typically associated with failure under varying loads, creep rupture refers to failure under sustained static loads. In the first presentation of the day, we introduced the physics of creep and its compounded interaction with fatigue.
nCode DesignLife and nCode GlyphWorks offer two approaches for analysing creep rupture—using results from finite element simulations and physical tests, respectively. This presentation provides a brief overview of the Larson–Miller and Chaboche creep rupture models and outlines the testing procedures required to derive the necessary material parameters.
These methods enable engineers to assess long-term durability in high-temperature environments, supporting more accurate life predictions for components exposed to static thermal loads.
Senior Technologist of Fatigue and Fracture, HBK
Dr. Cristian Bagni holds a PhD in Structural Engineering (The University of Sheffield, UK) and a Master’s Degree in Civil and Structural Engineering (Unversità degli Studi di Parma, Italy).
After working for several years at the University of Sheffield’s Advanced Manufacturing Research Centre (AMRC) on high profile aerospace research projects, he also gained extensive experience on advanced manufacturing processes.
Cristian is currently Senior Technologist for Fatigue and Fracture at Hottinger Brüel & Kjær, and amongst his activities he leads and he is involved in several research topics including fatigue behaviour of joints, composites, additively manufactured materials and fatigue crack growth. He also supports HBK’s Advanced Materials Characterisation & Testing (AMCT) facility with the analysis and post-processing of fatigue test results, and consequent characterisation of both joints and parent materials.
He has co-authored several papers on Computational Mechanics and Fatigue, and has acted as reviewer for various International Journals.
This session examines how reliability engineering is evolving to meet the demands of next-generation technologies, combining modern modelling approaches with practical testing strategies. It explores fresh perspectives on reliability across the design and operation space, capturing real world stress from data lakes, using smart testing, alongside new methods that extend Failure Mode and Effect Analysis (FMEA) to capture broader stakeholder voices and ensure complete test coverage.
Attendees will learn how smart testing can accelerate product qualification, by combining physical and virtual testing. The vibration qualification of an electric vehicle (EV) battery system is used as a case study to demonstrate this, from defining a suitable vibration profile, through integrated testing, to applying System-of-Systems reliability simulation across multiple failure modes for overall reliability.
Finally, the session addresses the importance of durability shaker testing - not only for evaluating product reliability but also for preserving shaker performance through best practices in operation, care, and maintenance.
Director of Technology – nCode Products, HBK
Dr. Halfpenny has a PhD in Mechanical Engineering from University College London (UCL) and a Master’s in Civil and Structural Engineering. With over 25 years of experience in structural dynamics, vibration, fatigue and fracture, he has introduced many new technologies to the industry including: FE-based vibration fatigue analysis, crack growth simulation and accelerated vibration testing. He holds a European patent for the ‘Damage monitoring tag’ and developed the new vibration standard used for qualifying UK military helicopters.
He has worked in consultancy with customers across the UK, Europe, Americas and the Far East, and has written publications on Fatigue, Digital Signal Processing and Structural Health Monitoring. He sits on the NAFEMS committee for Dynamic Testing and is a guest lecturer on structural dynamics with The University of Sheffield.
The Open University has recently developed a prototype design management tool that builds on the principles of Failure Mode and Effect Analysis (FMEA) to capture previously overlooked perspectives and ensure that all product requirements are addressed through a comprehensive qualification test matrix.
Traditional FMEA primarily reflects the Voice of the Engineer (VoE), focusing on mitigating reliability risks arising from potential failure modes. However, modern design and reliability management must also consider the Voice of the Customer (VoC), Voice of the Business (VoB), and Voice of the Regulator (VoR). Research at the Open University has introduced an analogous framework to FMEA that incorporates these additional voices, along with a new prioritisation metric—similar to APN (Action Priority Number) and RPN (Risk Priority Number)—to ensure these perspectives are not overlooked in the design process.
Furthermore, conventional FMEA lacks a method for formulating and tracking the effectiveness of qualification tests linked to each function or failure mode. Ideally, each function should be validated through a corresponding qualification test as part of the design verification and validation process. The new tool introduces a test matrix that maps functions to qualification tests, helping ensure complete test coverage.
Access to the prototype tool is available through the Open University, and lessons learned from its development will be shared to help evolve FMEA into a more inclusive and effective process for tomorrow’s engineering challenges.
Lecturer in Operations and Supply Chain Management, The Open University, UK
Dr Khadija Tahera is an academic at The Open University with over 15 years’ experience in engineering design, product development, and testing processes. Her research specialises in integrating physical and virtual testing to optimise strategies that facilitate the digitalisation of sustainable product design, thereby enhancing system reliability and accelerating innovation.
