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Scope of the presented work is a detailed comparison of a macroscopic draping model with real fibre architecture on a complex non-crimp-fabric preform using a new robot-based optical measurement system. By means of a preliminary analytical process design approach, a preforming test centre is set up to manufacture dry non-crimp-fabric preforms. A variable blank holder setup is used to investigate the effect of different process parameters on the fibre architecture. The real fibre architecture of those preforms is captured by the optical measurement system, which generates a three-dimensional model containing information about the fibre orientation along the entire surface of the preform. The measured and calculated fiber orientations are then compared with the simulation results in a three-dimensional overlay file. The results show that the analytical approach is able to predict local hot spots with high shear angles on the preform. Macroscopic simulations show a higher sensitivity towards changes in blank holder pressure than reality and limit the approach to precisely predict fibre architecture parameters on complex geometries.

The rapidly developing market for high strength and high stiffness carbon fibre reinforced polymers (CFRP) among others demands for reliable damage evaluation methods at very high cycle fatigue loading (VHCF). Due to the anisotropic nature of continuous fibre reinforced composites, fatigue damage is initiated in various failure modes. In case of low cycle and high cycle fatigue loading they are well comparable with the failure modes known from static loading. For the analysis of the widely unknown damage behaviour of CFRP at VHCF-loading, specific test principals and a shaker based fatigue test stand are developed. The key aspects in the development are: • high frequency fatigue (f > 150 Hz) without significant warming of the specimen, • homogeneous stress distribution and minor through thickness stress gradients and • adjustable states of stress and mean stresses for the fatigue testing of specific failure modes. Using numerical and experimental investigations, a promising solution for the given problem has been found in form of a shaker based shearing force free bending test stand and a specifically produced specimen. The deformation measurement and specimen observation is performed by a combination of eddy current sensors and digital image processing. With this basis, reliable VHCF-fatigue experiments for CFRPs with and without nanoparticles are performed for the development and validation of damage initiation criteria.

The strain rate dependent in-plane and through-thickness deformation and failure behaviour of textile reinforced polypropylene is investigated. An efficient in-plane parameter identification method based on rheological models is presented. Additionally, dynamic tensile, compression and shear tests were performed with woven and knitted textile reinforced thermoplastic composite specimens. As a result, the experimental methodology as well as strain rate dependent stiffness and strength properties within a strain rate range of 10 −5 up to 10 3 1/s are presented. A phenomenological 3D material model based on the Cuntze failure criteria, accounting for strain rate dependency and damage evolution is implemented in Abaqus/Explicit. The user defined material model (VUMAT) is used for finite element (FE) studies of the crash and impact experiments. Exemplary numerical predictions are presented and compared.

The cross-industry trend towards efficient lightweight solutions continues unabatedly and leads to an increasing use of structural components made of fibre composites. At the same time, there is an increasing demand for the realization and integration of additional functions such as sensory properties. For the widespread application of intelligent lightweight components, manufacturing technologies suitable for series production are required. Fibre-reinforced polyurethane composites offer a great potential for the production of smart lightweight structures. A novel method based on the Long Fibre Injection (LFI) technology enables the integration of piezoceramic components and by their direct connection to suitable electrode structures the process immanent fabrication of sensory elements.

Z-pins have been shown to significantly improve delamination resistance and impact strength of carbon fibre reinforced (CFRP) composites. In this paper, an experimental investigation of the influence of different fatigue parameters (mean opening/sliding displacement, amplitude, frequency, number of cycles) on the through-thickness reinforcement (TTR) is presented. For mode I, it is shown that the degradation on pin behaviour during fatigue is mostly affected by the applied displacement amplitude. The degradation is primarily caused by surface wear. Due to the brittleness of the Z-pins, mode II fatigue does not have a significant effect for very small sliding displacements. Exceeding a critical displacement causes the pin to rupture within the very first cycles.

