A rapid method for creating high fidelity finite element models

Abstract

A process under development at The Boeing Company significantly reduces the time and manpower required to create high fidelity finite element models early in the structural design process. The Rapid Modeling System uses a Boeing developed software application called MANIAC to create a three dimensional geometric model that defines all of the “big bones” structure. MANIAC operates with’% the framework of a commercially available computer aided design package, Unigraphics , to perform the geometry creation functions. The geometric model is designed to be easilyomeshed with finite elements using another commercial software package, MSC/PATRAN . Initial properties, such as thickness and width dimensions, are applied to the geometry based upon historical data for similar parts, using a Boeing developed tool called RAMPAGE. RAMPAGE also supplies a mass distribution for the application of inertia loads to the model. All of the property data is stored in an object oriented database management system that provides a consistent and persistent set of data for all analyses. The Rapid Modeling System has been successfully used by many military aircraft projects at Boeing, and has become an integral part of the structural design and optimization process. The use of finite element modeling as a means for assessing the structural integrity of aerospace vehicles has been in common practice for years. Unfortunately, the time and manpower required to create these models has limited the use of the finite element model (FEM) primarily to the detailed design phase of the vehicle design process. -When used during the preliminary design phase, PEMs have tended to be very simplistic due to the number of configurations under consideration, and the limited budget and time available for analysis. This has lead to non-optimal decisions being made at the beginning of the design process that have caused difficulties further. down the road. Higher fidelity finite element models, with realistic and consistent loads applied to them, would be of definite benefit as early in the process as possible, assuming that the PEMs can be created quickly by a small number of analysts.