Open Access Zeitschriften des Universitätsverlages der Technischen Universität Chemnitz
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Numerical Simulation of Joining Ropes by Sewing Stitches
Get PDFBraided structures are widely used in numerous contexts including everyday practice. In most cases, rope ends are knotted to form various types of loops or tie them to rigid body parts; however, knots take up space that may not be available in some application scenarios, thus making them unsuitable for certain purposes. Hence, this paper introduces first development steps of a method for the numerical simulation of rope ends connected by sewing stitches
Numerical simulation of fiber-matrix debonding in single fiber pull-out tests
Get PDFThe present work deals with the numerical crack simulation of fiber-matrix debonding in single fiber pull-out tests. For this purpose, two models are used: a finite element model (FE model) with the cohesive zone approach and a peridynamic model. For calibration a reference experiment is applied. In addition analytical equations are used for reference values. The influence of the model parameters and the material parameters of the cohesive zone model on the force-displacement curve is investigated. Besides the free fiber length, the critical interface strength, the critical energy release rate as well as the initial interface stiffness have a great influence on the force-displacement curve of the pull-out test. From the crack simulation it can be seen that Mode I has an influence on the crack initiation, but further crack growth after initiation is dominated by Mode II. The FE model can be calibrated in a way that the crack initiation point and the maximum force correspond to the reference experiment. The peridynamic model depicts a comparable crack formation process
Research in Sustainability of Chain Conveyor Systems
Get PDFClimate Change is a crucial challenge of today. The main reason is increased man-made emissions of climate gases, like CO2, into the atmosphere. In every part of our life, these emissions have to be reduced. Transport of goods, called intra- or extralogistics, is necessary for economic welfare. Intralogistics means the transport of goods in distribution centres or manufacturing spaces, e. g. between machines. For continuous transport processes chain conveyor systems (CCS) are state of the art. The research group “Plastic Components and Tribology” at professorship of Conveying Engineering and Materials Handling focus on impacts of their whole life cycle, from design over use until end-of-life, on the environment. Another focus is the development of Environmental Product Declaration (EPD) for chain conveyor systems. They are useful to promote environmentally-friendly products and to push eco-design activities. But also, activities of circular economy such as recycling of the plastic parts from conveyor chains are examined. The article gives an overview of the goals achieved and the challenges ahead. Some of the achieved results will be presented
Real-time Measuring and Monitoring of Relevant Parameters in Complex Chain Conveyor Systems
Get PDFIn continuous conveyor systems with circulating traction mechanisms, e.g. chains, the kinematic-dynamic movement behaviour of the traction mechanism is of great importance. Force and vibration analyses can be used to detect overloads and other irregularities in the conveying process. This helps to prevent damage that can lead to a complete failure of the conveyor system. Such analyses are particularly interesting for slide chain conveyors with plastic chains, as these react very sensitively to system overload due to limited thermal and mechanical characteristics as well as often a complex track layout. This article shows how accelerations and tractive forces can be continuously recorded, transmitted and analysed by sensors integrated into the chain links. In addition to the discussion of test results, potential applications of the measuring chain are shown
Towards Robust Situation Awareness in Autonomous Vehicles
Get PDFAutomotive Industry is having a rapid progress towards highest level of autonomy. As the industry moves up the ladder of automation, safety features are coming more and more into the focus. Different safety measurements have to be taken into consideration based on different driving situations. One of the major concerns of the highest level of autonomy is to obtain the ability of understanding both internal and external situations. In order to automate this process, first, understanding and automating the situation identification is necessary. Systems will also have to have embedded intelligence of awareness in order to reach to these situations. Situation Awareness is a term that consists of extracting information from the environment, providing an understanding towards the extracted features and taking actions in order to make awareness. This journal focuses on the different levels of situation awareness, provides concepts in order to automate the process so that it can play a vital role towards highly autonomous vehciles
