Independent Structural Loads Analysis (Space and Missile Systems Center Standard).

摘要

During launch and ascent, a spacecraft and its launch vehicle experience severe structural loads. These loads represent the principal design requirements for most of the launch vehicle and spacecraft structure. The structural design and validation process involves independent contractors and organizations and numerous technical disciplines. The determination of structural dynamic properties, loads, stresses, and structural margins of safety requires specialized testing, extremely large mathematical models, and complex analyses. Significantly complicating the process is the fact that the fully integrated spacecraft/launch vehicle system needs to be addressed, and the integrated system cannot be tested prior to flight. Further complications arise because significant engineering judgment is involved, no single organization controls the overall structural dynamic properties of the integrated system, and schedule and cost considerations play major roles. Launch and ascent structural loads are functions of the dynamic properties of the integrated spacecraft/launch vehicle system. Therefore, design changes in one element can result in load changes in all elements. As a result of the above considerations and lessons learned, a formal Load Cycle Process was developed for use on Air Force program. This standard defines the Government's requirements and expectations for contractor performance in defense system acquisitions and technology developments. Successive sections of this document define the constitutive parts of a loads analysis. These include: the procedure for acquisition of primary launch and ascent loads information in a manner compatible with program schedules and milestones; the criteria to be met by the independent loads analyses; management of, and data requirements for, the independent analyses; and program-peculiar considerations in prescribing the scope of the independent analyses.