3355. Reference Models For Structural Technology Assessment and Weight Estimation

Paper

Abstract

Previously the Exploration Concepts Branch of NASA Langley Research Center has developed techniques for automating the preliminary design level of launch vehicle airframe structural analysis for purposes of enhancing historical regression based mass estimating relationships. This past work was useful and greatly reduced design time, however its application area was very narrow in terms of being able to handle a large variety in structural and vehicle general arrangement alternatives. Features of that work such as the utilization of Object Oriented JAVA Programming and the incorporation of flexible commercial FEA and commercial structural design software are retained in this continuing work, but a new emphasis has been placed on making the integrating JAVA modules much more generic. The goal has been to develop a library of JAVA modules which when placed in the desired sequence facilitate the automated structural sizing of a greater variety of component and vehicle systems. The finite element procedures wrapped by JAVA routines now trend towards being more generic in the sense that the routine inputs are not as much design and FEA program specific as they are design and FEA process specific. A later goal in this analysis system development would be to arrive at a working group defined set of JAVA Interface Classes that describe input and output required for particular stages of analysis of automated structural design. Along with standardized input/output parameters there would also be a set of standard data processing functions, which are then useful to the structural designer in providing the flexibility required for designing numerous parts, sub-assemblies, and full vehicle configurations. In JAVA programming terminology these Class definitions become generic Interfaces which are then implementable at any corporate or academic organization utilizing internal and possibly proprietary procedures. Model data may be exchanged between these organizations and will be processable by any of the organizations which have implemented the defined standard Interface. Similar work is ongoing in the area of Simulation Based Acquisition (SBA) via the Simulation Interoperability Standards Organization (SISO) and particularly in the area of integrating distributed simulations by the High Level Architecture – Commercial off the shelf Simulation Package Interoperation Forum (HLA~CSPIF). For those more interested in preliminary design in a collaborative environment the NAVY NAVSEA division has pursued similar themes of modularity and multi-disciplinary interoperability by utilizing a CORBA and IDL (Interface Definition Language) based approach to Simulation Based Design (SBD). A quote from Optimization in the Simulations Based Design Environment by W. A. Kusmik shows the great utility of implementing a formal Simulation Based Design approach.
‘High Potential was evidenced by the ability to integrate high-fidelity modeling and simulation tools to provide insight into overarching system-level performance attributes and the ability of the integration process itself to promote informal collaboration between various domain experts.’
These too are the features being encouraged and developed within the Exploration Concepts Branch to enable functionally and organizationally collaborative multidisciplinary design for the purposes of defining and building vehicle elements which best help us achieve the nation’s vision for manned space exploration.