The aim of this study is the biomimetic optimisation of branched fibre-reinforced composites based on the detailed analysis of biological concept generators. The methods include analyses of the functional morphology and biomechanics of arborescent monocotyledons and columnar cacti as well as measurements and modelling of mechanical properties of biomimetic fibre-reinforced composites. The key results show evidence of notch stress reduction by optimised stem-branch-attachment morphology in monocotyledons and columnar cacti. It could be shown that some of these highly interesting properties can be transferred into biomimetic fibre-reinforced composites.

Impact induced elastic wave propagation in continuous fiber reinforced composite material is investigated with a special emphasis on the thickness direction. Due to wave reflection at the boundary delamination failure may occur. This phenomenon is assessed using analytical, experimental and numerical approaches and the results are compared. Especially the experimental procedure for wave propagation measurement and the determination of failure strengths at elevated strain rates is discussed. This work is carried out within the scope of EU H2020 funded EXTREME project (www.extreme-h2020.eu)

Magnesium alloys play an important role in the development of light metal matrix composites. Magnesium based metal matrix composites reinforced by particles and fibres (especially carbon fibres) are successfully applied in various fields of automotive and aircraft industry. Equally high potential in large-batch production regarding to relatively low price and high strength is expected from MMC with wires made of iron-based alloys. However, their application is hampered by the absence of intermetallic phase between iron and magnesium and low solubility of iron in magnesium. This paper makes a contribution to the investigation of the effect of steel wires surface preparation and of optimised production methods to improve the quality and type of adhesion with selected industrial magnesium alloys. The Fe/Mg-MMC specimens with steel wires reinforcement were manufactured by the help of advanced gas pressure infiltration method (GPI) in a graphite mould at Institute of Lightweight Engineering and Polymer Technology (ILK) of TU Dresden. For the examination of the obtained composites the computer tomography (CT), SEM microscopy with EDX, strength tests and fracture surface inspection has been used.

Cellulosebasierte Biopolymere mit Naturfaserverstärkung besitzen aufgrund ihrer Herstellung aus nachwachsenden Rohstoffen und ihrer regionalen Verfügbarkeit ein hohes Ressourceneffizienzpotenzial. Durch eine gezielte Kombination von kurzfaserverstärkten Granulaten und Halbzeugen mit Textilverstärkung ist ein Einsatz dieser Werkstoffgruppe auch in tragenden Leichtbaustrukturen möglich.

This paper concerned with modeling of the strain rate dependent material behavior of 3D-textile composites with simultaneous consideration of production and operational (e.g. pores or fatigue damage) defects. Therefore an additive model in the sense of continuum damage mechanics was introduced. For the model validation extensive experimental tests on glass non-crimp fabrics reinforced epoxy (GF-NCF/EP) composites are performed. The focus is put on the influence of production and fatigue related pre-damage under subsequent highly-dynamic tensile loading. The theoretical studies shows a good coincidence with the experimentally results

For the series production of adaptive fibre-reinforced thermoplastic structures, the development of process-adapted piezoceramic modules is gaining central importance. Thermoplastic-compatible piezoceramic modules are being developed which are suitable for a matrix-homogeneous adhesive-free integration of the modules in fibre-reinforced thermoplastic structures during a simultaneous welding process. Aiming at the continuous improvement of the novel module design and its manufacturing technology based on a hot-pressing technology, an adapted physical nonlinear simulation model was developed in order to analyze the material and process dependent function and consolidation behaviour. Special regard is given to residual stresses caused by different coefficients of thermal expansion of the component materials and their specific use to enhance the module performance.

Constantly rising demands on extremely stressed lightweight structures, particularly in traffic engineering as well as in machine building and plant engineering, increasingly require the use of continuous fibre-reinforced composite materials. Due to their selectively adaptable characteristics profiles, they are clearly superior to conventional monolithic materials. Composites with textile reinforcement offer the highest flexibility for adaptation to reinforcing structures in to complex loading conditions. This study shows that the gas pressure infiltration technique was successfully assessed for manufacture of carbon fibre reinforced aluminium metal composites (CF/Al-MMCs), consisting of unidirectional as well as bidirectional Ni-coated carbon fibres with different Al-alloy matrix systems. As wail as investigating of the deformation and failure behaviour of CF/Al-MMCs, their thermo-physical properties, were determined such as the coefficient of thermal expansion. Furthermore, fractographic analysis and closer microscopic inspections indicate they fail with a brittle fracture.

