where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -

Technical Discussions
Maurice Grandsoult
Maurice Grandsoult
15:50 Jan-30-2009
MRI Composites

Bell Helicopter in Hurst, Texas (basically a suburb of Fort Worth) NDI'd their V-22 Grip in the early days of the program using MRI Magnetic Resonance Imaging, around 1985 to 1989. The Grip puts the angle into the rotor blades as they rotate, and is a thick-walled, hollow, dog-bone-like composite structure, probably 5 foot long or so, that surrounds the centrifugal, load-bearing yoke which is attached to the rotor blades. Initially Bell used the medical MRI resources of the local HEB Hurst Euless Bedford Hospital, but I remember there was a budget proposed before I left in 1989 for Bell to buy their own machine, as the MRI fees apparently pretty much paid for the local Hospital's machine. I do not know if Bell purchased the proposed MRI. It was apparently the only way they could effectively examine the Grip structure, which an Aviation Weekly report at the time described as the single most complex composite structure being built. As the slightly earlier composite Beech Starship was having certification problems with the FAA, the MRI was Bell's approach to getting the FAA to understand and accept the relatively new Graphite Epoxy composite materials. I remember conversations that related porosity issues with the Grip, but when destructively tested, it proved fantastically strong, exceeding the anticipated life by half again as I recall - even with the MRI-observed "defects". The MRI inspection was a major factor in understanding and accepting this highly complex and thick-walled composite part. Obviously, composites could not be treated like metals, where any porosity would significantly reduce their strength. Even with very minor, and now acceptable porosity issues, the V-22 is a great aircraft. Despite a few early technical issues, resulting in a couple of highly unfortunate crashes, which had NOTHING to do with the integrity of the structural composites nor with the basic airworthiness of the tilt rotor design, and which is quite typical for new and highly innovative aircraft designs if anyone reviews similar programs, it is currently serving extremely well with the US armed forces. Maurice Grandsoult ex-Bell Helicopter Rotor Blade Manufacturing Engineer Jan 2009

Richard Freemantle
NDT Inspector, Consultant, R&D
Wavelength NDT Limited, United Kingdom, Joined Nov 1998, 16

Richard Freemantle

NDT Inspector, Consultant, R&D
Wavelength NDT Limited,
United Kingdom,
Joined Nov 1998
18:14 Feb-04-2009
Re: MRI Composites
In Reply to Maurice Grandsoult at 15:50 Jan-30-2009 (Opening).

Dear Maurice,

This is a very interesting post. Can you comment on the ability of MRI to resolve small defects within the laminate such as individual pores in groups of porosity, fibre waviness (also called marcelling) and resin rich areas ? I have seen very impressive X-ray and Microfocus X-ray images on a number carbon fibre laminates using computed tomography (CT) which can image very small features within the laminate and wondered how it compared to the MRI systems that you have worked with. For example see:


My interest here is in the use of CT methods to 'see' what is actually in the composite material in order to validate and qualify measurements made using ultrasound techniques, much in the same way that standard X-ray is used to verify and size weld defects in test specimens that are to be inspected and sized using ultrasound. My understanding is that standard X-ray imaging is pretty difficult on composites, and although impressive, high resolution Microfocus X-ray CT can usually only image a small volume of material.

Best regards,



Product Spotlight

NEW - TD Focus-ScanRX

The NEW Next Generation Advanced UT platform, TD Focus ScanRX - Also available as a card stack solut
ion. Key Improvements 1. Data acquisition is significantly faster than current design 2. Better aesthetic – closely aligns with HandyScan RX 3. Improved IP rating (Target IP66) 4. Ruggedized housing 5. Connectors are protected from impact and ingress 6. Integrated stand and separate retractable handle easy to keep clean) 7. Touchscreen with ruggedized display glass 8. 3-Axis encoder input

Wireless TOFD scanner

Quick, accurate and highly reproducible welds testing. The System operates wirelessly and is compat
ible with any type of Windows based Laptop, Desktop or Tablet.

MUSE Mobile Ultrasonic Equipment

The MUSE, a portable ultrasonic imaging system, was developed for in-field inspections of light-weig
ht structures. The MUSE consists of a motor-driven manipulator, a water circulation system for the acoustic coupling and a portable ultrasonic flaw detector (USPC 3010). The MUSE provides images of internal defects (A-, B-,C- and D-scan).

Swift & Scorpion2 - a state-of-the-art remote-control ultrasonic crawler

The Swift and Scorpion2 dry-coupled, remote-access ultrasonic crawler bring major efficiency and d
ata improvements to tank shell inspections and other structures such as vessels and offshore installations.

We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
this is debug window