Dr Tahera has collaborated extensively with industry, providing practical methods and tools for verification, validation, and testing (VVT) in product development. She has led ESRC-funded projects and is currently leading an Innovate UK project to help Manufacturing SMEs improve testing strategies and VVT planning in the development of complex products. She is an elected member of the EPSRC Early Career Forum in Manufacturing and Circular Economy.
Currently, she teaches Operations and Supply Chain Management at The Open University Business School. Dr Tahera previously taught Manufacturing, Production and Project Management for six years as a senior lecturer at the University of Huddersfield. She also worked as a researcher at Cranfield University and as a consultant at the University of the Arts London.
She holds a PhD in "The Role of Testing in Engineering Design Processes" from The Open University (2014), two MSc degrees in Astronautics and Space Engineering from Cranfield University and Luleå University of Technology, Sweden, and a BSc in Computer Engineering.
As industries develop innovative technologies for a carbon-neutral future, ensuring reliability becomes increasingly challenging—especially when traditional qualification tests, based on extensive production experience, are not available. This presentation explores the benefits of combining physical and virtual testing to qualify the fatigue life of components.
Using the vibration qualification of an electric vehicle (EV) battery system as a case study, the following topics are addressed:
1. Defining a suitable vibration profile for shaker testing.
2. Integrating physical and virtual testing, including:
Deriving simulation parameters from vibration tests.
Verifying simulated fatigue predictions using physical test data.
3. Applying System-of-Systems reliability simulation to scale multiple dependent and independent failure modes, representing the overall reliability of complex battery systems.
4. Managing physical testing within a stage-gated product development cycle.
By improving simulation accuracy through validation, virtual testing reduces the need for physical prototypes while increasing confidence in reliability targets. Over time, this approach builds trust in simulation models, paving the way for Qualification by Simulation. The EV battery system example demonstrates how integrating physical and virtual testing can minimise warranty risks and support the development of reliable, sustainable technologies.
Director of Technology – nCode Products, HBK
Dr. Halfpenny has a PhD in Mechanical Engineering from University College London (UCL) and a Master’s in Civil and Structural Engineering. With over 25 years of experience in structural dynamics, vibration, fatigue and fracture, he has introduced many new technologies to the industry including: FE-based vibration fatigue analysis, crack growth simulation and accelerated vibration testing. He holds a European patent for the ‘Damage monitoring tag’ and developed the new vibration standard used for qualifying UK military helicopters.
He has worked in consultancy with customers across the UK, Europe, Americas and the Far East, and has written publications on Fatigue, Digital Signal Processing and Structural Health Monitoring. He sits on the NAFEMS committee for Dynamic Testing and is a guest lecturer on structural dynamics with The University of Sheffield.
This presentation will begin with a brief introduction to LDS by HBK, followed by an overview of fatigue and durability shaker testing, including HALT, HASS, and ESS methodologies. We will examine their purpose, practical considerations, and implications for product reliability.
Equally important is the reliability of the shaker system itself. How can we maximise shaker lifespan and ensure consistent performance? We will discuss the factors that influence armature life, identify which test types impose the greatest demands on the system, and highlight common practices that may reduce service life.
Finally, we will outline strategies to prevent premature wear, emphasising the importance of correct operation, system care, and proactive maintenance. By addressing both product and shaker reliability, this presentation aims to provide a comprehensive perspective on durability testing and long-term system performance.
Product Manager - Vibration Test Systems, HBK
Tim Gardiner joined Hottinger Brüel & Kjær in 2021. Tim has nearly 20 years of experience in product management and commercial leadership both in the UK and Europe with a background in test and measurement. Tim has responsibility for all VTS products that serve in the aerospace, automotive and defence industries, He has a business degree from the Solent University in the UK.
This session explores the use of statistical data models to better understand, predict, and manage product reliability. It introduces life data modelling techniques and statistical distributions, showing how they can be applied to forecast failure rates, evaluate warranty costs, and compare product generations or designs against reliability targets. These models become powerful tools for making reliability predictions more accurate, cost-effective, and representative of real-world performance.
Attendees will learn how fatigue life scatter is best characterised by a lognormal probability distribution, and how accelerated life models for multiple stressors can be used with accelerated life test results to estimate the life distribution of a population in service.
The session concludes with how design of experiments (DOE) methods can be used for probabilistic fatigue analysis in nCode, helping engineers quantify the effects of variability in loading, material properties, and environmental conditions.
