Badania ultradźwiękowe wielogłowicowe elementów konstrukcji Bolesław AUGUSTYNIAK.

Badania ultradźwiękowe wielogłowicowe elementów

konstrukcji

Bolesław AUGUSTYNIAK

Plan

• Historia

• Zasada działania

• Przykłady zastosowań

http://www.olympusndt.com/en/tomoview/

Historia układów wielogłowicowych

In 1971, just as the CRC Automatic Welding System was beginning to show promise, Vetco Offshore Inspection saw the CRC system in Houston, Texas and sent a welding “bug” and band along with some sample welds to their Canadian office. There, a young engineer named Tony Richardson designed the first UT inspection system for the CRC welding process

Tony Richardson with the first multiprobe scanner mounted on a CRC welding band

Historia układów wielogłowicowych...

Since 1959, RTD b.v. in the Netherlands have been working on options for the pipeline industry. An example of one of the early efforts made by RTD is shown on left. This early version of the Rotoscan shows a split ring support on which the probe holder moves. A single probe was used with a single channel ultrasonic instrument. Three separate UT instruments were used for each of the three probes: two probes set opposite each other to detect longitudinalflaws and a third probe to detect transverse defects.

RTD three-probe Rotoscan (single-channel unit shown, around 1959)

Historia układów wielogłowicowych ...

In the early 1990s SGS Gottfeld in Germany had designed its MIPA system

The monitor display consisted of a series of bands for each channel with amplitude represented as a colour (a single line C-scan).

Historia układów wielogłowicowych ...

In 1996 WeldSonix introduced their system. This system came up with a smaller scanning head and full waveform data collection for allchannels but also used the industry-accepted strip chart format.

Historia układów wielogłowicowych

...

In 1997 R/D Tech decided to conform to the data presentation initiated by RTD nearly 20 years earlier and developed a newer version of both hardware and software based on their Tomoscan™ technology. In 1998/99 R/D Tech used this display (see Figure 1-12) for the data collected by the new phased array system they had developed.

Zasada działania głowic mozaikowych

The main feature of phased array ultrasonic technology is the computercontrolledexcitation (amplitude and delay) of individual elements in a multielement probe. The excitation of piezocomposite elements can generate an ultrasonic focused beam with the possibility of modifying the beam parameters such as angle, focal distance, and focal spot size through software. The sweeping beam is focused and can detect in specular mode themisoriented cracks.

Zasada działania głowic mozaikowych

During transmission, the acquisition instrument sends a trigger signal to the phased array instrument. The latter converts the signal into a highvoltage pulse with a prepro-grammed width and time delay defined in the focal laws. Each element receives one pulse only. This creates a beam with a specific angle and focused at a specific depth. The beam hits the defect and bounces back.. The signals are received, then time-shifted according to the receiving focal law. They are then reunited together to form a single ultrasonic pulse that is sent to the acquisition instrument.

Ogniskowanie wiązki i zmiana kąta padania

Basic: beam focusing principle for (a) normal and (b) angled incidences.

There are three major computer-controlled beam scanning patterns

1. Electronic scanning

Electronic scanning: the same focal law and delay is multiplexed across a group of active elements; scanning is performed at a constant angle and along the phased array probe length (aperture). This is equivalent to a conventional ultrasonic transducer performing a raster scan for corrosion mapping or shear wave inspection. If an angled wedge is used, the focal laws compensate for different time delays inside the wedge.

2. Dynamic depth focusing

Dynamic depth focusing, or DDF (along the beam axis): scanning is performed with different focal depths. In practice, a single transmitted on reception for all programmed depths.

3. Sectorial scanning

Sectorial scanning (also called azimuthal or angular scanning): the beam ismoved through a sweep range for a specific focal depth, using the sameelements; other sweep ranges with different focal depths may be added.The angular sectors may have different values..

Delay Laws, or Focal Laws -

Example of delay values on individual elements for steering the beam of alongitudinal wave from .30° to +30°.

Zmiana kąta

Different types of focusing will generate different S-scan views: (a) projection S-scan is very useful for narrow-gap weld inspection; (b) true depth is useful for detection and sizing defects at a constant depth (for example, inner wall fatigue cracks); (c) half-path S-scan is the most commonly used S-scan; (d) focal plane S-scan is useful for detection of lack of fusion along the weld geometric preparation.

