: This document describes the theory of the Optical Transmission (OPTRAN) code developed to predict the optical performance of aircraft aircrew enclosure transparency designs subjected to operational loads. The theory on which the code is based is described. The OPTRAN ray trace code accounts for thermal and stress optical effects. Geometry is defined by parametric cubic solid. The refraction of incoming light is computed as a function of parametric solid surface outward normals. Angular deviation, polarization effects, and lensing are computer for each ray.

Optical Analysis of Aircraft Transparencies (OPTRAN). Volume 1. Theoretical Manual

: The operation of the optical Transmission (OPTRAN) code developed to predict the optimal performance of aircraft transparencies is described. The code allows the effects of operational loads to be analyzed. User input is defined and job control procedure examples are provided. The operation of finite element thermal and stress analysis codes with which OPTRAN is interfaced is described and references is provided. The operation of several interface codes is also documented. The code accepts input files and generates output files compatible with commercially available finite element pre and post-processing software.

/pdf/optical-analysis-of-aircraft-transparencies-optran-volume-2-cke4oxxtdr.pdf

Optical Analysis of Aircraft Transparencies (OPTRAN). Volume 2. OPTRAN User's Manual

The Analytical Design Package (ADP) has been developed as a part of the Air Force Frameless Transparency Program. ADP is an integrated design tool consisting of existing analysis codes and Computer Aided Engineering (CAE) software. The objective of the ADP is to develop and confirm an integrated design methodology for frameless transparencies, related aircraft interfaces, and their corresponding tooling. The application of this methodology is intended to generate a high confidence for achieving a qualified part prior to mold fabrication. ADP is a customized integration of analysis codes, CAE software and material information databases. The primary CAE integration tool for the ADP is MSC/PATRAN, a commercial-offthe-shelf (COTS) software tool. The open architecture of MSC/PATRAN allows customized installations with different application modules for specific site requirements. Integration of material databases allows the engineer to select a material and those material properties are automatically input into the relevant analysis code. The ADP materials database supports two independent schemas: (1) CAE Design Properties and (2) Processing and Test Data. The design of the ADP places major emphasis on the seamless integration of CAE and analysis modules with a single intuitive graphical interface. This tool has been designed to serve and be used by an entire project team, i.e., analysts, designers, materials experts and managers. The final version of the software was delivered to the Air Force in June 1995. The Analytical Design Package (ADP) is intended to facilitate technology transfer to industry. The analysis system is capable of a wide range of design and manufacturing applications.

/pdf/an-integrated-computer-aided-engineering-tool-for-aircraft-b1zzfnyhkf.pdf

An Integrated Computer Aided Engineering Tool For Aircraft Transparency Design Analytical Design Package - ADP

This study sought to characterize the performance and failure characteristics of a hybrid composite material created by the insertion of 301 stainless steel foils in a composite layup composed of IM7/977-3 preimpregnated unidirectional carbon fiber in single shear bolted joints. The hybrid layup was adapted from a conventional composite layup, and the two are compared in both protruding head and countersunk configurations. A partial shank-only hybrid was also investigated. The hybrid composite demonstrated a marked increase in bearing load capacity with an ultimate bearing load improvement of 37% in the protruding head case and 33% in the countersunk case. Methods, results, and analysis of Nondestructive Investigation (NDI) and bearing testing are presented. Micrographs of sectioned progressive failure samples are presented, which correlate to specific phenomena in the given stress-strain curves. 

Single Shear Bearing Response in Bolted Hybrid Composite Joints

The Fail-Safe Technologies for Bonded Unitized Composite Structures (FASTBUCS) research program is developing and validating analysis methods to predict the damage growth and arrestment behavior of five different composite structural concepts containing damage arrestment features. This paper provides an overview of the entire portfolio and describes the concepts, analysis, and testing being performed. Z-pins, stitches, damage arrest fasteners, and mushroom damage arrestment features were all investigated. The analysis approaches include various cohesive methods built into standard commercial finite element packages, as well as a regularized finite element approach, continuum damage approach, and enhanced Schapery theory. The coupon and small element calibration tests have been conducted. The large-scale multi-axial element tests are currently being performed in order to validate the new analysis methods. 

Michael G. Gran

Papers

An Integrated Computer Aided Engineering Tool For Aircraft Transparency Design Analytical Design Package - ADP

Single Shear Bearing Response in Bolted Hybrid Composite Joints

Fail-Safe Technologies for Bonded Unitized Composite Structures - Overview