DEVELOPMENT OF THE DIRECT ROVING PLACEMENT TECHNOLOGY (DRP)

The Direct Roving Placement (DRP) technology is in development at the Institute of Composite Structures and Adaptive Systems of the German Aerospace Center (DLR). A fully functional robotic unit that is able to produce dry glass or carbon fiber preforms has been set up at the Center for Lightweight Production Technology (ZLP) in Stade. All relevant process and material parameters that have an influence on the mechanical properties of parts being built with the DRP technology, are investigated. The main advantages of this new fiber placement technology are low material costs and high productivity. The core of the technology, the end-effector, is able to process raw carbon fibers as well as glass fiber rovings. The biggest difference compared to other placement technologies is the integrated online binder application system. The binder system is used to keep the fiber rovings fixed in position, after they have been applied onto a three-dimensional tooling surface. In addition, the online application of a binder provides multiple options of individually tuning the mechanical properties of the preform or the final part

Direct Roving Placement

In this paper the Direct Roving Placement technology (DRP) is presented as a new technology for the automated production of wind energy rotor blades. The DRP-technology is one part within the development of a complete process chain for the production of prototype rotor blades for research purposes. Primary objective of the DRP-technology is the reduction of the overall manufacturing costs, by lowering the material costs. This can be achived by the direct processing of the raw fiber material, eliminating the fabric manufacturing processes. In addition to that, the aim of the research activities is to reach high production rates and improve overall manufacturing quality with an automated high volume direct fiber layup process

Automatisierte Fertigung von Rotorblättern für Windenergieanlagen

Der Erfolg einer Automatisierungslösung für die Faserablage wird vor allem daran gemessen, ob es gelingt, die Fertigungskosten des Rotorblatts sowie dessen Fertigungszeit zu senken. Die Hürden hierfür sind hoch. Bei den aktuellen Blattarchitekturen und Bauweisen müssen nicht nur Fasern abgelegt, sondern auch Stützstoffe in den Bereichen des Blatts mit Sandwichhäuten platziert werden. Dieser Beitrag des DLR beschreibt, dass eine erfolgreiche Automatisierung für die Faserablage nicht nur die Fertigungskosten reduzieren muss, sondern auch die Materialeinzelkosten

REDUCING MANUFACTURING COSTS BY DIRECT ROVING PLACEMENT (DRP)

The Direct Roving Placement technology (DRP) is presented as an upcoming technology for the automated production of dry fibre composite preforms. Primary objective of the DRP technology is the reduction of the overall manufacturing costs, mainly by lowering the material costs. This can be achieved by directly processing raw fibre material combined with an online application of appropriate binders for the fibre fixation. This makes preceding fabric manufacturing processes as well as material wasting cutting processes unnecessary. One of the key technologies for a successful introduction of DRP technologies, a focus of this paper and the ongoing research, is the binder application, the binders themselves and their influence on the process and the material. Furthermore, the research activities are aiming for high production rates and improved overall manufacturing quality with an automated high volume direct fibre layup process

Data from: Cortical thickness, surface area and subcortical volume differentially contribute to cognitive heterogeneity in Parkinson's disease

Parkinson's disease (PD) is often associated with cognitive deficits, although their severity varies considerably between patients. Recently, we used voxel-based morphometry (VBM) to show that individual differences in gray matter (GM) volume relate to cognitive heterogeneity in PD. VBM does, however, not differentiate between cortical thickness (CTh) and surface area (SA), which might be independently affected in PD. We therefore re-analyzed our cohort using the surface-based method FreeSurfer, and investigated (i) CTh, SA, and (sub)cortical GM volume differences between 93 PD patients and 45 matched controls, and (ii) the relation between these structural measures and cognitive performance on six neuropsychological tasks within the PD group. We found cortical thinning in PD patients in the left pericalcarine gyrus, extending to cuneus, precuneus and lingual areas and left inferior parietal cortex, bilateral rostral middle frontal cortex, and right cuneus, and increased cortical surface area in the left pars triangularis. Within the PD group, we found negative correlations between (i) CTh of occipital areas and performance on a verbal memory task, (ii) SA and volume of the frontal cortex and visuospatial memory performance, and, (iii) volume of the right thalamus and scores on two verbal fluency tasks. Our primary findings illustrate that i) CTh and SA are differentially affected in PD, and ii) VBM and FreeSurfer yield non-overlapping results in an identical dataset. We argue that this discrepancy is due to technical differences and the subtlety of the PD-related structural changes

Raw_data_Gerrits_Dryad

See the Dryad_ReadMe_Gerrits word file

Cortical Thickness, Surface Area and Subcortical Volume Differentially Contribute to Cognitive Heterogeneity in Parkinson's Disease.

Parkinson's disease (PD) is often associated with cognitive deficits, although their severity varies considerably between patients. Recently, we used voxel-based morphometry (VBM) to show that individual differences in gray matter (GM) volume relate to cognitive heterogeneity in PD. VBM does, however, not differentiate between cortical thickness (CTh) and surface area (SA), which might be independently affected in PD. We therefore re-analyzed our cohort using the surface-based method FreeSurfer, and investigated (i) CTh, SA, and (sub)cortical GM volume differences between 93 PD patients and 45 matched controls, and (ii) the relation between these structural measures and cognitive performance on six neuropsychological tasks within the PD group. We found cortical thinning in PD patients in the left pericalcarine gyrus, extending to cuneus, precuneus and lingual areas and left inferior parietal cortex, bilateral rostral middle frontal cortex, and right cuneus, and increased cortical surface area in the left pars triangularis. Within the PD group, we found negative correlations between (i) CTh of occipital areas and performance on a verbal memory task, (ii) SA and volume of the frontal cortex and visuospatial memory performance, and, (iii) volume of the right thalamus and scores on two verbal fluency tasks. Our primary findings illustrate that i) CTh and SA are differentially affected in PD, and ii) VBM and FreeSurfer yield non-overlapping results in an identical dataset. We argue that this discrepancy is due to technical differences and the subtlety of the PD-related structural changes