Specification for conductors for general purpose aircraft electrical cables and aerospace applications

This work proposes and applies a two-level optimization feature for the design and analysis of reinforced shell structures for aerospace applications. A general-purpose finite element software (NASTRAN) is used as a first-level code to compute the loadings that act on panels. The panels are then optimized using a second-level code (PANDA2), which gives their optimum solutions by taking into account buckling and postbuckling elastic stability constraints. The PANDA2 code, which is based on pseudo-analytical formulations, leads to a considerable reduction of the requested computational efforts compared to the optimization made by NASTRAN. The proposed two-level feature, named NAPAO, builds a loop (between the NASTRAN and PANDA2 codes) that runs until a convergent solution is reached. Those substructures, such as longerons and stiffeners (which are not considered by PANDA2), could be optimized by referring to the solver that is available from NASTRAN. A number of examples that encompass simple structures as well as two complete space vehicles and an unconventional aircraft have been optimized. Metallic as well as composite materials were considered. It can be concluded that NAPAO is a very useful tool for the design process of complex aerospace structures. It gives accurate results and reduces computational costs compared to a standard optimization made when only using the general-purpose code.

Download Full-text

Miniaturized general-purpose architecture for I/O signals handling in aerospace applications

20th DASC. 20th Digital Avionics Systems Conference (Cat. No.01CH37219) ◽

10.1109/dasc.2001.963351 ◽

2002 ◽

Author(s):

M.F. Younis ◽

J.W. Ernst

Keyword(s):

General Purpose ◽

Aerospace Applications

Download Full-text

General-Purpose Coarse-Grained Toughened Thermoset Model for 44DDS/DGEBA/PES

Polymers ◽

10.3390/polym12112547 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2547

Author(s):

Michael M. Henry ◽

Stephen Thomas ◽

Mone’t Alberts ◽

Carla E. Estridge ◽

Brittan Farmer ◽

...

Keyword(s):

Path Dependence ◽

General Purpose ◽

Coarse Grained ◽

Degree Of Cure ◽

Coarse Grained Model ◽

Size Dependent ◽

Aerospace Applications ◽

Model Predictions ◽

First Time

The objective of this work is to predict the morphology and material properties of crosslinking polymers used in aerospace applications. We extend the open-source dybond plugin for HOOMD-Blue to implement a new coarse-grained model of reacting epoxy thermosets and use the 44DDS/DGEBA/PES system as a case study for calibration and validation. We parameterize the coarse-grained model from atomistic solubility data, calibrate reaction dynamics against experiments, and check for size-dependent artifacts. We validate model predictions by comparing glass transition temperatures measurements at arbitrary degree of cure, gel-points, and morphology predictions against experiments. We demonstrate for the first time in molecular simulations the cure-path dependence of toughened thermoset morphologies.

Download Full-text