Buckling Response of a Large-Scale, Seamless, Orthogrid-Stiffened Metallic Cylinder

Rudd, Michelle Tillotson ; Hilburger, Mark W ; Lovejoy, Andrew E ; Lindell, Michael C ; Gardner, Nathaniel W ; Schultz, Marc R

关键词: BUCKLING;    COMPRESSION LOADS;    CYLINDRICAL BODIES;    LAUNCH VEHICLES;    MANUFACTURING;    SENSITIVITY;    TECHNOLOGY ASSESSMENT;    TEST FACILITIES;    FLOW CHARACTERISTICS;    FINITE ELEMENT METHOD;    MATHEMATICAL MODELS;    RIGID STRUCTURES;    WELDED JOINTS;   

RP-ID  :  M17-6419

学科分类：航空航天科学

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

Results from the buckling test of a compression-loaded 8-ft-diameter seamless (i.e., without manufacturing joints), orthogrid-stiffened metallic cylinder are presented. This test was used to assess the buckling response and imperfection sensitivity characteristics of a seamless cylinder. In addition, the test article and test served as a technology demonstration to show the application of the flow forming manufacturing process to build more efficient buckling-critical structures by eliminating the welded joints that are traditionally used in the manufacturing of large metallic barrels. Pretest predictions of the cylinder buckling response were obtained using a finite-element model that included measured geometric imperfections. The buckling load predicted using this model was 697,000 lb, and the test article buckled at 743,000 lb (6% higher). After the test, the model was revised to account for measured variations in skin and stiffener geometry, nonuniform loading, and material properties. The revised model predicted a buckling load of 754,000 lb, which is within 1.5% of the tested buckling load. In addition, it was determined that the load carrying capability of the seamless cylinder is approximately 28% greater than a corresponding cylinder with welded joints.