Title :
Magnetic Repulsive Forces on ArmatureContacts
Author :
Merrill, Robert ; Stefani, Francis ; Watt, Trevor
Author_Institution :
Inst. for Adv. Technol., Univ. of Texas, Austin, TX
Abstract :
Transition to arcing contact in solid-armature railguns has been linked to several mechanisms. Recent work suggests magnetic blowoff forces arising from perimeter erosion as a possible significant mechanism. Three-dimensional finite-element (FE) models were constructed to analyze the repulsive contact forces resulting from perimeter erosion. Results show that magnetic blowoff occurs only when there is a loss of more than 98% of the contact area. Such gross perimeter erosion is unlikely and is not found in recovered armatures. Magnetic liftoff from perimeter erosion does not appear to be a causative mechanism in armature transition. This computational study also provided a platform for testing two FE codes, which showed very good agreement overall
Keywords :
electrical contacts; finite element analysis; magnetic forces; railguns; armature contacts; magnetic blowoff forces; magnetic liftoff; magnetic repulsive forces; perimeter erosion; recovered armature; solid-armature railguns; three-dimensional finite element models; Analytical models; Armature; Computer interfaces; Contacts; Finite element methods; Iron; Magnetic analysis; Railguns; Rails; Testing; Finite element (FE); perimeter erosion; repulsive forces;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2006.887433
