3201. Structural Weight Estimation for Launch Vehicles

Paper

Abstract

This paper describes a work in progress to develop automated structural weight estimation procedures within the Vehicle Analysis Branch (VAB) of NASA?s Langley Research Center. The VAB performs system studies at the conceptual and early preliminary design stages on launch vehicles and in-space transportation systems. Some examples of these studies for Earth to Orbit (ETO) systems include the Future Space Transportation System, Orbit On Demand Vehicle, Access to Space, and the Personnel Rescue Vehicle. Recently VAB has been asked to assist on a NASA Intercenter Systems Analysis Team (ISAT) to assess Second Generation Reusable Launch Vehicle conceptual designs. To help in this effort finite element based structural analysis tools are being automated and included in a distributed heterogeneous computing environment. This will provide some level of bottoms-up structural weight estimation such that vehicle characteristics and technology improvements effecting performance can be assessed. A challenge to the system being developed is to provide flexibility for differing vehicle configurations and differing structural arrangements of these configurations. A structural component building block approach is proposed and a sample configuration analysis is presented. This approach permits automation of basic FEA entities using utility programs for generic processes such as mass mapping and load case definition. A vehicle configuration is broken into JAVA objects organized in a Work Breakdown Structure (WBS) hierarchy. The JAVA objects work in a commercial computational framework environment to integrate data between the vehicle performance program and the structural analyses required to update that performance calculation. It is hoped that continued development of the system in terms of additional structural component building blocks, additional modeling fidelity, loads definition, and associated JAVA object control of these components will result in an Application Programming Interface (API) that is flexible enough to handle the structural weight assessment needs of a large variety of launch vehicle configurations.