Martin Dazer

• Doctor of Engineering
• Head of Department at University of Stuttgart

This paper introduces the so-called Sustainability-Usage Ratio (SUR), relating the Global Warming Potential (GWP) of a product to the duration of its use and it introduces an approach for evaluating the SUR. To this end, two principal methods are presented: one based on the arithmetic mean usage and another integrating over the product's GWP curve...

Using an autoencoder (AE) based approach enables damage detection in a very early stage and does not require labeled training data. The earliest possible damage detection in gearboxes provides a precise insight into the state of health. The aim of this investigation is to use extended training datasets that include multiple operating conditions, th...

The planning of reliability demonstration tests is a typical task for reliability engineers. To find the optimum test plan, many different scenarios must be considered and compared. Comparing test plans by their estimation variance has several disadvantages, as it only considers the type I error. To overcome these disadvantages, the probability of...

Gearbox failure in offshore wind turbines can be caused by fatigue damages like tooth flank fracture (TFF) or pitting damage. For damage detection in current applications, simple threshold values for vibration amplitudes are used to initiate a shutdown of the wind turbine. At this time significant damage to the gear is already present and an extern...

Adaptive systems can adjust to changing conditions. When this adaptability is associated with changes in shape, force or stress, the load-bearing structures can be made slimmer, can achieve longer service life and/or cause less CO2 emissions. However, adaptation functions can fail, and in the worst case, they may act contrary to the desired behavio...

Condition monitoring with very early gear damage detection enables remaining useful life prediction and health management of drive units. For a reliable detection of tooth flank damage during operation, a holistic approach combines experimental investigations, physical and AI-based data evaluation and is supplemented by FE and multi-body simulation...

Prognostics and Health Management (PHM) offers the potential to increase the acceptance of adaptive structures and to operate them in an optimal way. With suitable design and proper operation, adaptive high-rise structures enable significant increases in sustainability and service life extensions compared to passive high-rise buildings. The control...

Early damage detection in gearbox applications enables the implementation of Prognostics and Health Management (PHM). On the one hand, the earliest possible damage detection provides a precise in-sight into the state of health of a gearbox. In addition, early damage detection offers the possibility to slow down the damage progress and extend the re...

Absence of failure data is a common challenge for data-driven predictive maintenance, particularly in the context of new or highly reliable systems. This is especially problematic for system level failure prediction of analog electronics since failure characteristics depend on the actual system layout and thus might change with system upgrades. To...

The economic efficiency of machinery operation is significantly impacted by maintenance strategies. In the realm of condition-based or predictive maintenance strategies, the early detection of fatigue-induced damages is crucial. Therefore, this study focuses on the early detection of pitting damages during operation. Experimental investigations are...

This investigation comprehensively compared the elastic contact and the modified stiff impact models, aiming for the backlash-induced nonlinear vibro-impact gear rattle under lightly loaded conditions. Three meshing force models in backlash are incorporated into the elastic model independently. Unlike the previous uncoupled stiff impact model, the...

Modern vehicles have increasing safety requirements and a need for reliable low-voltage power supply in their on-board power supply systems. Understanding the causes and probabilities of failures in a 12 V power supply is crucial. Field analyses of aged and failed 12 V lead batteries can provide valuable insights regarding this topic. In a previous...

Machine learning algorithms enable failure prediction of large-scale, distributed systems using historical time-series datasets. Although unsupervised learning algorithms represent a possibility to detect an evolving variety of anomalies, they do not provide links between detected data events and system failures. Additional system knowledge is requ...

For the investigation of influence of various parameters on properties and outputs of components or systems, Design of Experiments (DOE) offers the most efficient approach to create a comprehensive empirical insight into product performance. However, especially if product lifetime is treated as the investigation objective, the main focus of attenti...

Orthogonality in DoE favors non-correlated effects and minimizes their confidence intervals. However, accidental or deliberate deviation from orthogonality is often possible on the one hand, and sometimes even desirable within reliability demonstration testing. Based on an investigation of orthogonality deviations (errors in factor levels) with res...

This investigation comprehensively compared the elastic contact and the modified stiff impact models, aiming for the lightly loaded backlash-induced gear rattle. Three meshing force models in backlash are incorporated into the elastic model independently. Unlike the previous uncoupled stiff impact model, the modified impact model considers the coup...