Phased array probes installed on the wedge provide delay laws with different shapes, based on Fermat’s principle of minimum arrival time along a specific path

Delay Laws, or Focal Laws - 1

Delay Laws, or Focal Laws - 2

If the beam deflection is sectorial (azimuthal), and the probe has no wedge, the delay on identical elements will depend on the element position in the active aperture and on the generated angle

Głowice mozaikowe w działaniu 1

7.5MHz 60 element probe. Images show incremental increase of number of elements from 5 to 25 elements each starting at element number 5 in the array. Each

image is taken at 15mm from the glass surface

http://www.ndt.net/article/wcndt2004/html/htmltxt/127_ginzel.htm

7.5MHz 60 element probe. Images show incremental increase of number of elements from 5 to 25 elements each starting at element number 5 in the array.

Głowice mozaikowe w działaniu 2

10MHz 32 element probe. Images show a beam both focused and angled. On the left the beam is focused at 25mm sound path and angled at 45° for the shear mode while on the right the beam is focused at 25mm and angled at – 45° in shear mode.

http://www.ndt.net/article/wcndt2004/html/htmltxt/127_ginzel.htm

Układ blokowy defektoskopu mozaikowego

Basic components of a phased array system and their interconnectivity.

Prezentacja typu S-scan

Detection of four side-drilled holes (SDH): (a) sectorial scanning principle; (b) S-scan view using ±30°.

Typically, phased arrays use multiple stacked A-scans (also called B-scans) with different angles, time of flight and time delays on each small piezocomposite crystal (element) of the phased array probe. The real-time information from the total number of A-scans, which are fired for a specific probe position, are displayed in a sectorial scan or S-scan, or in a electronic B-scan

Metoda kombinowana

Advanced imaging of artificial defects using merged data: defects and scanning pattern (top); merged B-scan display (bottom).

Advanced imaging can be achieved by a combination of linear and sectorial scanning with multiple-angle scans during probe movement. S-scan displays in combination with other views lead to a form of defect imaging or recognition. Figure illustrates the detection of artificial defects and the comparison between the defect dimensions (including shape) and B-scan data.

Połączenie fal podłużnych i poprzecznych

A combination of longitudinal wave and shear wave scans can be very useful for detection and sizing with little probe movement In this setup, the active aperture can be moved to optimize the detection and sizing angles..

Detection and sizing of misoriented defects by a combination of longitudinal wave (1) and shear wave sectorial scans (2).

Wiązki zogniskowane cylindrical focused beam

Cylindrical, elliptical or spherical focused beams have a better signal-to-noise ratio (discrimination capability) and a narrower beam spread than divergent beams. Figure illustrates the discrimination of cluster holes by a cylindrical focused beam...

Discrimination (resolution) of cluster holes: (a) top view (C-scan); (b) side view (B-scan).

Dalsze usprawnienia : ruch sondy i detekcja w czasie rzeczywistym

Real-time scanning can be combined with probe movement, and the data merged into a single view This feature offers the following benefits: • High redundancy, • Defect location • Accurate plotting • Defect imaging

Multiple scan patterns and merged data to show potential imaging techniques for defects.

Dalsze usprawnienia : ruch sondy i detekcja w czasie rzeczywistym 2

Figure shows sectorial plans in the volume. Each slice presents a section of the defect at a different position. Such slices compare to metallographic multiple slices during defect sizing and characterization.

Multiple scan patterns and merged data to show potential imaging techniques for defects.

Obrazy cd 1

Multiangle inspection of a calibration block with stacked side-drilled holes. Left: inspection setup; right: ultrasound display—sectorial scan.

Obrazy cd 2

Example of UT range selection and sweep range for a crack detection and sizing with skip angles. Top: principle and UT range setting; bottom: OmniScan results for a fatigue crack of 8 mm height

Obrazy cd 3

Example of UT sweep range for a crack detection by two angles at difference >10 o Left: detection with 38.5°; right: detection with 60°. Remark the crack facets, detected also by skip, at 60°.

Obrazy cd 4

Example of UT data plotting (VC S-scan) of a crack into an isometricview of a turbine component.

Aparaty z głowicami mozaikowymi 1

The new model in the OmniScan® product line provides the advantage of phased array imaging for manual testing, while keeping all the benefits of a proven product

http://www.olympusndt.com/en/phasedarray/omniscanm/

The OmniScan MX is fully upgradable to any other model of the OmniScan series, allowing you to migrate to encoded inspection, data archiving, and automated UT inspection as your needs grow.

