Test & Measurement

Applying the Dynamic Inertia Measurement Method to Full-Scale Aerospace Vehicles

Researchers have begun testing on large articles in conjunction with ground vibration tests.

Researchers at NASA’s Armstrong Flight Research Center have been interested in using the Dynamic Inertia Measurement (DIM) method on full-scale aerospace test vehicles, given its advantages over traditional methods for determining the mass properties of such vehicles. Developed at the University of Cincinnati, the DIM method uses a ground vibration test setup to determine mass properties using data from frequency-response functions. The method has been successfully tested on a number of small-scale test articles — including automobile brake rotors, steel blocks, and custom fixtures — but until now, has had limited success being tested in larger applications. Armstrong’s recent efforts, in conjunction with ground vibration tests, represent a step forward in applying the DIM method successfully to full-scale aerospace vehicles.

Posted in: Briefs, Test & Measurement, Measurements, Vibration, Aircraft, Spacecraft, Vehicle dynamics
Read More >>

Modules for Inspection, Qualification, and Verification of Pressure Vessels

This automated, modular, standardized system features interchangeable probes.

After decades of composite over-wrapped pressure vessel (COPV) development, manufacturing variance is still high, and has necessitated higher safety factors and additional mass to be flown on spacecraft, reducing overall performance. When liners are used in COPVs, they need to be carefully screened before wrapping. These flaws can go undetected and later grow through the thickness of the liner, causing the liner to fail, resulting in a massive leakage of the liner and subsequent mission loss.

Posted in: Briefs, Test & Measurement, Failure modes and effects analysis, Containers, Composite materials, Inspections, Spacecraft
Read More >>

In-Flight Pitot-Static Calibration

This precise yet time- and cost-effective method is based on GPS technology using output error optimization.

NASA’s Langley Research Center has developed a new method for calibrating pitot-static air data systems used in aircraft. Pitot-static systems are pressure-based instruments that measure the aircraft’s airspeed. These systems must be calibrated in flight to minimize potential error. Current methods — including trailing cone, tower fly-by, and pacer airplane — are time- and cost-intensive, requiring extensive flight time per calibration. NASA’s method can reduce this calibration time by up to an order of magnitude, cutting a significant fraction of the cost. In addition, NASA’s calibration method enables near-real-time monitoring of error in airspeed measurements, which can be used to alert pilots when airspeed instruments are inaccurate or failing. Because of this feature, the technology also has applications in the health usage and monitoring (HUMS) industry. Flight test engineers can be trained to use this method proficiently in 12 days without costly specialized hardware.

Posted in: Briefs, Test & Measurement, Calibration, Pitot-static instruments, Technician training, Test equipment and instrumentation
Read More >>

Magnetostrictive Pressure Regulating System

The regulator system offers precise operation with response times up to an order of magnitude faster than current technologies.

NASA’s Marshall Space Flight Center has developed a set of unique magnetostrictive (MS) technologies for utilization in pressure regulation and valve systems. By combining MS-based sensors with a newly designed MS-based valve, Marshall has developed an advanced MS regulator. This innovative approach provides both a regulator and a valve with rapid response times. In addition, the components are lightweight, compact, highly precise, and can operate over a wide range of temperatures and pressures. A prototype of the MS valve has been developed and NASA is seeking partners for licensure of this novel technology.

Posted in: Briefs, Instrumentation, Sensors and actuators, Magnetic materials, Valves, Reliability, Lightweighting
Read More >>

Shape Sensing Using a Multi-Core Optical Fiber Having an Arbitrary Initial Shape in the Presence of Extrinsic Forces

This technology can be used for aerospace safety, medical applications, robotics, and space exploration.

NASA’s Langley Research Center has demonstrated a patent-pending method and apparatus for determining the position, in three dimensions, of any point on an optical fiber. The new method uses low-reflectance Fiber Bragg Grating (FBG) strain sensors in a multicore fiber to determine how any point along that fiber is positioned in space. The characteristics of optical fibers and the FBGs vary with curvature, and by sensing the relative change of FBGs in each of three or more fiber cores, the three-dimensional change in position can be determined. By using this method in monitoring applications where optical fibers can be deployed — such as in structures, medical devices, or robotics — precise deflection, end position, and location can be determined in near real time. This innovative position detection method offers 10 times greater positional accuracy than comparable optical techniques.

