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
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