Die Bilanzierung von Umweltwirkungen spielt eine entscheidende Rolle bei der Entwicklung nachhaltiger und umweltfreundlicher Technologien und Konzepte. Dies gilt auch in der Entwicklung von Gebäuden mit adaptiven Hüllen und Strukturen und stellt darüber hinaus weitreichende Anforderungen an alle beteiligten Disziplinen. Die vollständige Integration...

Many failures of wind turbines are due to drive failures caused by pitting. Each failure can be associated with high repair costs and time-consuming repair work. This particularly applies to offshore facilities. For these reasons, increasing the remaining useful life of wind power drives is essential to leave a minimal ecological footprint by simul...

Vorwort Sehr geehrte Damen und Herren, durch die zunehmende Digitalisierung, Autonomisierung und Vernetzung von technischen Systemen, beispielsweise in einer Smart Factory im Kontext von Industrie 4.0 oder in autonomen Fahrzeugen, werden hohe Anforderungen an die Zuverlässigkeit, die Verfügbarkeit und die Sicherheit dieser Systeme gestellt. Dies er...

Vorwort Sehr geehrte Damen und Herren, durch die zunehmende Digitalisierung, Autonomisierung und Vernetzung von technischen Systemen, beispielsweise in einer Smart Factory im Kontext von Industrie 4.0 oder in autonomen Fahrzeugen, werden hohe Anforderungen an die Zuverlässigkeit, die Verfügbarkeit und die Sicherheit dieser Systeme gestellt. Dies er...

To cope with the megatrends electrification, automated driving, and connectivity, new functionalities and electric and/or electronic systems must be developed, which require a safe power supply. This leads to increased functional safety requirements for the power supply system, particularly regarding availability. Fault tolerance measures can be im...

In critical industrial applications, gearboxes are already equipped with Condition Monitoring Systems (CMS) based on vibration sensors. However, these systems are only developing their full potential if damages can be detected early and if the accumulated sensor data can be assigned to a type of damage and a damage size. The aim of this investigati...

Empirical life tests are used for reliability demonstration and determination of the actual reliability of the product. Therefore, engineers are faced with the challenge of selecting the most suitable test strategy out of the possible many and also the optimal parameter setting, e.g. sample size, in order to realize reliability demonstration with l...

In diesem Kapitel werden die Attribute Sicherheit, Zuverlässigkeit und Qualität detaillierter vorgestellt, mit denen die Erfüllung der Anforderungen durch die Produktattribute beurteilt werden kann. Das Zusammenspiel der drei Attribute wird in den Abschn. 3.2.2 und 3.4 beschrieben.

Um Betriebskosten und Stillstandszeiten durch ungeplante Ausfälle zu reduzieren, ist eine gute Instandhaltbarkeit technischer Produkte, Anlagen oder Systeme notwendig. Insbesondere bei Investitionsgütern wie beispielsweise Produktionsanlagen spielt deshalb die Instandhaltbarkeit der Systeme eine wichtige Rolle. Qualitativ beschreibt die Instandhalt...

Die Bilanzierung von Umweltwirkungen spielt eine entscheidende Rolle bei der Entwicklung nachhaltiger und umweltfreundlicher Technologien und Konzepte. Dies gilt auch in der Entwicklung von Gebäuden mit adaptiven Hüllen und Strukturen und stellt darüber hinaus weitreichende Anforderungen an alle beteiligten Disziplinen. Die vollständige Integration...

Due to the possible damage caused by unforeseen failures of safety-critical systems, it is crucial to maintain these systems appropriately to ensure high reliability and availability. If numerous units of a system are installed in various areas and permanent access is not guaranteed, remote, data-driven condition monitoring methods can be used to s...

In the context of design of experiments (DoE), for many cases the quantitative dependency of a nonlinear target parameter on a few factors is to be determined for the related parameter prediction. For these cases, from the group of response surface designs, test plans are used following the structure of Central-Composite Design (CCD). Their leverag...

Planning reliability demonstration tests is particularly complex if end-of-life tests are used instead of standard success run tests. In addition to the factors of cost and time, the probability of test success can be used to select the optimal test strategy. This has already been considered for a single-stage load in several papers. In real applic...

Statistical power analyses are used in the design of experiments to determine the required number of specimens, and thus the expenditure, of a test. Commonly, when analyzing and planning life tests of technical products, only the confidence level is taken into account for assessing uncertainty. However, due to the sampling error, the confidence int...

