Laser Shearography NDT Systems (Dantec Dynamics)

Laser shearography is an optical non-destructive testing (NDT) method that finds sub-surface defects in composite, honeycomb and bonded structures without contact, without couplant and over large areas. A small load (heat or partial vacuum) is applied to the part and laser speckle interferometry measures sub-micrometre surface bending. Weak areas such as delaminations, disbonds or crushed cores show up immediately as isolated fringes in the phase map.

NEXSEN is the distributor of Dantec Dynamics laser shearography systems in Turkey. We handle sales, demonstrations and feasibility studies on your sample parts, installation, operator training and technical service for the FlawHunter, FlawExplorer and FlawScout systems.

The business case for laser shearography

• Higher inspection capacity: Shearography has one of the highest inspection rates of any NDT method. Square metres are covered in a single shot, so the same team inspects far more parts per shift.
• Shorter maintenance and delivery times: No water, gel or couplant; no drying, cleaning or masking. Aircraft, helicopters and wind turbines spend less time on the ground.
• Risks other methods miss: Critical defects such as kissing bonds, disbonds, node bond splits and ply wrinkling are imaged reliably. High probability of detection (PoD) and low false-call rates cut unnecessary teardown and scrap.
• An investment ready for automation: Sensors mount on robot arms, linear axes or XY gantries and talk to a PLC for fully automated, repeatable inspection cells.
• Digital records and traceability: Every measurement is stored as a phase map in Istra4D, making reporting to customers, authorities and auditors easy.

What defects does shearography find?

• Honeycombs and sandwiches: disbonds, cracked or crushed cores, node bond splits, kissing bonds, (aluminium) corrosion between skin and core
• Laminates and overwraps: delaminations, ply wrinkling, fluid ingress, dry spots
• Bondings and coatings: disbonds, dry spots, kissing bonds
• Compounds and ceramics: voids, cracking, abrasion
• Spray foams and sealants: porosity and voids

Depending on the bending stiffness of the material, the load applied and the shearing sensitivity, defects down to about 40 mm below the surface can be detected. The method also reveals internal structure such as ribs, stringers, ply drops, overlaps and splices.

Applications

Aerospace: radomes, nacelles, cowlings, fairings, control surfaces, helicopter rotor blades, satellite solar arrays. Aviation MRO: impact damage and disbond checks in line and base maintenance. Wind power: rotor blade production quality control and field inspection. Marine: hulls, rudders and composite sandwich panels. Defence: composite fuselage, wing and rocket motor structures. Automotive and energy: composite overwrapped pressure vessels, CNG and hydrogen tanks, rubber-to-metal and tyre bonds.

Laser shearography is one of the NDT methods covered by the EN 4179, NAS 410 and ASNT SNT-TC-1A personnel qualification standards. Systems can be manual, semi-automated or fully automated, for post-production quality control or in-service inspection.

Which Dantec shearography system fits you?

• Dantec FlawHunter: handheld system with an integrated vacuum pump and a single cable, for fast, repeatable inspection in the field and after production.
• Dantec FlawExplorer: sensor with 8 laser diodes and a field of view of up to 3.4 × 2.8 m, with thermal or vacuum excitation, manual or robotic.
• Dantec FlawScout: compact, cost-effective sensor for quality control labs, universities and NDT training centres.
• Thermal and vacuum excitation systems: the right loading method for your part and the defects you are looking for.

Read our laser shearography guide for the technology and a comparison with ultrasonic testing. To choose the right system together, send us the material, size and defect types of your part and we will run a free feasibility study on your sample.