• Title of article

    Multi-jet electrospinning systems can be designed to increase both productivity and cover area for large-scale nanofibre production. In this work several multi-jet electrospinning setups were tested. A solution of 7 wt% PEO was electrospun varying the num

  • Author/Authors

    Jari R?m?، نويسنده , , Veli-Tapani Kuokkala، نويسنده , , Taina Vuoristo، نويسنده ,

  • Issue Information
    روزنامه با شماره پیاپی سال 2009
  • Pages
    9
  • From page
    5186
  • To page
    5194
  • Abstract
    In the cold heading process of metals, strain rates in complex parts can vary considerably and locally reach very high values. Therefore, when considering the materialʹs deformation behavior, both the transient hardening at high strain rates as well as softening due to adiabatic heating should be accounted for. In this work, a purely phenomenological model based on experiments performed at strain rates in the range of 10−3–104 s−1 at temperatures extending from −150 to 800 °C was devised and used in finite element simulations of the cold heading process. The model separates yielding, including both the upper and lower yield point, from strain hardening, which typically depend on strain rate in a different way due to the adiabatic thermal softening effects at higher strains. The simulation results show good agreement with the high strain rate cold heading results obtained using a direct impact Hopkinson split bar technique.
  • Keywords
    Cold heading , Hopkinson split bar , Numerical simulation
  • Journal title
    Journal of Materials Processing Technology
  • Serial Year
    2009
  • Journal title
    Journal of Materials Processing Technology
  • Record number

    1183620