Hyphen Innovations
Hyphen Innovations and the United States Air Force (USAF) have collaborated to develop a vibration suppression method which allows for the suppression of vibration stresses by up to 95% in critical turbine engine parts.
The 'inherent Damping via Additive Manufacturing Processes' (i-DAMP) have been developed to address the USAF’s need to improve engine readiness and reduce costs.
Additive manufacturing is leveraged by the likes of the USAF for many reasons, but chief among them is part consolidation. However, monolithic parts are considered to be more susceptible to vibration than a multi-part assembly because a monolithic part can lose the ability to dissipate energy as there are no connection surfaces.
As such, although significant weight savings and increased performance can be realised through part consolidation, there is often a susceptibility to fatigue failure because of the high vibration stresses.
“We saw that AM has huge potential in transforming the aerospace industry, but we knew the obstacle of vibration fatigue failure would hinder that potential,” Hyphen Innovations founder Onome Scott-Emuakpor told TCT. “So, our goal was to find a way to leverage the benefits of AM, minimise the likelihood of vibration fatigue, and give process developers a chance at achieving manufacturing repeatability for game-changing aerospace applications.”
Hyphen Innovations uses affordable manufacturing solutions to assist the Department of Defense and aerospace customers in the development of low-cost and damage-resistant systems for future air defence strategies, efficient propulsion solutions and general aviation applications. The company was founded by Onome Scott-Emuakpor, who previously worked as an aerospace engineer at the Air Force Research Laboratory for 12 years.
SOLUTION
One of the key benefits of i-DAMP is that it supports the simplification of part consolidation while maintaining dynamic stability.
i-DAMP works by strategically identifying void locations for unfused powder in laser powder bed fusion, helping equipment manufacturers fabricate damage tolerant, lighter and more cost-efficient structural components. The i-DAMP technology is applied to the design of a part using an automated computational code that examines finite element results and selects optimal unfused volume locations that avoid high stresses while maximising powder particle interaction.
The mechanism behind i-DAMP technology and unfused powder voids is that the motion and interaction of the powder particles within internal geometries provide vibration suppression under dynamic loading. With i-DAMP, 1% of unfused powder voids in a critical part can sustain more than 10X dynamic loading during high-performance operations.
i-DAMP has been implemented to novel designs using Solidworks CAD files and Ansys finite element analysis capabilities. So far, Hyphen Innovations has used it with parts being printed on a Concept Laser M2 Cusing, 3D Systems DMP Flex 350, and Additive Industries MetalFab1 systems in materials such as Nickel Alloy 718 and 316L stainless steel. Hyphen Innovations says that i-DAMP is agnostic to material type.
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IMPACT
First of all, Hyphen Innovations says i-DAMP can achieve part consolidation without the concern of vibration stresses increasing the likelihood of part failure.
By supporting the use of laser powder bed fusion with minimal post-processing steps, i-DAMP also helps to reduce the manufacturing time of advanced small compressor suites by more than 90%.
It does this by minimising the number of necessary post processing steps and part inspection intervals, which are often unnecessary because of the reduction of critical operational stresses through novel design and vibration suppression. A forged/machined proprietary nickel alloy 718 small turbine engine compressor suite with two heat treatments and a surface finish process takes approximately six months. But by combing laser powder bed fusion with i-DAMP, that process can be reduced to a one-week timeframe with only a final machining step required.
Another impact engineered by i-DAMP is weight reduction. Part-to-part weight reduction is roughly 2% with i-DAMP optimisation, which, per Hyphen Innovations, could save a significant amount of weight considering ‘an airline can save roughly 70,000 USD annually per aircraft if they simply removed magazines from flights.’ However, with an i-DAMP part having significantly lower sustained stresses during operation, the design flexibility increases and opens opportunity for additional weight savings beyond 2%. For example, if >50% stress reduction is guaranteed for a compressor rotor blade subjected to vibration bending loads, the blade thickness can be reduced by roughly 30%, which would also improve the steady stress and max rotational speed capabilities.
“We are working on two i-DAMP applications that will significantly impact MRO costs of gas turbine engines,” Scott-Emuakpor said. “One is fan blade damage resistance that allows parts to experience foreign object damage without failure. The second is combining i-DAMP with additive repair to reliably improve sustainment of old aircraft fan blades. This is the aerospace industry we’re talking about, so the qualification process will be long. But the end-users can see the gold at the end of the rainbow, which is motivation enough for us to press forward with development.”
While Hyphen Innovations has initially targeted its focus at the aerospace and defence sectors, the company believes there is a much broader scope for the application of i-DAMP technology. When considering the implementation to tooling, as well as the ubiquity of vibration in many industries, Hyphen Innovations suggests the benefits of i-DAMP can transcend aerospace applications. According to Hyphen Innovations, industries such as automotive, maritime, space, and household appliances/tools could improve ‘manufacturing processes, reduce time/cost to produce, and even improve quality of life by implementing i-DAMP.’
The next step for Hyphen Innovations is to explore the transitioning of the automated i-DAMP technology into an easy-to-run software with a standard graphic user interface.
“We’ve received lots of interest in many dynamic industries experiencing vibration fatigue failures,” Scott-Emuakpor finished. “We’ve been in communications with steam turbine and industrial gas turbine industries about i-DAMP for damage resistance capabilities. The automotive and racing industries are both interested in lightweighting while minimising vibration, so i-DAMP is intriguing to them. Most recently, the locomotive industry has expressed interest in vibration suppression technology for hard coupling. These are all exciting opportunities for i-DAMP that we can’t wait to explore.”
