Defects like folds can arise using forging for the production of long flat pieces made of aluminium. A special defect is the formation of inner folds. These can be seen in the grain flow. Inner folds have a negative effect on the dynamic properties of the forged part. As a production process, forging can be divided into single-directional and multi-directional forging. The formation of inner folds was observed at the single-directional forging. By using the multi-directional forging, a forming operation working from different directions, the forming can be set variably. Thus the development of folds can be prevented. A newly developed method can help in the selection of the forming process and in determining an appropriate tool geometry. Here especially the area is adapted, where the development of inner folds occur. Therefore a calculation model was developed. It integrates a computer-aided identification of the inner folds. Using this model, a correction of the parametrically constructed forging tool is possible.
multidirectional-forging, long flat pieces, aluminium, fibre orientation
In the forging industry, which is dominated by SMEs, the tool life of forging dies is usually determined on the basis of empirical values and subjective decisions. In order to avoid considerable logistical and economic expenses as a result of unplanned downtimes and die failure, the tool life is often set many times lower and a waste of existing residual tool life is caused. One possibility to determine the remaining tool life of forging tools is a combined measuring method, which is to be developed at the Institut für Integrierte Produktion Hannover (IPH) gGmbH.
Forming technology, tool life, process monitoring
The manual handling of forged parts is physically demanding for forging employees. These physical stresses are reflected in damage to the hand-arm system and back and lead to forging employee absenteeism. In order to protect the health of forging employees, the aim is to reduce the basic stress caused by the dead weight of the forging tongs by using lightweight forging tongs.
forging tongs, ergonomics, lightweight design
Flat die rolling is a solid forming operation, in which two engraved tool plates run past each other and thereby form a cylindrical semi-finished product. The non-circular rolling can be used as a preform optimising process, where it should be possible to form local non-circular sections, for example ellipses or eccentrics, into a cylindrical semi-finished product. The material flow should be exclusively in radial direction. Initial simulations show that the requirements can be met.
non-circular rolling, cross wedge rolling, flat dies, preforms and intermediate forms, FEM
The development of a method for the optimal planning of the relocation of factory objects is being addressed by the IPH - Institut für Integrierte Produktion Hannover gGmbH within the framework of a research project. The design of a relocation plan, taking into account temporal and spatial restrictions, represents a complex planning problem. The method to be developed enables a comprehensive evaluation of a relocation plan with regard to different target criteria. The mathematical optimisation model is to be implemented with the help of a heuristic solution procedure. The intuitive implementation within a software environment further supports the easy applicability.
Factory Planning, Relocation, Project Scheduling, Preparation for Realisation, Operations Research
Since free?aces for new buildings are limited or not available at all, redensification is a promising approach to generate new living space. This can be both the extension of existing buildings by further storeys and the vertical extension or change of use of other building structures. Modular house construction takes this objective into account because a large part of the added value is generated before construction begins. Its advantages are now set against the logistical challenges of post-densification.
Modular house construction, post-densification, construction sites, production planning and control
On inner-city construction sites, there is usually only a limited amount of space available. This increases the complexity in the implementation of corresponding construction projects and at the same time the risk of postponements. Both the composition of the demand for specific types of space and the development of demand during the construction period should be taken into account in the course of scheduling. One way of assessing the demand for space is to introduce the potential for conversion as an indicator of the property of a specific space to be able to adapt flexibly in the event of possible short-term changes in the construction project. This can be used to create an evaluation basis that initially provides decision support for project planners and can subsequently be integrated into optimising procedures for scheduling. This will have a positive influence on the quality of a schedule in connection with its robustness.