Against the background of an integration of piezoceramic modules into thermoplastic composite structures the development of thermoplastic-compatible piezoceramic modules (TPM) requires the consideration of the type of module-structure-connection and module position for an optimal strain transmission. While commercially available low profile transducers are applied predominantly by adhesive bonding, TPM with thermoplastic carrier films identical to the thermoplastic matrix of the composite structure offer the possibility for a material-homogeneous integration by a hot-pressing process. The aim of the presented work is to examine the influence of an adhesive layer as well as the comparison of adhesive bonding and module integration by a hot-pressing process. Therefore a common analytic model and the finite element method (FEM) is used. Particular regard is given to a maximum strain transmission between the functional module and the composite structure. For pure bending as well as for pure linear expansion the studies show the advantages of a material-homogeneous integration of function modules.

Detailed knowledge of the local fiber orientation and the local fiber volume content within composite parts provides an opportunity to predict the structural behavior more reliably. Utilizing forming simulation methods of dry or pre-impregnated fabrics allows for predicting the local fiber orientation. Additionally, during the forming process, so-called draping effects like waviness, gapping or shear-induced transverse compression change the local fiber volume content. To reproduce and investigate such draping effects, different manufacturing tools have been developed in this work. The tools are used to create fabric samples with pre-defined deformation states, representing the different draping effects. The samples are evaluated regarding the resulting fiber volume content. The experimental results are compared with the predictions of an analytical solution and of a numerical solution based on draping simulation results. Furthermore, the interaction of the draping effects at arbitrary strain states is discussed regarding the resulting fiber volume content.

In contrast to conventional manufacturing methods for sandwich structures, in this paper a foamable polyurethane system is used to impregnate textile layers and to create the sandwich foam core in one single process step. Given this simultaneous process, a high adaptability of the resulting mechanical properties can be achieved by varying the textile reinforcement of the sandwich top layers, the foam core density and the sandwich thickness, respectively. Within this paper, a design of experiment approach is implemented by using statistical analysis of variance (ANOVA) to investigate the influence of selected geometrical and material parameters on the resulting bending properties of these novel sandwich structures. A partial factorial design helps to identify the sensitivity of individual parameters and their interaction, as well as the correlation between sandwich morphology and bending performance. Based on the gained results, statistical models will help to identify parameters with statistical significance. Therefore, optimized sandwich structures according to stress-related requirements and geometrical constraints can be designed.

Due to their high specific stiffness and strength composites are ideally suited for applications in machine building, vehicle constructions, wind power technology and aviation. In the manufacture of composite structures voids are an unavoidable fact. Several non-destructive techniques are potentially able of detecting defects, but only the exact knowledge of the effects of defects on the mechanical properties allows the definition of thresholds for the purpose of quality management. Here, an experimental program for characterizing the effect of voids on the damage behaviour is presented. Flat specimens with glass fibre non-crimp fabric reinforcement and epoxy matrix (GF-NCF/EP) are produced using vacuum assisted resin transfer moulding. By means of a specific adjustment of the process parameters, test specimens with three different void contents are produced and compared. For detailed analysis of damage evolution in the vicinity of voids, in-situ computed tomography (in-situ CT) is used, for the volumetric visualization of the material during tensile loading.

The use of adaptive composite structures in series applications requires novel actuators and related manufacture processes capable for serial production. The paper shows latest research results with regard to the continuous development of novel thermoplastic-compatible piezoceramic modules (TPM). These modules are predestined for the material homogeneous actuator integration in fibre-reinforced thermoplastic composites by means of a welding process. The research focuses on numerical and experimental studies in order to design efficient modules capable for a continuous production process. Especially studies with regard to geometrical parameters and their influences on the actuator performance as well as studies with respect to the manufacture process are accomplished.

