COE NewsNet – February 2007

Advanced composites have emerged as the structural materials of choice for many aerospace applications because of their superior specific strength and specific stiffness properties. First developed for military applications, composites now play a significant role in a wide range of current generation aviation structures. The large commercial transport aviation industry has seen a significant increase in use of composite materials during the past 25 years, and many advances have been made in general aviation and rotorcraft vehicles where composites are used for primary-structure applications.

Over the past ten years, general aviation and the small aircraft industry have steadily increased the number of applications of advanced composite materials in primary and secondary airframe structures. Today’s certified aircraft utilize composite materials as the primary structural material in both the wing and fuselage (pressurized and nonpressurized). These activities have produced many FAA policies that advanced certification and guidance documentation substantially.

As these composite aircraft applications increase, more efficient methodologies are needed to certify these composite airframe structures. The main objective of certification is to test the performance of the aircraft over its intended life and to demonstrate airworthiness and safety of the design. This program assesses current structural testing protocols involved in the certification of composite airframe structures. This project is intended to provide guidance including a “best practice” approach to these tests along with a series of verification on full-scale composite airframe structures.

Objective

The primary objective is to investigate acceptable means of compliance for fatigue, damage tolerance and static substantiation of composite airframes structures. Secondary objectives are:

(a) To evaluate existing analysis methods and building block approach needs for composite airframe structural substantiation.

(b) To investigate realistic service damage scenarios, inspection procedures, and repair procedures suitable for field practice.

In general, composite materials exhibit superior fatigue performance and excellent corrosion resistance relative to metals. However, special considerations must be applied in the fatigue/damage tolerance design due to the increased scatter in both strength and fatigue life. This program will evaluate various approaches for the certification of the structures and investigate methodologies for newer material forms. The program is supported by a number of aircraft companies, which have certified composite aircraft or currently are in the certification process.

The research methodology used in this program will consist of combining existing certification approaches utilized by various aircraft manufacturers with protocol for applying these methodologies. This will allow extension of the methodologies to new material systems and construction techniques. Because these tests are usually the most expensive performed during the certification process, the goal of the program is to provide an efficient certification approach that weighs both the economic aspects of certification and the time frame required for certification testing, while ensuring that safety is the key priority.

The program will involve a number of full-scale demonstration test articles to provide background and examples for the resulting guidance. Because the program is to supply the industry with as much information as possible, partnerships were developed in support of this program. Two aircraft models will be used as typical composite airframe structure: the Beechcraft Starship and Liberty Aerospace XL2 aircraft.

Expected Outcomes

1. Guidelines defining various approaches for the certification of composite airframe structures. This document will include full-scale test results and analysis guidance.

2. Test results for several full-scale tests, with supporting coupon and element testing will support the approaches outlined. These will provide details of the generation of Weibull shape parameters for obtaining load enhancement factors through various fitting models for composite material fatigue data.

Identification of acceptable means of compliance and associated technical issues for demonstration of fatigue, damage tolerance and static strength substantiation of composite airframe structures
Identify procedures to use analysis in support of certification and demonstrate how it can be used with the building block process.

A composite wing installed in a text fixture at NIAR’s Full-Scale Structural Testing Lab (left) and highlighted damage to the structure after testing.

For more information about the Center for Advanced Materials Performance at Wichita State University's National Institute for Aviation Research visit the Web site.

Limited Time Offer: CATIA Student Discount!

For a limited time ENGINEERING.com is offering $25 off the new CATIA Student Version. To qualify for this offer contact Dave Livingstone at dlivingstone@engineering.com.

If you are HEAT educator and you haven’t received coupons to distribute to students, or require more, contact calling Dave Livingstone at (905) 273-9991 ext 244

Engineering Vision Grant Submissions are In!

January 15 was the deadline for submissions to the Engineering Vision Grant. Founded to encourage excellence in engineering education, The Engineering VISION Grant will create a forum to share the ideas of leading and innovative engineering educators. All grant submissions will be posted on the community website at www.catiastudent.com

Final announcement of grant recipient will be made in March.

Thank you to all who have submitted an entry.

For more information on the Engineering Vision Grant visit www.engineeringvision.org

Boeing’s 787 Dreamliner Virtual Rollout – A Great Example of CATIA in Industry!

Boeing 787 Dreamliner employees, along with customers and partners from around the globe gathered for an event to celebrate 2006 accomplishments, which included a virtual rollout of the super-efficient airplane. This virtual rollout event was the culmination of many months of effort by thousands of team members at Boeing and partner sites around the world. Through the use of the 787 program's new digital toolset (provided by Dassault Systèmes), the team has proven the manufacturability of the 787 designs. The multimedia event featured engineering-based simulations, video of production startup and the unveiling of the 787 final assembly production flow.

Since the 787 launch in April 2004, 37 customers have logged 458 orders and commitments, of which 435 are firm orders valued at $68 billion at current list prices, making the Dreamliner the most successful commercial airplane launch in history.

Are you Coming to the COE Conference in Vegas?

The annual COE 2007 Annual PLM Conference & TechniFair on April 29-May 2, 2007 will be held at The Rio All-Suite Hotel in Las Vegas, Nevada.

Do you want to get immediate and usable practical knowledge by attending a selection of more than 200 technical and developmental sessions? Do you want to meet other users of Dassault Systèmes PLM solutions, developers, executive decision makers and vendors to build your contact network. If you answered yes to either of the above, this conference is a great place to be.

Conference highlights are: Leveraging CATIA V5 and Virtools for environment simulation, Teaching CATIA V5 through Record Breaking Design, Formula One Body Design, Mississippi State's Formula One Car Body Design Analysis and Construction and Using Augmented Reality to Display CATIA V5 Models within Real-World Environments.

In addition there will also be Academic Roundtable sessions intended to bring together various members of the academic community to discuss hot topics relevant to academia. Representatives from Dassault Systèmes and ENGINEERING.com will be available to answer questions specific to the needs of the academic and training communities.

The conference also features keynote presentations from top Dassault Systèmes and IBM executives, including Bernard Charles, president and CEO Dassault Systèmes and Scott Hopkins, general manager IBM-PLM Solutions.

For more information and to register, click here.