Senior Application Engineer – Reliability, HBK
Mariusz is an application engineer supporting ReliaSoft reliability software for HBK with 18-years of professional experience in reliability engineering, with previous experience at Warsaw Institute of Aviation and General Electric in aviation and energy industries. Certified Six Sigma Black Belt focused on continuous improvement. Training instructor in reliability engineering. Specializes in reliability of nonrepairable systems and RAM analysis (Reliability, Availability, Maintainability). Project manager, currently implementing the FRACAS systems (Failure Reporting, Analysis and Corrective Action System).
The fatigue failure mechanism results in variability, or “scatter”, in experimental fatigue tests. This is because fatigue damage nucleates as a microstructural phenomenon, and no two specimens are the same at this scale. This is an aleatoric variability, it is irreducible, and is attributable to the inherent, or natural variability in the material microstructure. Fatigue testing standards and operating procedures exist to minimise all other variability arising from test specimen geometry and surface condition, with accurate and calibrated measurements, to best characterise material fatigue performance.
This presentation shows a study to determine whether fatigue test life scatter is best characterised by a Weibull or lognormal statistical distribution for a high strength steel commonly used for aircraft landing gear structures.
A review of HBK historical fatigue tests identified a large and homogeneous dataset for the same nominal material with the same magnitude constant amplitude fatigue tests conducted in different batches between 2000 and 2010. Comparison of lognormal and 2- and 3-parameter Weibull distributions concluded for this dataset that fatigue life scatter is best characterized by a lognormal distribution.
Application Engineer – Durability, HBK
Rob Plaskitt is an application engineer supporting nCode durability software for HBK. He has over 30 years of experience working as an engineer at HBK (formerly nCode) in areas of automotive, aerospace, defence and power generation. He has applied nCode software and technology in these industries from CAE concept design through full-scale testing, fleet monitoring, structural durability and vibration qualification. He has a first degree in Mechanical Engineering (Loughborough University) and a master degree in Structural Integrity (University of Sheffield).
This presentation describes quantitative accelerated life test analyses and why they are important. It shows how to develop an accelerated life model by combining a life model (or life distribution) with a life-stress relationship model from one or two simultaneous stressors. The resulting accelerated life model can be used with accelerated life test results to estimate the life distribution of a population in service. Case study examples are presented for one stressor in a temperature accelerated life test, and for two stressors in a temperature and voltage accelerated life test.
Senior Application Engineer – Reliability, HBK
Gabriele Serpi is a Certified Reliability Professional and holds an M.S. degree in Electronic Engineering. Gabriele works as Senior Application Engineer with HBK for 14 years. He has a broad experience in Weibull analysis, Accelerated Life Testing, RAM analysis, Standard Based Reliability Prediction, FMEA analysis and other reliability methodologies.
Design of experiments (DOE) is a tool to develop an experimentation strategy that maximizes learning using a minimum of resources. It is a general purpose structured method used to determine the relationship between factors affecting a process and the output of that process. It involves planning, conducting, analysing, and interpreting controlled tests or simulations to evaluate the effects of one or more variables simultaneously.
DOE provides a method for probabilistic fatigue analysis to systematically investigate how variability in loading conditions, material properties, geometry and/or other environmental factors affect estimated fatigue life. A DOE process can be divided two stages:
Stage 1 – Calculate an initial DOE design matrix based on a uniform random statistical distribution
Stage 2 – Reshape the initial design matrix to fit the required statistical distribution(s) for each factor
This presentation demonstrates probabilistic fatigue analysis in nCode using the Latin hypercube sampling method to ensure an even distribution of single or multi-variate random number “tests” in a design space for a uniform and Gaussian-normal distribution.
Application Engineer – Durability, HBK,
Rob Plaskitt is an application engineer supporting nCode durability software for HBK. He has over 30 years of experience working as an engineer at HBK (formerly nCode) in areas of automotive, aerospace, defence and power generation. He has applied nCode software and technology in these industries from CAE concept design through full-scale testing, fleet monitoring, structural durability and vibration qualification. He has a first degree in Mechanical Engineering (Loughborough University) and a master degree in Structural Integrity (University of Sheffield).
This session focuses on how advanced data management and analytics can transform durability engineering and structural health monitoring. It highlights methods for organizing and querying large, complex datasets from aerospace and automotive testing programs. Such diverse datasets are generated from physical testing environments and virtual simulations, for different test article configurations, and different operating conditions.