Aparaty z głowicami mozaikowymi 2

Olimpus

Aparat OmniScan MX PA 1

The OmniScan MX is fully upgradable to any other model of the OmniScan series, allowing you to migrate to encoded inspection, data archiving, and automated UT inspection as your needs grow.


OmniScan PA builds upon the OmniScan UT feature set and offers full-featured A-, B-, and C-scan displays.


OmniScan MX PAOmniScan MX PAOmniScan MX PA

OmniScan MX PAOmniScan MX PA

Aparat TomoScan FOCUS LT ™

• Full-featured PC-based software for data acquisition and analysis (TomoView ™)• Multiple channels or hased array probe configuration• Combined phased array and conventional UT configuration (TOFD + P/E)• File size of up to 1 GB• Fast 100Base-T data transfer (4 MB/s)• Configuration of up to 64:128• PRF up to 20 kHz • Real-time data compression and signal averaging• Interface to external motor controller and scanners.

Wykorzystanie głowic mozaikowych

Special Phased Array Applications forPipeline Girth Weld Inspections

Schematic showing zones on a CRC-Evans weld profile, and ultrasonic beams from a phased array probe.

Special Phased Array Applications forPipeline Girth Weld Inspections

http://www.ndt.net/article/ecndt2006/topic~39.htm

ECNDT 2006 - Fr.1.1.1

Michael MOLES, Olympus NDT Canada, Toronto, Canada

Simon LABBÉ, Olympus NDT Canada, Québec City, Canada

http://www.ndt.net/article/ecndt2006/topic~39.htm

Special Phased Array Applications forpipeline Girth Weld Inspections

Small diameter scanner.


Software display showing defect location, length and position.

Standard ASTM strip chart display with additional B-scan for interpretation. Figure shows a scan with an additional B-scan image; in this instance, it clarifies what looks like two defects as the same defect seen from both sides.


Portable phased array instrument for tie-ins and repairs, performing a linear scan on a weld.

Ultrasonic Phased Array Inspection of Turbine Components

ECNDT 2006 - Th.2.6.2 http://www.ndt.net/article/ecndt2006/topics~1.htm

Waheed A. ABBASI, Michael F. FAIR, SIEMENS Power Generation, Pittsburgh, USA

http://www.ndt.net/article/ecndt2006/topics~1.htm












Focal law simulation on a disc bore.Focal law simulation on a blade attachment.

Method musts include the modeling of the inspection component geometry and Phased Arrays to develop accurate control (focal) laws. In addition, the methods must include means of determining the behavior of the incident beam as well as the behavior of the reflected beam.


Focal law simulation on a disc bore.Focal law simulation on a blade attachment.

EDM notches were placed at the critical inspection areas and verification of the phased array focal laws for the particular style blade attachment were documented, as illustrated in Figure. The phased array focal laws, wedge design, and wedge positioning were confirmed.


Figure shows a display from a curved side entry blade attachment. The illustration on the left shows a section of the scan with the geometry from the blade attachment and an indication in the bottom serration, while the illustration on the right shows an overlay of the geometry and indication on the blade attachment.


Phased Array sound can be directed over a large area of the disc bore from a single position, however, much of the coverage is not useful detecting a crack. The model can determine the most effective “positions”.

Two nuclear LP discs with artificial flaws were manufactured to confirm the phased array transducer design, wedge design and coverage; one of the discs is illustrated in Figure 10. The two discs selected represent the most complex conditions for ultrasonic examination found in the Westinghouse disc design due to thickness (long metal paths) and geometry.


Figure shows a phased array scan (on left) and the phased array model (on right) of a Westinghouse LP disc. The phased array scan is inspecting a region on the disc bore that would require 6 conventional wedges as compared to one wedge for the phased array scan..


Conclussions• Phased array ultrasonic methods have been developed for the

inspection of various turbine components, specifically the blade attachments of turbine discs and the bores of turbine discs.

• These methods offer significant improvements over the conventional ultrasonic inspections and provide significant savings in time and cost.

• These methods are based on a sound development cycle where the inspection technique is developed, verified, and tested to prove its validity and worthiness for field use.

• It should be noted that for a reliable inspection it is imperative that the thorough development cycle of part geometry modeling (especially for complex geometries), optimum transducer design, accurate focal law calculation, and beam characterization be followed. Failing to follow this process can result in an inadequate inspection.

Badania ultradźwiękowe wielogłowicowe elementów konstrukcji Bolesław AUGUSTYNIAK.

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