Scheduling, construction management, project planning, production planning, construction sites
Multi-stage forging process chains are often used for the efficient production of complex geometries. Typically, these consist of homogeneous heating, one or more preform stages, and the final forging step. By inhomogeneously heated billets, the process chains can be simplified or shortened. This shall be achieved by setting various temperature fields within a billet, resulting in different yield stresses. These can influence the material flow, leading to easier production of complex parts. In this study, the influence of inhomogeneously heated billets on the forming process is investigated by means of FEA. For this purpose, two process chains including inhomogeneous heating and three homogeneously heated reference process chains are developed and compared. Each process chain is optimized until form filling and no defects occur. Target figures for the assessment are necessary forming force, the amount of material necessary to achieve form filling and die abrasion wear. For process chains with inhomogeneously heated billets, the results showed a small time window of about 5 s for a successful forming in terms of form filling. Forming forces and die abrasion wear increase for inhomogeneously heated billets due to higher initial flow stresses. However, the flash ratio decreases when billets are heated inhomogeneously. Depending on their size, inhomogeneously heated billets show up to 11.8% less flash than homogeneously heated billets. This shows a potential for the use of inhomogeneous heating to make forging processes more efficient. Subsequently, experimental tests will be carried out to verify the results of the simulations.
Inhomogeneous heating, Forging, FEA, Resource efficiency, Preform operation
To increase the economic efficiency in the production of geometrically complicated forgings, material efficiency is a determining factor. In this study, a method is being validated to automatically design a multi-staged forging sequence initially based on the CAD file of the forging. The method is intended to generate material-efficient forging sequences and reduce development time and dependence on reference processes in the design of forging sequences. Artificial neural networks are used to analyze the geometry of the forging and classify it into a shape class. Result of the analysis is information on component characteristics, such as bending and holes. From this, special operations such as a bending process in the forging sequence can be derived. A slicer algorithm is used to divide the CAD file of the forging into cutting planes and calculate the mass distribution around the center of gravity line of the forging. An algorithm approaches the mass distribution and cross-sectional contour step by step from the forging to the semi-finished product. Each intermediate form is exported as a CAD file. The algorithm takes less than 10 min to design a four-stage forging sequence. The designed forging sequences are checked by FE simulations. Quality criteria that are evaluated and investigated are form filling and folds. First FE simulations show that the automatically generated forging sequences allow the production of different forgings. In an iterative adaptation process, the results of the FE simulations are used to adjust the method to ensure material-efficient and process-reliable forging sequences.
Automatic process design, Forging, FEA, Resource efficiency, CAD
A method is presented that enables the complexity of a forging to be determined automatically on the basis of the CAD file of the forging. An automated evaluation of the forging complexity is necessary for a digitized and automated design of stage sequences in order to be able to determine important design parameters such as the flash ratio or the number of stages.
CAD, forming technology, algorithms
The compilation of information for the processing of internal production tasks is often based on less-questioned route sheet templates. The selection of the optimal amount and depth of information requires a positioning in an area of conflict between the amount of work in the planning process and the benefit in the execution. Therefore, a method to quantify and evaluate the level of detail of different information individually is presented. Thus a basis is created to determine the optimal level of detail in route sheets.
route sheets, work preparation, level of detail, provision of information, MES-implementation
Qualitative uncertainties are a key challenge for the further industrialization of additive manufacturing. To solve this challenge, methods for measuring the process states and properties of parts during additive manufacturing are essential. The subject of this review is in-situ process monitoring for material extrusion additive manufacturing. The objectives are, first, to quantify the research activity on this topic, second, to analyze the utilized technologies, and finally, to identify research gaps. Various databases were systematically searched for relevant publications and a total of 221 publications were analyzed in detail. The study demonstrated that the research activity in this field has been gaining importance. Numerous sensor technologies and analysis algorithms have been identified. Nonetheless, research gaps exist in topics such as optimized monitoring systems for industrial material extrusion facilities, inspection capabilities for additional quality characteristics, and standardization aspects. This literature review is the first to address process monitoring for material extrusion using a systematic and comprehensive approach.
Material extrusion, Fused deposition modeling, Process monitoring, Sensor technology, Research gaps
Software for an Automated Multidimensional Factory Layout Optimisation: Layout planning is a complex planning task in the context of factory planning, which up to now has usually needed to be carried out manually. Although many optimisation methods for the underlying problem have been developed in the past, they were only applicable to a small group of experts, mostly from universities. Therefore, an easy-touse software for layout planning was developed in a research project to provide companies with access to these optimisation methods.
Factory planning, facility layout planning, optimization, operations research, software
The machine learning based method for layout optimization of smallscale modular conveyor systems, which is developed within a research project at IPH – Institut für Integrierte Produktion Hannover gGmbH, provides SMEs a decision support, which enables them to execute complex layout planning independently. In addition, the machine learning method is intended to reduce the cost and time required for planning and to improve the quality of the solution compared to manual layout design.
