Results from Army, university tests could improve vibration testing for auto, aviation industries
Results from a recent study that looked at how battlefield-born vibrations, like those from blasts and heavy armoured vehicles, for example, are leading research scientists to rethink military vehicle testing and evaluation methods that could also, eventually, improve automotive and aviation industry standards.
A group of Army and University of Maryland researchers and engineers have developed reliability tests to better capture unforeseen failures in ground and air vehicle designs before the military adopts systems and components.
Ed Habtour, principal investigator on the project at the US Army Research Laboratory (ARL), said the physics of failure (PoF) based reliability models and test methods developed by ARL, US Army Materiel Systems Activity Analysis, Aberdeen Test Center, the University of Maryland’s Center for Advanced Life Cycle Engineering (CALCE), Team Corporation and Data Physics Corporation were run on the Team Tensor 900 six degrees of freedom (6-DoF) shaker, one of only two of its kind in the world.
The project receives support from the industry-government consortium which sponsors this research at CALCE. The consortium consists of leading electronics manufacturers and users from both military and commercial arenas, said Dr Abhijit Dasgupta, professor at the University of Maryland’s CALCE.
Instead of the current practice of vibrating a product sequentially for every axis, the Tensor 900 is capable of vibrating a product in three translational and three rotational motions simultaneously. Results provide a way for researchers to better understand how components fail under the military’s – and industry’s – most rigorous conditions where vibration is extreme, and with this information, ground and air vehicles can be built better to guard against known vulnerabilities.
The sequential and simultaneous vibration comparison studies have shown that the traditional sequential axial testing is inadequate, expensive, time consuming and provides misleading non-conservative reliability predictions. “When we saw the results, it was so surprising to us that we wanted to make sure we could repeat them,” said Habtour. He said the tests results could “really change the way industry conducts vibration testing” for cars, trucks and aircraft.
The current military standard calls for systems, equipment, other machinery and devices to withstand tough climate condi- tions. Military Standard 810G is the current specification that the Department of Defense (DoD) has in place for equipment to survive and thrive, and this same standard has been adopted by the automotive, aerospace and electronics industry.
Changes to the military standard are going to impact these industries positively by truly improving reliability while reducing testing time and cost, Habtour said.
ARL is working closely with the US Army Test and Evaluation Command, Aberdeen Test Center and Redstone Testing Center to update testing standards such as MIL-STD-810G based on the outcomes of this research.
“In military applications, the reliability of components and devices play a vital role in mission success because some of these devices provide crucial tasks such as control, guidance, communication, and reconnaissance,” Habtour said.
For years, he said, the military has had to rely on commercially-available components that are not designed for military applications. But this has led to concerns about their reliability in harsh battlefield environments. Nonetheless, these components can be easily ruggedised with the aid of the multiaxial shaker that can simulate a “real-world” vibratory environment.
The two-year effort covers components in most ground and air vehicles from 20 to 3,000 hertz, such as AH-64, UH-60, C-130, MATV, JLTV, military robotics and commercial automotives and aircraft. The work does not cover the vibration spectrum of projectiles or missiles in flight.