Compression, Fatigue, and Stress Studies on NOL Ring Specimens

Abstract

Test methods leading to standards and specifications are necessary for government use and for the glass-filament winding industry. The Naval Ordnance Laboratory (NOL) ring test specimen has been used extensively for the development of such methods. It is attractive as a test vehicle because of its inherent simplicity, ease of manufacture, and high degree of reproducibility. Such a ring is adaptable to the measurement of several important mechanical strength properties under both static and dynamic loading conditions.

Reduction of microvoids in composite laminates fabricated by bladder assisted composite manufacturing (BACM)

“…The circumferential flexural strength, σ f (MPa), of the cylinders were determined by testing the half‐ring segments in three‐point bending as described in Refs. . The span to depth ratio, L (mm), for all flexure tests were maintained at 40 to 1 as recommended by ASTM D790‐10.…”

“…This procedure was used to test the eight half‐ring specimen from each mold configuration and pressure profile set. Because of the high radius to thickness ratios of the ring segments (i.e., greater than 10), the strength of the samples were obtained without accounting for sample curvature . Therefore, the circumferential flexural strength of the composite ring segments were determined as recommended by ASTM D790‐10 using the following equation: where b is the width and d the thickness of the specimen, respectively.…”

Ablative Polymers in Aerospace Technology

“…Problems are occasionally Downloaded by [Tufts University] at 14:19 04 November 2014 encountered with these materials because of premature cracking, failure to transmit the applied load into the structure, and the accumulation of thermal and mechanical stresses. The cracking of a motor case liner during initial pressurization is an example of this type of material limitation [27].…”