Investigation of Transport Airplane Fuselage Fuel Tank Installations under Crash Conditions.

摘要

This report describes the initial follow-on effort to a recently concluded study described in 'Fuel Containment Concepts - Transport Category Airplanes' which concluded that a short term test program involving fuselage mounted fuel tank installations be conducted. The three contemporary fuel tank installation configurations investigated in this study include: Conformable tank containing a bladder and supported within a dedicated structure; Double wall cylindrical strap in auxillary tank; and Bladder cells fitted in the lower fuselage. This report reviews existing crash design criteria, as well as current proposals which could affect fuel tank installations. Program KRASH was used to help evaluate the performance of a fuselage mounted tank when subjected to dynamic loads. A total of 21 cases were analyzed, including 12 vertical impacts and 9 longitudinal pulse conditions and/or configurations. The analytical models included 120-inch sections, 300-inch segments and full airplane representations. Results in the form of floor and fuel tank accelerations, floor and fuel tank attachment loads and fuselage crush were obtained. Two test conditions are proposed to represent conditions that best meet the crash design criteria developed in a previous FAA sponsored parametric study, as well as to recognize realistic structures and tests that can be run. A preliminary test plan is included. (kt)