The National Institute for Aviation Research (NIAR), located on the campus of Wichita State University, is now running at full capacity following several lab renovations and additions. In the past 15 months, NIAR completed major upgrades to its crash dynamics laboratory and wind tunnel, and it opened a new advanced joining laboratory and an aircraft structural testing and evaluation center. In addition, NASA designated the facility the National Center for Advanced Materials Performance.
In January, NIAR dedicated the crash dynamics laboratory and rededicated the Walter H. Beech memorial wind tunnel. Both laboratories underwent multimillion-dollar upgrades to increase their capabilities and effectiveness for the aviation community.
“These were the two most highly anticipated improvements NIAR has made since it was created,” noted NIAR executive director John Tomblin. “It has been more than 50 years since the wind tunnel has seen a major upgrade. Today, it is one of the best tunnels of its kind in the nation.”
The $6 million transformation included installation of new flow-conditioning equipment, a 2,500-hp fan that can maintain test section airspeeds of more than 200 mph, a complete test sequence automation for increased test repeatability and efficiency, a larger viewing window and a heat exchanger and cooling system that limits the temperature in the tunnel. The newly remodeled control room focuses on real-time test information for the client and has a new security system to ensure test-article confidentiality.
The $3 million modernization of the crash dynamics laboratory included installation of a new accelerator sled, 1,000 sq ft of client work/office space and two technical support rooms. A state-of-the-art system replaces the photographic lighting system. This upgrade not only improves the lab’s ability to conduct crash tests for the aviation industry, but it also allows for expansion into the automotive industry.
The servo-hydraulic crash simulator reaches speeds of 50 mph with a 3,300-pound payload and adjusts impact pulse peak to reach up to 65gs (75gs with a 2,200-pound payload). In addition to a sophisticated data-acquisition system, NIAR uses a high-resolution, high-speed digital video system that captures 1,000 frames per second. Sensor-laden anthropomorphic test dummies stand in for occupants.
Recently the crash lab has been preparing to use the new facilities more efficiently. Three new full-time lab technicians and a new full-time lab manager have been hired so the lab can offer extended hours when needed.
“In the past we’ve had to turn away clients who need to get in during a particular time frame,” said lab director Joseph Mitchell. Now the lab can run 18-hour days.
New Labs
The advanced joining laboratory contains a friction stir welding (FSW) gantry. Over the last decade FSW has seen growth in research, development and application; in fact, much of the Eclipse 500’s structure is friction stir welded.
NIAR’s primary FSW research work will be performed in the almost 4,000-sq-ft high-bay advanced joining laboratory. The lab’s five-axis FSW machine has a 120- by 25- by 40-inch work envelope, with the capability to join structures with complex curvatures.
Tomblin said the lab can perform multiple-joint configurations such as butt and lap joints in aluminum aerospace alloys up to five-sixteenths of an inch thick. Prototyping development of complex curvature structures and conducting material and structural testing analysis of structures using FSW will also be conducted at the lab.
The joining lab is applying for a $10,000 planning grant to become part of the National Science Foundation’s Center for Friction Stir Processing (CFSP). CFSP brings together the premier friction stir processing academic institutions in the U.S. and focuses on addressing the needs of aerospace, aeronautic, energy, military and commercial industries in developing friction stir processing.
The lab has proposed four CFSP research programs for development during the planning phase: a performance specification model for friction stir welding and processing; process specification guides for industrial partners; testing and qualification of common aluminum alloy full-scale aerospace structures produced using friction stir welding processes; and evaluation of initial temper and post-weld treatments for optimization of strength, damage tolerance and corrosion resistance of friction stir welded aluminum alloys for aerospace applications.
In September last year, NIAR added a full-scale 46,000-sq-ft aircraft structural fatigue test facility at Beech Field. Called the Aircraft Structural Testing and Evaluation Center, the lab was donated by Raytheon Aircraft. The institute has relocated its aging-aircraft research laboratory to this test facility, which provides proprietary full-scale aircraft fatigue testing services for the aviation industry.
Not surprisingly, Raytheon was the institute’s launch customer for the facility, which provides structural testing for the aircraft manufacturer’s entire product line, including current work on Hawker 4000 (née Horizon) fatigue and static test articles. NIAR’s test facility has so far put the fatigue Hawker 4000 article through more than two lifecycles.
To Infinity…and Beyond
In late August, Oklahoma-based space travel company Rocketplane conducted developmental tests at NIAR’s wind tunnel. The company is continuing testing on the Rocketplane XP, a suborbital spacecraft–derived from the Learjet 25– designed for space tourism.
The model being used for testing was developed by NIAR’s research machine shop. Rocketplane previously conducted several other preliminary tests in the wind and water tunnels at NIAR.
Joseph Huwaldt, chief engineer for Rocketplane, said his company also plans to use NIAR’s full-scale aircraft structural testing and evaluation center to conduct static structure wing tests in early 2007. Rocketplane plans to conduct test flights of the Rocketplane XP before the end of next year and, under an ambitious schedule, to carry its first passengers by mid-2007.
Meanwhile, NIAR’s aging-aircraft and composites labs have begun research on the Beechcraft Starship to understand more about how non-metallic composite structures age. The program is being conducted on behalf of NIAR’s FAA Center of Excellence for Composites and Advanced Materials. Tomblin and Lamia Salah, manager of the fatigue and fracture lab, are the project’s principal investigators.
The FAA will use the results of this program to assess the efficacy of the current emerging nondestructive inspection methods to detect flaws in composite structures.
Some of the issues the program will investigate include the changes in mechanical properties using coupon and element level testing; degradation in physical properties and resin chemistry; effectiveness of repairs; material degradation due to heat, humidity and ultraviolet radiation; and bearing conditions and/or failures around holes and fasteners.
“With the large number of aircraft flying with composite components, it is imperative that as an industry we understand the effects of age, both calendar and flight-hour related, on composites before a structural failure,” noted aging-aircraft manager Melinda Laubach.
On a similar note, three of NIAR’s labs are evaluating the effects of aging on the decommissioned composite tail of a Boeing 737. Although researchers will perform the non-destructive evaluation in accordance with the current field methods, the institute is also using more sophisticated techniques such as 3-D photogrammetry and laser holography. It will also conduct detailed structural evaluation to measure any changes in thermal, chemical and mechanical properties.
Composite Material Standardization
Last year, NASA tapped NIAR to develop national standards for composite materials used in aircraft manufacturing. The aviation composite materials standards are similar to the mil-spec standards–developed during the early 1940s–for today’s aluminum aircraft materials. Working in conjunction with the NASA Langley Research Center, NIAR established the National Center for Advanced Materials Performance to accomplish this objective.
“The institute’s National Center for Advanced Materials Performance will develop the process by which aviation composites and advanced materials will be validated through a centralized database. These quality-assurance standards will be used by all aircraft and parts manufacturers to reduce costs and cycle times for new products,” said Tomblin.
He said NIAR currently provides some 70 percent of the composite material research undertaken by the FAA. The institute will make the most of this extensive composite experience in developing the new national standards.
Increasing the efficiency of advanced material applications for new aircraft models and decreasing the cost of materials will be the primary focus of NIAR’s NASA-designated center for advanced material performance.
According to Tomblin, the institute expects a trend toward more prevalent use of composite materials. In fact, Boeing and Airbus have already demonstrated this anticipated growth with the 787 Dreamliner and A380 megaliner, respectively.
“Advances in vehicle development will likely accelerate during the next decade as emerging technologies are applied to design and placed into production throughout the aircraft industry,” concluded Tomblin.