For a reliable structural design of security-relevant, high-dynamically loaded light weight structures, the knowledge of the strain-rate-dependent material and damage behaviour, material properties, and validated material models have to be provided. For this purpose, various material tests at different strain rates have been performed on composites with a novel 3D-reinforced glass-fibre multilayered flat-bed weft-knitted fabric reinforcement by using a servohydraulic high-speed testing unit in combination with specially adapted clamping de vices. The highly dynamic material tests served to develop adequate material models in the classical sense of continuum damage mechanics and to determine the associated model parameters.

Smart fiber-reinforced composites, such as long fiber or textile-reinforced polymers are often functionalized by integration of piezoelectric transducers to realize sensory and actuatory tasks like condition and structural heath monitoring, energy harvesting or active vibration damping. Each of these tasks is connected with specific requirements with regard to the electromechanical behavior of the composite structure. In this chapter, several qualitative and quantitative methods including nondestructive, optical, electrical, and mechanical testing for the characterization of smart fiber-reinforced composites are described. Beyond their functionality and electromechanical performance, structural integrity and quality assurance are focused. By example of case studies, characterization of long fiber-reinforced thermoset and textile-reinforced thermoplastic polymers with specific test setup and results are shown. Novel developments in the field of sensor and actuator development and manufacture as well as integration of these functional elements into fiber-reinforced composites are presented.

In contrast to common and classical joining technologies for composite/metal hybrid structures such as bonding and riveting, profile and contour joints offer a promising potential for novel lightweight hybrid structures. First and foremost, joining systems with a form closure function enable to pass very high loads into rod- and tube-shaped fibre reinforced structures and achieve high degrees of material utilization for the composite part. This paper demonstrates the theoretical and technological principals for a resource efficient design and production of highly loaded thermoplastic composite profile structures with integrated metallic load introduction elements and a multi scale form closure. The hybrid structures are produced in an integral blow moulding process in which a braided tape-preform is simultaneously consolidated and formed into the metallic load introduction element. These metallic load introduction elements are manufactured in a two-stage process of external and internal hydroforming, afte...

A significant proportion of the work effort for a whole engine analysis is spent for prep-processing tasks especially for component assemblies and complex structural components. With respect to the generation of a pure hexahedral mesh, the work effort increases due to the absence of an automatic method to generate high quality hexahedral meshes for an arbitrary geometry. In addition, the time-consuming hexahedral meshing process contains numerous, repetitive tasks for large and complex assemblies due to similar and identical components. In this work a modular strategy for hexahedral meshing of large and complex assemblies was explored with the aim to reduce and to simplify the development process due to a prospective semi-automation of time-consuming routines. The procedure bases on an initial identification and classification of each component of the whole assembly regarding e.g. overall meshing complexity. Meshing relevant parameters were identified for geometry preparation and hexahedral meshing itself. Furthermore, for semi-automation the software package NX (Siemens NX Software), in particular the incorporated automation tool Product Template Studio (PTS) was investigated which enables an automated re-meshing of the geometry model in case of design changes.

To develop design rules for dynamically loaded composite structures, extensive static and cyclic tension/compression-torsion tests were carried out on carbon-fibre-reinforced composites, in which especially the important influence of multiaxial loading conditions on their fatigue behaviour was investigated. Physically based failure criteria for static loadings are modified for multiaxial cyclic loadings, and a good agreement with experiments is achieved.

Summary — This paper gives an overview of recent activities in the production of natural fiber-reinforced polyurethane (PUR) composites. Extensive research is being conducted to develop marketable solutions for the production of bio-based plastics. In composite applications, natural fibers can be used as a substitute for synthetic fibers and help to make a significant contribution towards ecological and efficient lightweight components. In addition, an outlook on current developments in Long Fiber Injection (LFI) processing for the application of natural fiber-reinforced polyurethane composites, specifically in electric vehicles is given.