Attendees will see how these approaches extend into structural health monitoring applications for wind turbines and bridges, where integrated sensor data, cloud storage, and machine learning improve anomaly detection and predictive maintenance. Probabilistic fatigue modelling is introduced within these big-data infrastructures, showing how mission profiles and customer usage variability can be incorporated into life predictions using cloud-enabled workflows.
Together, these techniques demonstrate how smarter data handling enables engineers to accelerate decision-making, streamline workflows, and extract actionable insights, to improve reliability, reduce costs, and enhance long-term performance.
TBC
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Current automotive development demands the integration of large volumes of diverse datasets generated from physical testing environments, such as proving grounds, laboratory tests, and virtual simulations. Challenges lie in collating these datasets and organizing their files effectively across local, network and/or cloud storage platforms. To support cross-functional engineering teams, these datasets must be systematically stored, tagged, categorized, and made easily searchable.
As vehicle programs grow in complexity, the ability to rapidly query these datasets becomes essential. These queries may be based on vehicle programme, vehicle configuration, proving ground events, test locations, measurement locations, and/or statistical metrics. These capabilities enable engineers to develop laboratory test specifications, validate design changes, compare programme iterations, and generate inputs for computer-aided engineering (CAE) analyses.
Engineering apps are introduced, these enable subject matter experts to wrap up complex processes into easy-to-use web-based interfaces. Apps enable trend analysis, statistical breakdowns, durability validation, and more. They offer significant value to reduce vehicle development time and cost by streamlining workflows, accelerating decision-making, gaining engineering insights, and improving collaboration across engineering units.
Application Engineer, Durability, HBK
Anin Maskay is an Application Engineer at HBK, supporting HBK’s nCode software tools and conducting training courses with a focus on signal processing, durability analysis, and engineering analytics. Anin holds a Ph.D. in Electrical and Computer Engineering from the University of Maine, where his research focused on wireless sensors for high-temperature harsh environments, with applications in structural health monitoring and condition-based maintenance. Prior to joining HBK in 2021, Anin spent several years in research and development of sensors and data acquisition systems for aerospace and power generation industries.
TBC
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The ability to efficiently collect, manage, and analyze vast amounts of operational data is transforming how engineers approach maintenance and troubleshooting. This presentation explores the role of Aqira in two data management projects addressing challenges in structural health monitoring of wind turbines and bridges respectively. By integrating sensor data collection, cloud-compatible storage solutions, advanced vibration & durability analytics and machine learning algorithms, engineers can now detect anomalies, predict failures, and optimize maintenance schedules by leveraging nCode solutions.
Application Engineer, Durability HBK
Nicolas Sias is an Application Engineer at HBK, performing support, consulting, training and pre-sales for nCode (durability) and ReliaSoft (Reliability) software. He has experience in durability, vibration, reliability, maintainability and safety applied to system or component validation, and expertise in signal processing, statistical analysis, scientific programming, machine learning, and database management. He has a masters degree in Modélisation Mathématiques pour les Sciences de l'Ingénieur from University of Reims Champagne-Ardenne.
The durability and reliability qualification of components is based on analysis from many sources, sensors, CAN and IIOT data. These require data management infrastructure to collate their measurements to identify customer usage and variability. Such big data infrastructure, often called a data lake, may lead to storing huge quantities of data. This infrastructure must be generic and test data-oriented, to understand the data structure and its analysis required, and to be optimized for such application. These data may originate from connected equipment, instrumented fleets, test benches, proving ground measurements, digital twins and/or multi-body dynamics simulations. They must be managed in terms of quality and traceability, and indexed to be retrievable through request tags, such as customer, vehicle, measurement site, engine specification, road condition, usage conditions, etc.
The data lake can be analysed to derive mission profiles with equivalent damage, enabling characterisation of customer usage and input variabilities into probabilistic data models. These uncertainties on inputs (geometry, material and loading) may be propagated to fatigue life results, from their probability distribution functions, using a Monte Carlo analysis. The Aqira infrastructure proposes to launch multiple runs on cloud-oriented servers, to automatize and streamline the whole process. A use case is presented, to illustrate the approach, combining nCode durability analysis with ReliaSoft technology for probabilistic fatigue life prediction.
Senior Application Engineer, HBK
Amaury Chabod is Senior Application Engineer at HBK since 10 years, where he's performing support, training and pre-sales for nCode (durability) and ReliaSoft (Reliability) softwares. Previously, he has 10 years experience as FEA Engineer/Project Manager in components design and fatigue material testing projects.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
This will bring together HBM, Brüel & Kjær, nCode, ReliaSoft, MicroStrain and Discom brands, helping you innovate faster for a cleaner, healthier, and more productive world.
