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Aufsatz
Adapting Kano's Theory for weighting and implementing customers requirements on a software tool for assessing human reliability in manual assembly
(2018)
The following paper illustrates the conception of an Excel-based software tool developed to predict human error probabilities in manual assembly lines. In this regard, the paper clearifies how reliable risk analyses of manual work tasks can be carried out with the help of a software tool. Furthermore, to initiate a high user-friendliness, a high acceptance and a high level of dissemination, this paper deals with a Kano survey concerning customer requirements on the developed software tool. As a result, it will be ...
Aufsatz
Sensor Concept Based on Piezoelectric PVDF Films for the Structural Health Monitoring of Fatigue Crack Growth
(2011)
A new sensor concept for monitoring fatigue crack growth in technical structures is presented. It allows the in-situ determination of the position of the crack tip as well as the fracture mechanical quantities. The required data are obtained from a piezoelectric polymer film, which is attached to the surface of the monitored structure. The stress intensity factors and the crack tip position are calculated from electrical potentials obtained from a sensor array by solving the non-linear inverse problem.
Aufsatz
Crack path predictions and experiments in plane structures considering anisotropic properties and material interfaces
(2015-09-28)
In many engineering applications special requirements are directed to a material's fracture behavior and the prediction of crack paths. Especially if the material exhibits anisotropic elastic properties or fracture toughnesses, e.g. in textured or composite materials, the simulation of crack paths is challenging. Here, the
application of path independent interaction integrals (I-integrals), J-, L- and M-integrals is beneficial for an accurate crack tip loading analysis.
Numerical tools for the calculation of loading ...
Konferenzveröffentlichung
Concept for selecting and integrating traceability systems in the continuous improvement process of SMEs
(2019)
Industry 4.0 is characterized by digitization, globalized markets and a growing demand for individualized products. Therefore, the success of manufacturing companies heavily relies on innovative and customer driven products. However, the industrializing phase of such products is often characterized by the occurring of errors originating in a lack of experience. If errors are not detected prior to delivery, costs will increase considerably (e.g. expensive product recalls). Traceability systems can clearly identify the ...
Dissertation
Development of CFD-Based Tip Clearance Loss and Deviation Models for Axial-Flow Turbines
(2020-01)
Accurate loss correlations are crucial for reliable turbine performance predictions with low-fidelity tools. However, conventional tip clearance models disregard some important loss effects, e. g. from the relative motion between blades and endwall, and their natural spanwise distributions, which are valuable for through-flow methods. The objective of this thesis is the development of more realistic tip clearance models by means of high-fidelity CFD simulations, which capture all three-dimensional flow effects and ...
Preprint
Annual industrial and commercial heat load profiles: modeling based on k-Means clustering and regression analysis
(2021-03-19)
An accurate method to predict annual heat load profiles is fundamental to many studies, e.g., preliminary design or potential studies on renewable heating systems. This study presents a method to predict annual heat load profiles with a daily resolution for industry and commerce, based on an analysis of 800 natural gas load profiles (≥ 1.5 GWh/a). To derive heat load profiles, these natural gas load profiles are normalized and those with a potentially non-linear relationship between heat demand and natural gas ...
Aufsatz
Increasing energy efficiency of milk product batch sterilisation
(2018-09-07)
The food industry is a large energy consumer and most heat demands in food processing are low-temperature. The aim of this study is to develop and simulate innovative retrofits or redesigns that unlock the heat recovery potential of industrial batch sterilisation processes. The case study focuses on the whey cream process, although the method and results apply to similar batch sterilisation processes. The initial situation is compared to energy efficient designs based on “Energy Storage” and “Rescheduling”. Using a ...
Aufsatz
Weak and strong bi-material interfaces and their influence on propagating cracks in plane elastic structures
(2017-09-06)
The developing crack paths in heterogeneous structures are the result of the inhomogeneous state of stress. The latter stems from e.g. voids or inclusions in an elastic matrix, which are bonded either by strong or weak interfaces. Besides the stiffness of an inclusion, the kind of interface has a decisive influence on the state of stress and therefore on propagating cracks. It is experimentally proven that cracks tend to grow towards regions with lower stiffness (Tilbrook et al., 2006; Judt et al., 2015), therefore ...
Aufsatz
Crack Paths at Multiple-crack Systems in Anisotropic Simulation and Experiment
(2014-06-27)
This paper is targeted on numerical methods for accurate crack tip loading analysis and crack path prediction. Those are based on finite element calculations of the boundary value problem. Applying path-independent integrals to curved cracks in order to accurately calculate the J-integral, energy release rate (ERR) or stress intensity factors (SIF) is still not state of the art. Contours which are not confined to the crack tip require special analytical preparation and numerical treatment to supply results which are ...
Aufsatz
Signal based non-intrusive load decomposition
(2019-05-29)
Driven by both regulatory and monetary interests the development of energy monitoring systems has been accelerated in recent years. Thus, a large amount of data is collected and stored in huge databases. This is a decisive step towards sustainable production systems since you can’t improve what you don’t know. This paper aims to use the datasets currently available and to combine databases to gather additional information on production systems, in particular energy flows. Therefore, an algorithm has been developed ...