Posted in: Briefs, Instrumentation, CAD, CAM, and CAE, Fiber optics, Sensors and actuators
Read More >>

Magnetic and Raman-Based Method for Process Control During Fabrication of Carbon-Nanotube-Based Structures

The methodology enables high quality and high yield with about 30% weight reduction over carbon composite materials.

NASA’s Langley Research Center has developed an innovative magnetic and Raman-based method for macroscopic process control during fabrication of carbon-nanotube-based structures. The development of super-strong, lightweight materials based on carbon nanotubes promises new materials with the strength of current carbon composite materials, but at substantially less weight. The development of these new materials is dependent upon nanotube quality, alignment, and load transfer between individual nanotubes in the structure. However, current fabrication process controls are limited to time-consuming microscopy testing at intermittent stages during processing. NASA’s innovative method can be applied during nanotube structure fabrication to obtain real-time feedback on critical processing parameters during fabrication. Moreover, the method is compatible with in-line fabrication processes.

Posted in: Briefs, Instrumentation, Fabrication, Composite materials, Lightweight materials, Nanotechnology, Quality control
Read More >>

AGM Thumbtack™ Valves for Small Enclosures: Smaller and Drier

Sensitive equipment such as optics and electronics can be damaged by humidity and condensation. Placing moisture-sensitive equipment inside a sealed enclosure reduces the risk of damage, but temperature and pressure variations can be problematic for a sealed enclosure if it does not have a pressure-relief mechanism.

Posted in: White Papers, Defense, Electronics, Electronics & Computers, Instrumentation
Read More >>

Choosing the Right Hardware for Testing in Harsh Environments

Testing in rugged applications often includes testing in extreme temperature ranges, which can add constraints to hardware. Cold-start engine testing, for example, uses a test cell that can drop to -40 °C and requires continuous data acquisition such as temperature, pressure, and other various measurements. Placing hardware that is not built to withstand this range into harsh environments can cause components within the hardware to work incorrectly and result in incorrect data or damage to the hardware.

Posted in: Articles, Test & Measurement, Cold weather, Hardware, Test equipment and instrumentation
Read More >>

Keysight Technologies Engineering Education and Research Resources DVD 2016

Keysight is enabling the next generation of engineers to tackle and solve the toughest electronic design and test challenges. With 200 new items in areas relating to education and research (Software Design & Simulation Solutions; Communications Technology; Test & Measurement Science; Nanotechnology & Material Measurement; Power, Energy & Automotive; and Classroom Applications), it includes application notes, white papers, case studies, videos, webcasts, and details on various Keysight solutions. Order your DVD today!

 

 

Posted in: White Papers, Electronics & Computers, RF & Microwave Electronics, Test & Measurement
Read More >>

In-Flight Pitot-Static Calibration

This precise yet time- and cost-effective method is based on GPS technology using output error optimization.

NASA’s Langley Research Center has developed a new method for calibrating pitot-static air data systems used in aircraft. Pitot-static systems are pressure-based instruments that measure the aircraft’s airspeed. These systems must be calibrated in flight to minimize potential error. Current methods — including trailing cone, tower fly-by, and pacer airplane — are time- and cost-intensive, requiring extensive flight time per calibration. NASA’s method can reduce this calibration time by up to an order of magnitude, cutting a significant fraction of the cost. In addition, NASA’s calibration method enables near-real-time monitoring of error in airspeed measurements, which can be used to alert pilots when airspeed instruments are inaccurate or failing. Because of this feature, the technology also has applications in the health usage and monitoring (HUMS) industry. Flight test engineers can be trained to use this method proficiently in 12 days without costly specialized hardware.

Posted in: Briefs, Test & Measurement, Calibration, Pitot-static instruments
Read More >>

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.