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超声相控阵对缺陷大小的评估 韩向文

崇能电力. 超声相控阵对缺陷大小的评估 韩向文. 崇能电力. 概述. 介绍 常规超声和相控阵的声波形成 相控阵探头的参数设定 Design Parameters of Phased-Array Probes 声束聚焦 Beam Focusing 声束延时 Beam Steering 电子扫描 Electronical (Linear) Scanning 阵列分析. 介绍. 相控阵技术是电子改变超声探头的特性

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超声相控阵对缺陷大小的评估 韩向文

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  1. 崇能电力 超声相控阵对缺陷大小的评估 韩向文 . 我们提供的是解决方案

  2. 崇能电力 . 我们提供的是解决方案

  3. 概述 • 介绍 • 常规超声和相控阵的声波形成 • 相控阵探头的参数设定Design Parameters of Phased-Array Probes • 声束聚焦Beam Focusing • 声束延时Beam Steering • 电子扫描Electronical (Linear) Scanning • 阵列分析

  4. 介绍 • 相控阵技术是电子改变超声探头的特性 • Phased-array technology is the ability to modify electronicallythe acoustic probe characteristics • 电子延时技术改变阵列探头里面每一个晶片的激发和接收信号的时间延时来改变探头特性 Probe modifications are performed by introducing time shifts in the signals sent to (pulse) and received from (echo) individual elements of an array probe. • 任何UT技术都可以引进阵列探头技术进行缺陷的检测和大小评估 Any UT technique for flaw detection and sizing can be applied using phased-array probes.

  5. 延时Delay 触发脉冲Excitation pulse 晶片Crystal 契块Wedge B C A 材料Material B C A 位置Location 前沿波Wave front 常规波束的形成 • 常规超声探头是利用波束延时(发射) : • 惠更斯原理产生波束 • 契块的角度造成波束的延时，从而产生一定的发射角

  6. Delay Received signal Crystal Wedge C A B Material B C A Location S 常规超声波 • 常规超声探头利用波束延时 (接收) : • 惠更斯原理造成在契块产生声束 • 角度砌块产生接收延迟，因此只有一定相位的波束才会在晶片中产生有用的干涉

  7. Delay Time Focal law Wave front Element 相控阵波束 • 相控阵探头造成的波束延时 (发射) : • 惠更斯原理产生波束 • 电子延时造成波束的延时，从而产生一定的发射角

  8. 相控阵波束 S • 相控阵超声探头利用波束延时 (接收) : • 接收过程电子延时一定的时间 • 经过一系列电子处理（聚焦法则），使一定相位的信号安全的同时达到

  9. 相控阵波束 相控阵信号处理过程

  10. 相控阵探头的设计 • 线扫描阵列探头 a linear array (1D) is basically a long conventional probe … • 分割成每一小块，可以分别同时激发或单独激发 cut in many small elements, that can be individually excited

  11. 激发方向Active Plane p 固定方向Passive Plane A H 相控阵探头参数设定 • 频率Frequency (f), 波长wavelength () • 晶片数Number of elements (n) • 激发孔径Active aperture (A) • 孔径宽度Passive aperture (H) • 晶片宽度Element width (e) • 晶片间距Pitch (p)

  12. Wedge (vw) inc h1  x1 ref 相控阵探头的设计 契块参数 • 声速Velocity in wedge (vw) • 角度Wedge angle () • 第一晶片高度Height first element (h1) • 第一晶片前沿Offset first element (x1)

  13. 波束聚焦

  14. 波束聚焦 • 声波能量聚焦到一个小点 Is the capability to converge the acoustic energy into a small focal spot • 一个探头声波能量聚焦到不同的深度 Allows for focusing at several depths, using a single probe

  15. 波束聚焦 • 对称聚焦法则 Symmetrical (e.g. parabolic) focal laws(time delay vs. element position) • 只能在近场聚焦 Is limited to near-field only • 1D探头只能在波动面聚焦 Can only performed in the steering plane, when using a 1D-array

  16. 波束聚焦 不聚焦波束 • 近场距离和扩散角是由探头长度A 和波长决定 • 近场 • 扩散角 (half angle , at –6 dB ) • 波束宽度 (at depth z)

  17. 波束聚焦 聚焦波束FOCUSED BEAM • 聚焦系数Focusing coefficient (K) is defined as where F : focal distance N : near-field • 波束宽度是发射面聚焦距离决定Beam dimension (dst) in steering plane at focal distance is given by:

  18. 波束产生

  19. 波束产生 • 阵列探头能够修改波束的散射角度 Is the capability to modify the refracted angle of the beam generated by the array probe. • 单探头进行多角度检测 Allows for multiple angle inspections, using a single probe

  20. Beam Steering • Applies asymmetrical (e.g. linear) focal laws • Can only be performed in steering plane,when using 1D-arrays • Can generate both L (compression) and SV (shear vertical) waves, using a single probe

  21. Beam Steering • Steering capability is related to the width of an individual element of the array • Maximum steering angle (at –6 dB), given by • Steering range can be modified using an angled wedge

  22. Electronical (Linear) Scanning

  23. Electronical (Linear) Scanning • Is the ability to move the acoustic beamalong the axis of the array without any mechanical movement. • The beam movement is performed by time multiplexing of the active elements • Scanning extent limited by : • number of elements in array • number of “channels” in acquisition system

  24. Combined Beam Processing • The phased array technique allows for almost any combination of processing capabilities : • focusing + steering • linear scanning + steering • … • And be combined with any mechanical movement of the array probe, to obtain appropriate volumetric coverage of the inspection zone

  25. Combined Beam Processing

  26. Major Advantages of UT Phased-Array Technology • Improvement of inspection capability : • Optimized focusing • Optimized beam angle • Reduction of inspection time : • Simultaneous generation of multiple beams • One-line scan + sector scan/linear scan

  27. 缺陷分析和评估 Turn On or Off overlays linked to the thickness settings Overlay: First ½ skip Second ½ skip First full skip Reference at 80%

  28. PGM 探头的选择 • Scan Type: Sectorial Probe active elements

  29. PGM 探头的选择 • Scan Type: Linear

  30. 缺陷深度的测量 • S-Scan: (ruler in true depth) Ultrasound path (true depth) Probe axis

  31. 腐蚀测厚

  32. 相控阵对螺栓的检测

  33. 横向裂纹的检测

  34. 凹凸面材料的检测

  35. 水冷壁环向裂纹的检测

  36. Mechanical movement Phased array probe Penetration (Inconel 600) J-Weld (Alloy 182) Vessel head (Carbon steel) Typical defect orientations J焊缝的检测

  37. Thanks! 我们提供的是解决方案

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