Lifetime Analysis of Aircraft Sensors Windows Using NASA STD 5018 Procedure (U)
Abstract
(U) This report applies NASA STD 5018 guidelines to the design of 0.42-meter (m)-diameter circular, single-pane sensor windows for a manned aircraft. Windows made of fused silica, multispectral zinc sulfide, and BK7 glass are considered. A proof pressure test is determined for each window to recommend a safe design life. The window must operate safely at a pressure difference up to 0.71 bar (10.3 pound-force per square inch (lbf/in2)). Design life is determined by the time required for the largest microscopic cracks that could survive the proof test to grow large enough under the influence of the service stress for mechanical failure to occur. Weibull strength statistics are used to estimate the probability of failure of the window in the proof test. An alternative procedure illustrated for BK7 glass employs a 3-parameter Weibull equation with a lower threshold of stress for failure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 29, 2020
- Accession Number
- AD1118772
Entities
People
- Bernadett Bodnar
- Daniel C. Harris
Organizations
- Naval Air Warfare Center, Weapons Division