The high specific strength and stiffness of composite materials, as well as the possibility of creating a load-adapted property profile of them are ideally suited for the design of high-speed lightweight rotors. With respect to a load-adapted reinforcement structure of composite rotors, the rotor geometry has a significant influence on the optimum fibre orientation. In the case of conical rotors—the structural behaviour is strongly influenced by centrifugally induced bending effects in the rotor structure, which cause complex three-dimensional stress states in combination with the ordinary tangential and radial stresses. For analysis of the resulting complex stress states, an analytical method has been developed and verified numerically as well as experimentally. The novel method presented here is the basis for a realistic failure analysis and, in particular, serves as an efficient tool for extensive parameter studies and optimizations within the design process.

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 established manufacturing processes (e.g., filament winding) often inhibit the use of CFRP components in a high-volume car series. In this paper, a novel composite driveshaft system based on a profiled CFRP tube is presented. This system is designed to be produced by a continuous pultrusion process to achieve a significant reduction of the manufacturing costs. A cost assessment study was conducted to quantify the benefit of the developed continuous manufacturing process. In comparison with the state-of-the-art filament winding process, a cost reduction of 36% for the composite shaft body can be obtained. Moreover, the proposed fiber layup processes – braiding and continuous winding – offer the potential to manipulate the reinforcement architecture to maximize material utilization without reducing the manufacturing efficiency. This potential is investigated and validated by experimental tests. A difference in the load bearing capacity of more than 100% between different reinforcing architectures is shown.

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.

Increasing economic, political and ecological pressure leads to steadily rising percentage of modern processing and manufacturing processes for fibre reinforced polymers in industrial batch production. Component weights beneath a level achievable by classic construction materials, which lead to a reduced energy and cost balance during product lifetime, justify the higher fabrication costs. However, complex quality control and failure prediction slow down the substitution by composite materials. High-resolution fibre-optic sensors (FOS), due their low diameter, high measuring point density and simple handling, show a high applicability potential for an automated sensor-integration in manufacturing processes, and therefore the online monitoring of composite products manufactured in industrial scale. Integrated sensors can be used to monitor manufacturing processes, part tests as well as the component structure during product life cycle, which simplifies allows quality control during production and the optimization of single manufacturing processes.[1;2] Furthermore, detailed failure analyses lead to a enhanced understanding of failure processes appearing in composite materials. This leads to a lower wastrel number and products of a higher value and longer product life cycle, whereby costs, material and energy are saved. This work shows an automation approach for FOS-integration in the braiding process. For that purpose a braiding wheel has been supplemented with an appliance for automatic sensor application, which has been used to manufacture preforms of high-pressure composite vessels with FOS-networks integrated between the fibre layers. All following manufacturing processes (vacuum infiltration, curing) and component tests (quasi-static pressure test, programmed delamination) were monitored with the help of the integrated sensor networks. Keywords: SHM, high-pressure composite vessel, braiding, automated sensor integration, pressure test, quality control, optic-fibre sensors, Rayleigh, Luna Technologies

During the manufacturing process of multilayered fiber-reinforced composites with variable fiber orientations, residual stresses build up in these composites due to the directional expansion of single unidirectionally reinforced layers. Depending on the laminate lay-up, the inhomogeneous residual stresses, which are caused by thermal effects, moisture absorption, and chemical shrinkage, can lead to large multistable out-of-plane deformations. Instead of avoiding these curvatures, they can be advantageously used for technical applications following the near-net-shape technology. In order to adjust the deformations to the technical requirements, genetic algorithms in combination with a nonlinear calculation method have been developed, which can purposefully adapt the laminate lay-up depending on the loading and process parameters.

A novel approach to the manufacture of adaptive composite structures with integrated piezoelectric modules focusses on combining the previously separate production steps – production of the piezoceramic transducer, composite fabrication and integration of the transducers – into an efficient single-stage process. Based on the long fibre injection (LFI) technology, a novel multi fibre injection (MFI) method is developed. By integrating piezoceramic components like short fibres or pearls and suitable electrode structures into the composite, novel piezoelectric functional elements are created and embedded during the structure's manufacturing process. For the functionalisation of these elements, mainly to provide sensory properties, poling of the piezoceramic components during or after the production process is required. Based on initial simulations of electric field strength, poling process and resulting small signal properties, conclusions for an adapted poling strategy of these novel sensor modules are elaborated.