Methods for Determining the Modulus of Elasticity of Wire and Fibre Ropes
Get PDFDetermining, evaluating and thus knowing the rope modulus of elasticity is vital for a number of applications. Several measurement methods can be used and the evaluation of the results can also be realized in different ways. This article tries to give an overview, mentions the important characteristics of the complete process and highlights two measurement methods used at IFT. The methods are compared regarding their usage and measurement accuracy for both steel wire and fibre ropes
Kunststoffgleitlager mit intelligenter Verschleißüberwachung
Get PDFDie Zustandsüberwachung (Condition Monitoring) und die vorausschauende Wartung (Predicted Maintenance) gelten als Schlüsselinnovationen der Industrie 4.0. Im Zuge dessen arbeiten Forscher der Professur Intelligente Maschinensysteme an der Hochschule Mittweida an einem Kunststoffgleitlager, welches eine integrierte Sensorik besitzt, die dem Anwender die Überwachung von Betriebsdaten ermöglichen soll. Die aus einem elektrisch leitfähigen Kunststoff hergestellte Sensorik trägt dazu bei, dass in Echtzeit sowohl eine Aussage zur Lagertemperatur als auch zum Verschleißgrad des Lagers getroffen werden kann. Damit lassen sich Wartungsintervalle besser planen und ein prophylaktischer Austausch von noch gebrauchsfähigen Lagern kann vermieden und damit Kosten gesenkt werden. Dafür sind umfangreiche numerische Untersuchungen zum mechanischen, thermischen und elektrischen Verhalten der Sensorik bzw. des Gleitlagers mit Interaktion der Welle durchgeführt worden. Dies beinhaltet auch eine Auswahl möglicher Werkstoffe. Außerdem ist die Auswerteelektronik (Messwertverstärkung, Datenverarbeitung und Datenübermittlung) entsprechend den Anforderungen der Sensorik entwickelt wurden. In einem weiteren Schritt wurde ein Funktionsmuster des Kunststoffgleitlagers mittels FDM-Drucks hergestellt
Artificial Intelligence & Machine Learning in Computer Vision Applications
Get PDFDeep learning and machine learning innovations are at the core of the ongoing revolution in Artificial Intelligence for the interpretation and analysis of multimedia data. The convergence of large-scale datasets and more affordable Graphics Processing Unit (GPU) hardware has enabled the development of neural networks for data analysis problems that were previously handled by traditional handcrafted features. Several deep learning architectures such as Convolutional Neural Networks (CNNs), Recurrent Neural Networks (RNNs), Long Short Term Memory (LSTM)/Gated Recurrent Unit (GRU), Deep Believe Networks (DBN), and Deep Stacking Networks (DSNs) have been used with new open source software and libraries options to shape an entirely new scenario in computer vision processing
Real-time 3D Perception of Scene with Monocular Camera
Get PDFDepth is a vital prerequisite for the fulfillment of various tasks such as perception, navigation, and planning. Estimating depth using only a single image is a challenging task since the analytic mapping is not available between the intensity image and its depth where the features cue of the context is usually absent in the single image. Furthermore, most current researchers rely on the supervised Learning approach to handle depth estimation. Therefore, the demand for recorded ground truth depth is important at the training time, which is actually tricky and costly. This study presents two approaches (unsupervised learning and semi-supervised learning) to learn the depth information using only a single RGB-image. The main objective of depth estimation is to extract a representation of the spatial structure of the environment and to restore the 3D shape and visual appearance of objects in imagery
Camera-based Visual Rope Inspection
Get PDFThe manual visual inspection of ropes, both wire and fibre ropes, is still the preferred method of choice for the inspection of suspension means and for safety assessment. As the ropes are usually of a longer length of several hundred metres, manual visual inspection can lead to undetected defects due to inspector fatigue. On the other hand, the inspector only sees the surface facing him and there is no recorded data of the inspection that can be used for clarification in case of a rope breakage. Due to these points, it is advantageous to perform an automated camera-based inspection where several cameras are arranged around the rope. Especially with high modular fibre ropes, which are used in more and more fields of application, visual inspection is a decisive point in the evaluation of operational safety. IFT is currently conducting and has conducted research projects in this field of work