Papers by Keyword: Inserts

Abstract: Resin Transfer Molding (RTM) enables an intrinsic manufacturing of fiber reinforced composite parts containing integrated metallic inserts. The inserts are embedded into the fiber layers in the preforming stage of the process and therefore influence the following mold filling. The fiber structure around the embedded insert is strongly influenced by the insert resulting in high local variations of fiber volume fraction which changes the local permeability. This leads to an inhomogenic flow front and can even result in dry spots of the cured part. To predict the formation of air bubbles, a two-phase mold filling simulation is used under consideration of local fiber volume fraction. Local fiber structure is determined using CT-scans of manufactured parts with different orientations of the insert in relation to the preform and to the filling direction. The mold filling simulations allow the evaluation of different filling strategies and show a strong influence of the insert on the local flow front propagation.

Abstract: This paper shows the results of solving a 3D problem to define types of structures and tensions which can appear during the butt contact welding process of dissimilar steels through low carbon steel inserts. The finite element method to calculate welded structures was used. The thickness of inserts was the main variable parameter. According to the results of numerical simulation using inserts can increase the reliability of welded joints between pearlitic high-carbon steel and austenitic chromium-nickel steel. The best result was obtained by using an insert with a thickness less than 20 mm. Structural studies of the welded joints between high-carbon steel and chromium-nickel steel through low-carbon inserts confirm the results of mathematical modeling.

Abstract: The use of fiber-reinforced-plastics (FRP) contributes to an efficient implementation of lightweight design due to their outstanding specific mechanical properties. The RTM process offers great design freedom and allows the integration of functional elements during manufacturing. Embedded metal elements, so-called inserts, can be used to deal with the load transfer to structural parts. These elements have distinctive characteristics in comparison to other joining technologies. For example, detachable connections can be established with the help of inserts. Due to the fiber continuity not being interrupted and, subsequently, the FRP parts not having to be drilled, there is no local bearing stress. This paper aims at the characterization of metal inserts in FRP parts. The parts are manufactured using the RTM process with a specially adapted RTM mold with exchangeable cartridges for different insert geometries. The inserts are made of metal sheets with welded bushings and are embedded during preforming. The cured FRP specimens are tested under different load conditions to evaluate their suitability for various fields of application. Furthermore, the diameter and thickness of the metal sheet of the insert as well as the thickness of the FRP are varied to identify their influence on the failure behavior and load capacity under tensile loads.

Abstract: The paper presents a situation of working in network in order to design or improve a new product. To implement theoretical models and to validate a working algorithm into a virtual research, there was proposed a specific theme from drilling and chamfering tool. The facilities offered by the research centers – database, software - led to rapid selection and configuration solutions, demonstrating achieving research productivity growth and a substantial reduction of times redesign.

Abstract: This paper presents results of the investigation of Si₃N₄ ceramic inserts with CVD coatings in turning grey cast iron. The high effectiveness of Si₃N₄ ceramic inserts with multi-layered coating in the finish turning of the grey irons was shown. It was established that at the heart of the wear mechanism of coated Si₃N₄ ceramic inserts there is a chain of relations cutting conditions loading fracture of coating сhipping of ceramic surface layer failure of tools. One of the important features of wear mechanism of these tools is the operational defects formed at the coating substrate interface.