In this work, we evaluate the pyroelectric response of PZT plates and rods embedded in epoxy resin, low temperature cofired ceramics and polyamide by measuring the pyroelectric current spectrum originated by temperature oscillations generated by illuminating the sample surface with a square-wave-modulated laser beam. Transfer functions H(iω) describing amplitude attenuation and phase lag at each modulation frequency were analyzed by means of a Nyquist plot. Changes in pyroelectric current amplitude and phase produced by small periodic perturbations around the equilibrium are related to thermal losses governing the return of the system to the equilibrium. This allows evaluating the thermal contact of PZT with the embedding material.

Active composite structures based on thermoplastic matrix systems are highly suited to applications in lightweight structures ready for series production. The integration of additional functional components such as material-embedded piezoceramic actuators and sensors and an electronic network facilitates the targeted control and manipulation of structural behaviour. The current delay in the widespread application of such adaptive structures is primarily attributable to a lack of appropriate manufacturing technologies. It is against this backdrop that this paper contributes to the development of a novel manufacturing process chain characterized by robustness and efficiency and based on hot-pressing techniques tailored to specific materials and actuators. Special consideration is given to detailed process chain modelling and analysis focusing on interactions between technical and technological aspects. The development of a continuous process chain by means of the analysis of parameter influences is described. In conclusion, the use of parameter manipulation to successfully realize a unique manufacturing line designed for the high-volume production of adaptive thermoplastic composite structures is demonstrated.

One challenge in micrometrology is to measure precisely the shape of fast moved objects with high temporal resolution. Deformation measurements of lightweight composite materials are of importance to guarantee its robustness e.g. against impacts. In a high-speed rotor test rig their elastic and plastic deformations due to centrifugal forces can be evaluated. Non-contact inspection techniques with micron resolution under vacuum conditions are necessary. For the first time, we present high-speed deformation measurements of a cylindrical rotor by a non-incremental laser Doppler distance sensor system using fiber and diffractive optics. Besides the determination of the radial enlargement also wobbling of the rotor was monitored.

Fiber-reinforced composites are constantly optimized to meet high standards such as lightweight, a good load-bearing capacity and the ability to withstand high torsion and bending forces and moments. These mechanical loads are especially high in nodal elements and manufacturing of ramifications with an optimized force flow is one of the major challenges in many areas of fiber-reinforced composite technology, e.g. branching points of framework constructions in building industry, aerospace, ramified vein prostheses in medical technology or the connecting nodes of axel carriers. A biomimetic Top-Down-Process’ is currently applied to address this problem via an adaptation of innovative manufacturing techniques and the implementation of novel bio-inspired mechanically optimized fiber-arrangements and fiber-matrix-transitions. Hierarchically structured plant ramifications serve as concept generators for innovative, biomimetic branched fiber-reinforced composites. Promising biological role models are tree-like monocotyledons, including Dracaena and Freycinetia species. The ramifications in these plants show a pronounced fiber matrix structure and a special hierarchical stem organization, which markedly differs from that of other woody plants by consisting of isolated fiber-bundles running in a partially lignified ground tissue matrix. Our preliminary morphological and biomechanical analyses confirm that these lightweight ramifications possess mechanical properties interesting for a transfer into bio-inspired technical applications, such as a benign fracture behavior and good dynamic energy absorption. The results from the biological role models are currently transferred in the development of concepts for producing demonstrators and first prototypes in lab-bench scale of biomimetic branched fiber-reinforced composites.

The use of so-called compliant elements with specifically adjustable compliances offers the possibility to transmit motions just by structural deformations. This paper makes a contribution to the efficient cyclic test of textile-reinforced compliant structures by developing a novel kinematictest stand realizing pure bending.