Small-scale modular conveyors, conveyor systems, machine learning, artificial intelligence
Maturity-based Evaluation of Requirements for a Successful MES Implementation. The use of a Manufacturing Execution System (MES) can offer many advantages for companies, but the implementation often poses a great challenge. The determination of necessary requirements, their fulfilment by the company and their consideration in the implementation process are decisive for a successful implementation. In the following article, the development of a maturity-based method for the evaluation and improvement of the companyspecific fulfilment of the requirements of an MES implementation is presented.
Manufacturing Execution System, Maturity Model, Digitalization
The production of hybrid components involves a long process chain, which leads to high investment costs even before machining. To increase process safety and process quality during finishing, it is necessary to provide information about the semi-finished parts geometry for the machining process and to identify defect components at an early stage. This paper presents an investigation to predict variations in dimension and cavities inside the material during cross-wedge rolling of shafts based on measured tool pressure. First, the process is investigated with respect to the variation in diameter for three roll gaps and two materials. Subsequently, features are generated from the hydraulic pressures of the tools and multi-linear regression models are developed in order to determine the resulting diameters of the shaft shoulder. These models show bet-ter prediction accuracy than models based on meta-data about set roll gap and formed material. The features are additionally used to successfully monitor the process with regard to the Mannesmann effect. Finally, a sensor concept for a new cross-wedge rolling machine to improve the prediction of the workpiece geometry and a new approach for monitoring machining processes of workpieces with dimensional variations are presented for upcoming studies.
Cross-Wedge Rolling, Forming, hybrid, tailored forming
Warm forged components have better surface properties and higher dimensional accuracy than hot forged components. Diamond-like-carbon (DLC) coatings can be used as wear protection coatings, which are anti-adhesive and extremely hard (up to 3500 HV), to increase tool service life. In the first funding period of the research project at the IPH – Institut für Integrierte Produktion Hannover gGmbH and the Institute for Surface Technology (IOT) of the Technical University of Braunschweig in cooperation with the Fraunhofer Institute for Surface Engineering and Thin Films (IST), the influence of different coating types and process temperatures on tool wear was investigated. The result is, that DLC coatings can reduce tool wear in some cases significantly, but that their service life is strongly dependent on the temperature. Coating-integrated temperature measurement could not be realised at that point, due to adhesion challenges. During the second funding period, the effect of multilayer DLC coatings on tool wear was investigated. Also, an additional method of the temperature measurement on the engraving surface using thin film sensors was developed in order to correlate the local process temperature and local layer wear. In this work, the development of and the results gathered by the thin film temperature sensors are presented, which enable for more accurate temperature measurements than commonly used thermocouples. Their functionality and durability under high loads were investigated and showed to be promising.
DLC2, warm forging, forging, wear, forming
To be able to meet the challenges of globalization, the optimization of internal transport is becoming increasingly important. Due to the further development, drones are an innovative material handling technology. The use of drones can be cost-efficient, especially for time-critical transport tasks. However, drones are characterized by a very low payload and very high operating costs. Therefore drones are in some cases more economical than conventional means of transport, but they do not offer an universal solution for all internal transport tasks.
drones, intralogistics, transport, transport systems, economic efficiency
Forging can be used to produce components with excellent mechanical properties. However, conventional drop forging does not offer the possibility of introducing undercuts into a workpiece and creating complex geometries with one forging stroke.
forging, undercuts
Solid formed components are subject to ever higher load requirements while at the same time striving for resource efficiency.
ciency at the same time. An ultrafine-grained microstructure can improve the strength and ductility of the component. This makes it possible to design smaller and lighter components and to exploit lightweight construction potential. One possibility
process for producing an ultrafine-grained microstructure is cross wedge rolling.
Cross wedge rolling, Fine-grained structure, Lightweight construction
Automated guided vehicles are a crucial component for more efficient production systems in intralogistics, but they have weaknesses in human-machine interaction. Scientists at IPH are developing a gesture-based control system to make the interaction intuitive and increase its acceptance.
Driverless transport vehicles, guidance control, gesture-based control