Technical systems have to be designed that the requirements regarding service life are met with high reliability to ensure safe product operation. In many cases, the design is still based on single events, such as extreme load levels and additional safety factors, in order to ensure reliability, which is accompanied by a high degree of oversizing....

Over the past decades, product development cycles have become shorter and shorter, with reliability requirements increasing while budgets for testing have decreased. To select a test that makes the best use of resources (cost and time) for reliability requirement with a sufficient level of confidence, a simulation is performed. In previous work by...

The consumption of construction materials and the pollution caused by their production can be reduced by the use of reliable adaptive load-bearing structures. Adaptive load-bearing structures are able to adapt to different load cases by specifically manipulating internal stresses using actuators installed in the structure. One main aspect of qualit...

The automotive industry is currently driven by the megatrends electrification, automated driving and connectivity. To cope with these trends, new functionalities and electrical and/or electronic (E/E) systems need to be developed and deployed. Independent of the implementation of E/E systems, their power input shall be ensured by the power supply s...

The automotive industry is currently driven by the megatrends electrification, automated driving, and connectivity. To cope with these trends, new functionalities and electric and/or electronic systems must be developed, which require a safe power supply by the power supply system. This leads to increased functional safety requirements for the powe...

To cope with the megatrends electrification, automated driving, and connectivity, new functionalities and E/E systems must be developed, which require a safe power supply. This leads to increased functional safety requirements for the power supply system, particularly regarding availability. Fault tolerance measures can be implemented to comply wit...

Within this work, the potential of an operating strategy is analysed based on test runs in laboratory environment, field tests as well as simulations. The operating strategy is used to increase the remaining useful life of gear wheel pitting by reducing the local stress at the weakened tooth. The local stress reduction is achieved by applying an ad...

Aus dem Vorwort: Durch die zunehmende Digitalisierung und Vernetzung, beispielsweise in einer Smart Factory im Kontext von Industrie 4.0, werden hohe Anforderungen an die Zuverlässigkeit, die Verfügbarkeit und die Sicherheit von Maschinen und Anlagen gestellt. Dies erfordert den konsequenten Einsatz und die ständige Weiterentwicklung von Methoden u...

Aus dem Vorwort: Durch die zunehmende Digitalisierung und Vernetzung, beispielsweise in einer Smart Factory im Kontext von Industrie 4.0, werden hohe Anforderungen an die Zuverlässigkeit, die Verfügbarkeit und die Sicherheit von Maschinen und Anlagen gestellt. Dies erfordert den konsequenten Einsatz und die ständige Weiterentwicklung von Methoden u...

The design of screw connections is subject to standardized calculation recommendations based mainly on empirically determined parameters with defined material characteristics. Here, a probabilistic extension of this design methodology for strength design against static load is proposed, whereby probability density functions of characteristic compon...

In this article, a procedure for the application of virtual sensors for load-related sizing and lifetime prognosis of components of large diesel engines is presented. Due to high costs for testing to assure the lifetime of a large diesel engine, the knowledge about the load is of utmost importance. The approach consists of several steps beginning w...

In order to reduce operating costs and downtimes due to unplanned outages, good maintainability of technical products or systems is necessary. The maintainability of of the systems therefore plays an important role, especially for capital goods such as production plants. In qualitative terms, maintainability describes the ease with which maintenanc...

In this chapter, the attributes safety, reliability and quality are presented in more detail, with which the fulfilment of the requirements can be assessed by the product attributes. The interaction of the three attributes is described in Sects. 3.2.2 and 3.4.

Within this work we introduce an operating strategy to increase the remaining useful life of gear wheels referring pittings. Aim of the strategy is the constant power of the transmission, as the power is splitted between weak and strong teeth. Therefore each tooth is considered equally within the lifetime estimation. To investigate the theoretical...

Die Arbeit beschäftigt sich mit der Lebensdauerberechnung bei der Schadensart Grübchen bei Zahnrädern. Hier wird eine Methode vorgestellt, welche die Prognose der Lebensdauer nicht anhand des Gesamtsystems Zahnrads vornimmt, sondern die einzelnen Zähne bewertet. Die-ses Vorgehen bietet die Chance, das Potential einer entwickelten PHM-Betriebsstrate...

Emerging markets are rapidly growing. Manufacturing systems in these markets have to be cost-effective but still of high quality. In addition they are often exposed to harsh conditions e.g. climate, infrastructure and lack of knowledge. Consequently, local conditions as well as reliability and robustness methods must be explicitly taken into accoun...