Anke Stoll

FDTech · AI - Machine Learning & Big Data

Process cooling is crucial to many manufacturing processes. To monitor the performance of a cooling tower, it was equipped with extensive sensors for internal and environmental data acquisition. The aim is to improve reactive and predictive maintenance by estimating the actual condition as well as predicting defective behavior of the cooling tower....

Systematic decision making in engineering requires appropriate models. In this article, we introduce a regression method for enhancing the predictive power of a model by exploiting expert knowledge in the form of shape constraints, or more specifically, monotonicity constraints. Incorporating such information is particularly useful when the availab...

Currently, the growth of material data from experiments and simulations is expanding beyond processable amounts. This makes the development of new data‐driven methods for the discovery of patterns among multiple lengthscales and time‐scales and structure‐property relationships essential. These data‐driven approaches show enormous promise within mat...

We present a regression method for enhancing the predictive power of a model by exploiting expert knowledge in the form of shape constraints, or more specifically, monotonicity constraints. Incorporating such information is particularly useful when the available data sets are small or do not cover the entire input space, as is often the case in man...

Currently, the growth of material data from experiments and simulations is expanding beyond processable amounts. This makes the development of new data-driven methods for the discovery of patterns among multiple lengthscales and time-scales and structure-property relationships essential. These data-driven approaches show enormous promise within mat...

Efficient response to machine failures is crucial for improving machine availability. In practice, the number of alarms occurring during the operation of manufacturing systems could overwhelm even experienced machine operators. Manufacturing execution systems (MES) therefore often allow for alarm data acquisition as well as its filtering and aggreg...

Machine learning, big data and deep learning are today’s catchphrases for how to improve reliability and productivity of your manufacturing equipment. Production companies implement a large number of sensors to record every activity within their production lines and learn as much as possible about their running processes in order to predict shiftin...

Due to the advances in the digitalization process of the manufacturing industry and the resulting available data, there is tremendous progress and large interest in integrating machine learning and optimization methods on the shop floor in order to improve production processes. Additionally, a shortage of resources leads to increasing acceptance of...

Today, the optimization of the press hardening process is still a complex and challenging task. This report describes the combination of linear regression with least squares optimization to adjust the process parameters of this process for quality improvement. The FE simulation program AutoForm was used to model the production line concerned and va...

Techniques for intraoperative radiation therapy (IORT), the applications of tumor bed radiation immediately after surgery or utilising intracavitary access, have evolved in recent years. They are designed to substitute or complement conventional external beam radiation therapy in selected patients. IORT has become an excellent treatment option beca...

Modelling the mechanical behaviour of biological tissues is of vital importance for clinical applications. It is necessary for surgery simulation, tissue engineering, finite element modelling of soft tissues, etc. The theory of linear elasticity is frequently used to characterise biological tissues; however, the theory of nonlinear elasticity using...

The aim of this article is to study the mechanical properties of the pancreas. Up to now, the mechanical properties of the pancreas are not sufficiently characterized. The possibility of intraoperative mechanical testing of pathological pancreata will allow the classification of pancreatic diseases in the future. The application of mechanical param...

Purpose: For a better understanding of the effects of thermally altered soft tissue, the biothermomechanics of these tissues need to be studied. Without the knowledge of the underlying physical processes and the parameters that can be controlled clinically, thermal treatment of cancerous hepatic tissue or the preservation of liver grafts are based...

A discrete dislocation model was used to simulate residual stress fields close to deformation twins in stainless steels. Dislocation pairs were distributed along an initially elliptical twin boundary and an iterative scheme used to allow the dislocations to relax towards positions where the internal shear stresses were below a friction stress. The...

The preservation time of a liver graft is one of the crucial factors for the success of a liver transplantation. Grafts are kept in a preservation solution to delay cell destruction and cellular edema and to maximize organ function after transplantation. However, longer preservation times are not always avoidable. In this paper we focus on the mech...

A dislocation-based boundary element model was used to simulate intergranular stress corrosion crack propagation in virtual microstructures. A Monte Carlo approach was used in which the propagation of approximately 100 cracks was calculated for different Voronoi generated microstructures. At every simulation step the model gave the position of the...

A dislocation model for simulating two-dimensional quasi-static crack propagation is presented. The crack and plastic flow along slip planes are described using dislocation dipoles. A stationary crack can be modeled as well as a propagating crack along a straight line inclined at an arbitrary angle to a free surface of a semi-infinite medium. Crack...

Der Grat wird in der DIN ISO 13715 als „Materialüberhang außerhalb der ideal-geometrischen Form einer Außenkante, die nach der mechanischen Bearbeitung oder einem Formgebungsprozess zurückbleibt“ [1] genormt. Dieser Grat wirkt sich durch seine Geometrieungenauigkeit und durch seine undefinierte Festigkeit negativ auf die Qualität des Bauteils aus....

Because of increased productivity demands in manufacturing the attention in burr problems is steadily turned to the avoidance of burr. With this initial point this paper contributes to the analysis and simulation of burr separation at workpiece material AISI 1045 steel (C45E). At first 12 known crack initiation criteria are investigated whether the...

Mit dem Ausgangspunkt, dass aufgrund erhöhter Produktivitätsanforderungen in der Fertigung das Augenmerk in der Gratproblematik zunehmend auf die Vermeidung von Grat gelegt wird, stellt diese Arbeit einen Beitrag zur Analyse und Simulation des Abreißens von Grat am Werkstoff Ck45 dar. Dies geschieht vor dem Hintergrund, dass aufgrund sehr geringer...

Abstract Any kind of machining process leads to unintentional burr. To avoid or at least minimize burr, hybrid methods for analyzing burr formation have been investigated. A very important aspect of this investigations is the downscaling of the machining process and its influence on burr formation, in particular to locate nonlinearities. The sca...

Modelling of size-effects in burr-formation