RFI Shielding Effectiveness of Steel Sheets with Partly Welded Seams,

摘要

Current specifications,largely unsupported by experimental data,require weld seams in electromagnetically shielded facilities to be radiographically defect-free. These specifications have necessitated spending $1,000,000for inspection and weld rework at SAFEGUARD missile sites. In a study of the effect of weld defects on the shielding effectiveness of shielded enclosures containing welded seams, Carlson found that weld seams having weld defects under a critical size could provide adequate shielding effectiveness,and that repair of such seams was an unnecessary expense. He suggested that the effect of crack (or slot) width and length on shielding effectiveness be evaluated in a future study that would determine critical sizes for classes of defects and would investigate circumstances in which a flaw might act as resonant antenna. (Author)