2406. Advanced Fuselage Weight Estimation for the New Generation of Transport Aircraft

Paper

Abstract

The airlines are forced to use efficient aircraft due to the hard competition in air traffic. Changes in the airline network, the limited number of slots and the growing rates of passenger and freight require aircraft with high transport performance. This leads to aircraft configurations with high passenger and freight capacities. The fuselage geometry for these types of aircraft can diverge from the conventional design. Also the ongoing studies for the second generation of supersonic aircraft show fuselage designs and physical effects of a new quality. Weight estimations for the resulting new fuselage shapes (e.g. double deck or area ruled configurations) are still a challenging task. Accurate weight prognosis without powerful software tools is becoming an almost hopeless goal. A precise and reliable fuselage weight estimation tool is basis for the assessment of the viability of a new aircraft and has therefore a direct influence on the project. Since the knowledge about the design in the pre-development phase is very limited the software has to include multidisciplinary interactions between loads, structure, and materials. This paper details the process of the fuselage weight estimation method used in the weights prognosis department at Daimler-Benz Aerospace Airbus. Based on simple input data the software creates a numeric 3-D model of the exposed fuselage surface. The position and size of cutouts can be defined by the program user. In the loads module the introduction of external forces and the calculation of internal loads (due to mass distributions of pay-load, systems and structure) are considered. Certification rules, manufacturing procedures, material/structural fatigue and flight/mission envelopes are taken into account. The structure weight calculation is based on classical theories for strength and stability. For the inclusion of the elastic behavior of the fuselage the structural deformation is calculated by the software. The software tool FAME-F (Fast and Advanced Mass Estimation of Fuselage) is described with emphasis on the multidisciplinary character of the computer approach. This approach allows for fast parametric studies and determination of sensitivities. The development of the software tool FAME-F shows how weight engineering can contribute to the essential reduction of aircraft developing time and costs.