Project Title:

Solution-Adaptive Computer Software for Preliminary Structural

ResearchSouth, Inc.
555 Sparkman Dr. Suite 818
Huntsville, Alabama 35816

93-1-03.07   1769  __      AMOUNT REQUESTED $ 70,000

Solution-Adaptive Computer Software for Preliminary Structural
Design of Hypersonic Vehicles

Abstract:

ResearchSouth, Inc. proposes to develop methodology and
preliminary
design computer software for the analysis of stiffened composite
panels used in designing hot structures on hypersonic vehicles.
Phase I of the development will investigate the following major
areas of the preliminary design of panel structures which are
subjected to severe thermomechanical loading during operation. We
will develop algorithms and strategies for determining critical
design condition loads from the output of finite element models
of
the structure. We will investigate at least three approaches: an
automated search program which will evaluate output files from
finite element models and define critical thermomechanical
loading
conditions and structural elements from time-consistent load
histories: a statistical model which uses the finite element data
from large samples and determines the most probable set of design
conditions: and a deterministic mathematical model in which a
functional is formed using the finite element data base with the
design condition combinations being produced by a calculus of
variations minimization solution. We will also develop a buckling
analysis program which uses conventional analytical methods to
define the buckling loads and margins of safety of critical
equivalent stiffened panels. We will investigate, demonstrate and
deliver adaptive meshing software to improve the resolution of
internal loads and the capture of peak moments in stiffened
panels
and substructure for evaluation of local crippling of the hot
structure. Prototype software will be available and delivered at
the end of the Phase I effort. Phase II will extend the concepts
and software to the operational mode, interfacing with most
commercially-available finite element structural packages.
Benefits
to NASA will include more cost-effective preliminary design
programs and more reliable designs.

The structural design software will be used by aerospace,
mechanical, and civil engineers on all disciplines which require
a
conceptual and preliminary design phase. Airplane companies,
automobile manufacturing facilities, watercraft designers,
building
and facility engineers, and bridge construction companies are
among
the potential users for this product.

Preliminary Design, Finite Element Methods, Solution-Adaptive
Methods