To achieve the aim of building a car to customer order within 5 days, an innovative modular concept car was conceived that supported the planned costeffective built-to-order proposition and stockless production. In a multi-stage design process the automotive body shell, outer panels and selective outer structures have been developed to fit over the modular body frame, offering numerous advantages. The project had a twin aim of meeting not only the technical requirements, which included not only modularity, safety, low weight and a panoramic view, but also the emotional design aspects, including looking “sporty” and “agile”. The appearance of the car body shell for the ModCar is of great importance if it is to be commercially viable and achieve success in the marketplace. Developments in lightweight materials and process technologies enabled the development of advanced function-integrated lightweight vehicle modules for series manufacture. The ModCar fulfils the criteria regarding passenger protection with respect to the Euro-NCAP standards. In addition, simulations show that the essential bending stiffness has been achieved. An optimised lightweight door module consisting of novel materials demonstrates good overall performance with regard to static load and crash behaviour testing. As such, the ModCar demonstrates that the novel concepts employed may be used to successfully produce a vehicle that is saleable in the European market.

The aim of this work was the development of sandwich structures formed by embedding magnetorheological elastomers (MRE) between constrained layers of carbon fibre–reinforced plastic (CFRP) laminates. The MREs were obtained by mechanical stirring of a reactive mixture of substrates with carbonyl-iron particles, followed by orienting the particles into chains under an external magnetic field. Samples with particle volume fractions of 11.5% and 33% were examined. The CFRP/MRE sandwich structures were obtained by compressing MREs samples between two CFRP laminates composed. The used A.S.SET resin was in powder form and the curing process was carried out during pressing with MRE. The microstructure of the manufactured sandwich beams was inspected using SEM. Moreover, the rheological and damping properties of the examined materials with and without a magnetic field were experimentally investigated. In addition, the free vibration responses of the adaptive three-layered MR beams were studied at different fixed magnetic field levels. The free vibration tests revealed that an applied non-homogeneous magnetic field causes a shift in natural frequency values and a reduction in the vibration amplitudes of the CFRP/MRE adaptive beams. The reduction in vibration amplitude was attributed mainly to the stiffening effect of the MRE core and only a minor contribution was made by the enhanced damping capacity, which was evidenced by the variation in damping ratio values.

The use of integrated structural health monitoring systems for critical composite parts, such as wind turbine blades, fuselage and wing parts, is an promising approach to guarantee a safe and efficient operational lifetime of such components. Therefore, the integration of thick functional components like sensors, actuators and electronic components is often necessary. An optimal integration of such components should be ensured without material imperfections in the composite structure, i.e. voids and resin rich areas, and failure of the functional components. In this paper, first investigations were undertaken for a basic understanding of the mechanical performance of a fibre reinforced plastic component with integrated functional elements. The influence of different materials and treatment methods for the encapsulation of electronic components was experimentally investigated under static and dynamic loading tests. By means of a parametric finite element model, the effects of an encapsulation and various parameters such as the shape and orientation of the electronic components were examined. Several encapsulation variants were investigated in order to minimise the chance of failure initiations. Based both on experimental and numerical results, a preferred composite integration concept was selected for an electronic board and some first recommendations for an optimal integration were derived.

In contrast to common joining technologies for composite-metal hybrid structures such as bonding and riveting, contour joints offer promising potential in terms of manufacturing efficiency and mechanical performance. For composite structures, joining systems with positive locking elements enable to pass high loads and are capable to achieve high degrees of material utilisation. To enhance the performance of hybrids, a multi-scale structuring approach is sought. Aiming at high rate production, especially in automotive industry, an intrinsic manufacturing approach whereat the composite part is joined to the metallic part during its consolidation process has been developed. This paper demonstrates the intrinsic manufacturing principles of continuous fibre-reinforced thermoplastic hollow profiles with multi-scale-structured load introduction and mainly focuses on the development of a fibre appropriate design. Based on a design of experiment approach, numerical parameter studies for the optimisation of macro contour have been carried out to create a general design guideline.

The use of active composite structures in high-volume applications requires novel robust manufacturing processes as well as specially adapted functional modules. The paper presents actual research results with regard to the process-immanent polarization of novel thermoplastic-compatible piezoceramic modules (TPM) during the consolidation process of active fibre-reinforced thermoplastic composite structures. In particular the influence of varying manufacture process parameters of a hot-press process on the polarization behaviour is investigated. The main principal objective is the purposeful utilization of process parameters for polarization support.