Settings

Now showing1 - 8 of 8
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: with files ,
    Analysis and Modeling of Heat Flux into the Tool in Abrasive Circular Cutting of Unidirectional CFRP
    (Elsevier, 2017)
    Hintze, Wolfgang
    ;
    Klingelhöller, Christian
    For edge trimming of slightly curved thin walled CFRP parts dry circular cutting is a promising alternative. However, a high fraction of the cutting energy is converted into heat. The study focuses on the determination of the amount of heat dissipated by the tool in circular cutting of unidirectional CFRP with epoxy matrix. An inverse heat conduction model is developed and solved for a set of temperature profiles measured on the tool surface with an infrared camera. It was found, how the heat dissipation by the diamond abrasive cut-off wheel is affected by fiber orientation, cutting speed, feed velocity and immersion depth of the wheel. The projected cutting area normal to the fiber direction turned out to be crucial for heat dissipation. The results of numerical simulations and experiments indicate, that tool temperatures in dry circular cutting do not exceed temperature limits of CFRP present in dry end milling. The developed heat flux model allows for optimization of dry CFRP abrasive circular cutting processes. It forms a module for future workpiece temperature assessment and thermo-mechanical process simulation.
    Publicationtype: Journal Article
    Scopus© Citations 8  388  461
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      13
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      12
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      4
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
      19
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: with files ,
    Constant depth scoring of fibre reinforced plastic structures to prevent delamination
    (Elsevier, 2014-06)
    Geis, Tobias
    ;
    Klingelhöller, Christian
    ;
    Hintze, Wolfgang
    Scoring of the outer layers of a workpiece with small engagement (ae) using circular saws is a well known method to avoid unwanted delamination of these layers, such as coatings of wooden particle boards. In edge milling fibre reinforced plastics (FRP), delamination also occurs in the top or bottom layer of the component and requires time intensive rework or scrapping of material. A combined process of scoring and milling is presented in this paper as a means to avoid delamination during machining of FRP structures such as aircraft carbon FRP parts. For the scoring process a diamond electroplated circular wheel is used. To guarantee a constant width of the scored slot, a constant depth of engagement is needed due to the shape of the grinding wheel. Therefore the profile of the scoring path on the workpiece surface is measured with respect to the machine coordinate system to correct a variation in the workpiece thickness and to compensate for uneven clamping. Next, the workpiece is scored with constant depth of engagement (ae,s < 0.5 mm) and a high feed velocity of up to 16 m/min. Subsequently, the scored component is machined with a conventional polycrystalline diamond (PCD) milling tool. From experiments it is proven that a delamination-free edge is achievable even with a worn tool (cutting edge radius rn > 50 μm) at an increased feed velocity (vf,m = 4.5 m/min). Without scoring, flawed workpiece edges have been obtained with cutting edge radii beyond rn > 23 μm (progressive uniform wear stage) and a feed velocity of vf,m = 1.5 m/min. Hence, high performance cutting (HPC) edge milling of composites may be realized by an initial scoring step to fulfil quality requirements of the machined edges and simultaneously increase the tool life of the milling tool.
    Publicationtype: Journal Article
    Scopus© Citations 11  352  262
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    Curved sawing of thin lightweight components
    (Springer, 2014)
    Hintze, Wolfgang
    ;
    Klingelhöller, Christian
    ;
    Langhof, O.
    Increasing application of carbon fibre reinforced plastic (CFRP) in lightweight constructions in aerospace, automotive and other industries requires highperformance cutting processes for edge trimming of thin shell structures. As an alternative to conventional processes, e.g. milling, a rigid abrasive circular saw blade is introduced. The limitation of cutting only almost-straight contours with circular saw blades is overcome by a novel tool geometry and process kinematic that allows curve cutting with radius R\500 mm on thin plane material (thickness t\10 mm). The kinematic for cutting almost arbitrarily shaped outlines with a circular tool on a five-axis machine is described and proven by cutting a reference component. Besides high operating efficiency because of high feed rate the process features sound edge quality without noteworthy delamination of the outer layers, which is shown in pilot tests on CFRP with unidirectional top layers.
    Publicationtype: Review Article
      8
  • Some of the metrics are blocked by your 
    consent settings
    Item type:Publication, Access status: without files ,
    Efficient and reliable grinding of landing gear parts
    (2013)
    Hintze, Wolfgang
    ;
    Hartung, F.
    ;
    Kawala, D.
    ;
    Klingelhöller, Christian
    ;
    Olesch, M.
    Publicationtype: Conference Paper
      3