Showing papers by "Maik Gude published in 2015"
TL;DR: In this paper, a new joining technology to produce hybrid structures with continuous fibre reinforced thermoplastics and metallic components is introduced, adapting the concept of classical clinching for thermoplastic composites.
40 citations
TL;DR: In this paper, an experimental program for characterizing the effect of voids on composite materials behavior is presented, where glass fibre non-crimp fabric reinforced epoxy composites were produced using vacuum assistant resin transfer molding.
Abstract: The manufacture of composite structures is inevitably linked to the formation of voids. Several non-destructive techniques are potentially able of detecting defects, but just the exact knowledge of the effects of defects on the mechanical properties allows the definition of thresholds for the purpose of quality management. In this paper an experimental program for characterizing the effect of voids on the composite materials behaviour is presented. Therefore glass fibre non-crimp fabric reinforced epoxy composites were produced using vacuum assistant resin transfer moulding. For obtaining various void contents specially modified process parameters were used. Nominally defect free specimens are compared with flawed specimens. Tensile testing at different loading speeds and fatigue tests in tension-compression loading are performed.
27 citations
TL;DR: In this paper, the V-notched rail shear test (VNRS) was modified with the main focus of lines of force as well as precise and economic specimen clamping.
23 citations
TL;DR: The high specific strength and stiffness characteristics of composite materials such as carbon fiber-reinforced plastic (CFRP) allow a significant weight reduction of the structural machine components such as automobile driveshafts.
Abstract: The high specific strength and stiffness characteristics of composite materials such as carbon fiber-reinforced plastic (CFRP) allow a significant weight reduction of the structural machine components such as automobile driveshafts. But high material cost and rather low productivity of the...
14 citations
TL;DR: In this paper, an optical measurement system is introduced to measure the rotor deformation with a measurement rate of 1.6 kHz with an 7μm error independent on the rotational speed.
10 citations
TL;DR: In this paper, a spray coat method based on the long fibre injection (LFI) process is developed, which allows the process-integrated manufacturing and embedding of novel piezoelectric sensor modules into fibre-reinforced polyurethane composite structures.
Abstract: Due to an increasing use of composite materials in various applications and related open questions concerning structural health monitoring and damage detection, the realisation of function integrating lightweight structures with sensory properties is subject of numerous research activities. Main objective is the transfer of already in laboratory and prototype scale established methods for the integration of sensory elements on serial applications. Here, combining the previously separated processing steps sensor manufacturing, component manufacturing and sensor integration can help to make a significant step forwards. Therefore, as part of the activities in the Collaborative Research Centre/Transregio (CRC/TR) 39, a highly productive spray coat method based on the long fibre injection (LFI) process is developed, which allows the process-integrated manufacturing and embedding of novel piezoelectric sensor modules into fibre-reinforced polyurethane composite structures.Based on studies on the technological implementation of the newly developed process, theoretical and experimental studies for contacting and polarisation of the novel sensor elements are presented. In addition, the characterisation of the adhesion properties of thermoplastic films on the used fibre-reinforced polyurethane composites is part of the presented research to evaluate the possibility of integrating thermoplastic-compatible piezo modules for actuator applications.
6 citations
01 Jan 2015
TL;DR: In this article, a fracture mode-related modeling approach under consideration of embedding effects is presented for the simulation of textile-reinforced composites, illustrated by the example of 3D glass fiber reinforced epoxy (GF-MLG/EP).
Abstract: The static as well as the fatigue degradation and failure behaviour of fibre-reinforced composites is characterised by the presence of distinctive failure modes. On the scale of the unidirectional or textile-reinforced layer, even uniaxial macroscopic loads result in multiaxial states of stress. This mesoscopic stress state can be used for the modelling of damage and material degradation related to typical failure modes. The modelling and test strategy pursued, derived from a fracture mode-related modelling approach under consideration of embedding effects, and the applicability of the presented approach for the simulation of textile-reinforced composites, are illustrated by the example of 3D glass fibre-reinforced epoxy (GF-MLG/EP). Static as well as cyclic tests under superposed tension/compression–torque loading are performed using tubular specimens. Besides the analysis of the stiffness and strength degradation, the failure mode-specific crack growth of selected specimens has been recorded. By correlation of the visible damage and the stiffness degradation, the developed mathematical descriptions of the failure mode-specific damage growth are validated.
1 citations
01 Jan 2015
TL;DR: In this article, the yarn impregnation of various composites is quantified with the help of grey value analysis of micrographs to evaluate the influence of the textile parameter and the fibre type.
Abstract: Injection methods for the manufacture of fibre-reinforced plastics are performed using vacuum assistance and/or the application of pressure such as in presses or autoclaves to impregnate textile preforms. Within this article, the impregnation of textile preforms using a polyurethane spray coat method is examined. In contrast to conventional manufacture methods, the impregnation is performed using the expansion pressure of a polyurethane foam matrix. Further, the yarn impregnation of various composites is quantified with the help of grey value analysis of micrographs to evaluate the influence of the textile parameter and the fibre type.
1 citations
TL;DR: In this article, the authors deal with the understanding and performance capabilities of actuarical hollow fiber-reinforced composite tubular segments, where the selective excitation and manipulation of the vibration behavior of such rotationally symmetric structures serves for generation of wave effects with radial translational characteristic.
Abstract: Regarding the economical use of fiber-reinforced plastics (FRP) as a construction material for structural components whose additional value caused not only in their high specific mechanical properties. Due to the layerwise structure definition of continuous fiber reinforced composites the corresponding production technologies offers a high potential for integration of additional functional elements. Past efforts to the integration of functions in fiber-reinforced composites usual provide in front of a passive use of the piezoelectric effect (eg. structural-health monitoring). Through efficient and structurally defined using of piezoceramic actuators, the planar structure topology of cylindrical hollow FRP profiles can be actively influenced. Based on experimental studies on the definition of basic concepts for the integration of thermoplastic compatible piezoceramic modules (TPM) in fiber composite tubular segments, this paper deals with the understanding and performance capabilities of such actuarical hollow frp structures. The selective excitation and manipulation of the vibration behavior of such rotationally symmetric structures serves for generation of wave effects with radial translational characteristic. The performed experimental studies on the structural behavior of active piezo integral pipe segments are abstracted and compared by means of numerical simulations using multi-physical elements.