Supplier Spotlight

Video Exclusives

Plasma wind tunnel testing

Watch the first simulated re-entry of a full-sized spacecraft in a plasma wind tunnel as the The Scirocco facility tests the Qarman cubesat.

Click here to watch video

18 July, 2018



Sonic boom acoustic tests

This video, from a NASA Social event at Armstrong Flight Research Center, shows an F/A-18 producing a regular sonic boom at 0:43 and and then a low “boom” by performing the dive maneuver at 02:34. NASA researchers are preparing for public tests of technology designed to reduce the noise of sonic booms

Click here to watch video

03 July, 2018



Autonomous vehicles explained

Safran’s SimplyFly! light hearted series of video’s takes on autonomous vehicles - how will they work and what are the main challenges? Learn more about the topic by watching this video.

Click here to watch video

20 June, 2018



 

To watch more videos, click here

With Airbus' Zephyr drone pushing the limits of aviation to reach an altitude of 74,000ft in the stratosphere during test flights, we would like to ask - where do you think the atmosphere ends and space begins?

News

Sandia test demonstrates explosives alternative

Sandia National Laboratories has successfully demonstrated a new, more environmentally friendly method to test a rocket part to ensure its avionics can withstand the shock from stage separation during flight.

The new method—called the alternative pyroshock test—used a nitrogen-powered gas gun to shoot a 100lb steel projectile into a steel resonant beam, which then transfers energy through a resonant cone attached to the part being tested. The resulting energy transfer mimics the conditions of stage separation in space. The first test of this type using the flight hardware was completed this spring.

Until now, pyroshock tests to ensure aerospace parts were ready for the rigors of flight had used explosives encased in lead to provide the impacts to parts needed for such experiments, said mechanical engineer Mark Pilcher. The lead and explosives were environmental hazards, so cleanup was costly and time-consuming. The Sandia Labs team wanted a better approach.

"We recognized early in the program that we need to seek out alternative test methods in order to reduce our hazardous work exposure, minimize environmental waste and develop a controlled and repeatable test capability," Pilcher said.

"Investigating a large-scale nonexplosive gas gun test became a reality when we partnered with Sandia's large-scale mechanical test facilities. The combined team worked hard to get to this test."

Hopkinson bar technology proved a more controllable alternative to explosives

Asked to research whether an alternative means of testing was possible using a gas gun, Sandia mechanical engineer Bo Song turned to a 1in-diameter Hopkinson bar. The Hopkinson bar was first suggested in 1914 by Bertram Hopkinson, a British patent lawyer and Cambridge University professor of mechanism and applied mechanics, as a way to measure the pressure produced by explosives. It was further modified in 1949 for dynamic stress-strain measurements of materials.

In Sandia's Experimental Impact Mechanics Laboratory, Song and his team conducted small-scale testing with a metal rod about 20 times smaller than that used in the full-scale test. They discovered the Hopkinson bar technology could provide the frequency levels and the mechanical energy needed in the large-scale test to recreate conditions found during flight.

Song's team conducted more than 50 tests. They looked at what types of projectiles to use, how fast the gas gun needed to shoot, how to design a Hopkinson bar-type apparatus called a resonant bar at a larger scale, how to design a steel resonant cone to transfer the energy to the object being tested, and how to manipulate the pulse of energy using small copper ‘coins’ called programmers or pulse shapers, which were placed on the surface of the resonant bar.

"The most difficult part was designing the programmers, or pulse shapers, because we had to select the right material, geometry and dimensions," Song said. "We got a lot of experience through this kind of testing for the future large-scale testing. The same concept can be used for a variety of defense and space applications. This provides a new path for pyroshock testing, but very clean and more controllable, and will save a lot of costs."

The next phase of the alternative pyroshock test applied the Hopkinson bar technology to a pneumatically driven gas gun.

For this test, the gas gun was not required to reach its maximum capacities. The 60ft-long gas gun used compressed nitrogen gas to shoot metal projectiles into a resonant beam coupled with a resonant cone to expand the final diameter to interface with the rocket part, essentially a hybrid version of a large-scale Hopkinson bar.

September 6, 2017

Written by Michael Jones


RECEIVE THE
LATEST NEWS


Your email address:



Read Latest Issue

Read Latest Issue

Web Exclusives

Customers appreciate the Global 6000’s smooth ride, but it wasn’t until Bombardier conducted a series of innovative tests that there was quantifiable data to support their claims
Click here to read more

Marine Dumont, business development manager, Kistler Instruments outlines how innovation in dynamometers is enabling clearer images of Earth from satellites 
Click here to read more

Steve Drake, NDT market manager for Ashtead Technologies, describes how the rapid deployment of the latest borescope equipment to Africa helped a business aviation operator make tough decisions about a grounded aircraft 
Click here to read more

Hardware-in-the-loop systems have helped to reduce flight testing of Saab's latest fighter jet, writes National Instruments in this case study
Click here to read more

An experiment is set to be launched from the International Space Station this month which turns the normal approach to space on its head – instead of putting things into space, this experiment aims to test ways to take things out of space. 
Click here to read more


Supplier Spotlight

Supplier SpotlightClick here for listings and information on leading suppliers covering all aspects of the aerospace testing industry. Want to see your company included? Contact tom.eames@ukimediaevents.com for more details.

Submit your industry opinion

Industry BlogDo you have an opinion you'd like to share with the aerospace testing community? Good or bad, we'd like to hear your views and opinions on the leading issues shaping the industry. Share your comments by sending up to 500 words to anthony.james@ukimediaevents.com

Submit Your Recruitment Ad

Recruitment AdTo send us your recruitment advertising or to receive information on placing a banner please email ben.sampson@ukimediaevents.com