开发用于表征厚钢筋混凝土构件的先进超声相控阵
Laurence Jacobs, Georgia Institute of Technology
Kim Kurtis, Jin-Yeon Kim, Prasanth Alapati, Max May (Georgia Tech)
Jianmin Qu, Xiang Gao (Tufts University)
Project Vision
开发超声波相控阵设备，该设备使用波混合和非线性声学技术来定量表征和成像厚钢筋混凝土构件中的微尺度（１００ μｍ）损伤。
Total Project Cost:
$0.87M
Length
24 mo.
The Concept
‣
通过开发超声波相控阵设备来表征和量化整个组件厚度的微尺度损伤，提高混凝土的耐久性
‣
将超声波相控阵技术与非线性波混合和混凝土材料建模相结合，实现钢筋混凝土构件的“医疗质量”成像
The Team
？来自佐治亚理工学院 （３） 和塔夫茨大学 （１） 的四位教职联合 ＰＩ 团队
？Ｌａｕｒｅｎｃｅ Ｊａｃｏｂｓ：线性和非线性超声，混凝土的无损检测
？Ｋｉｍ Ｋｕｒｔｉｓ：了解水泥基材料的新兴方法
？Ｊｉｎ－Ｙｅｏｎ Ｋｉｍ：ＮＤＥ、相控阵的测量和建模方法
？Ｊｉａｎｍｉｎ Ｑｕ：混凝土的超声与微观力学
？Ｊａｃｏｂｓ ａｎｄ Ｋｉｍ：相控阵器件的开发； 材料建模
？Ｑｕ：优化混波方案的计算建模
？Ｋｕｒｔｉｓ：已知损伤样本的材料建模和开发
2
Project Objectives
＊天线）传感器生成正向混合波的能力
＊前向波混合的第一年通过／不通过演示，以检测和表征 ３－Ｄ 中的微尺度（大约 １．０ 毫米）损坏，扫描时间低于
３０ 分钟，用于前向传播的体积为 ５００ 立方英寸（１０ ／１５／２０２０）
＊团队将开发和商业化能够在 １０－１００ ｋＨｚ 范围内进行非线性混波的相控阵
＊努力确定最佳的第一个商业应用：通过厚度的微尺度损伤图像在哪里对通知和优先维护和维修策略至关重要？
3
动机：非线性瑞利波跟踪 ＡＳＲ 损坏
＊应用非线性瑞利表面波来表征 ＡＳＲ 损伤（团队以前的工作）
＊ＥＰＲＩ 板和 ＯＲＮＬ／ＵＴＫ 板的测量
Kim et al, JNDE 2017 and Con Bldg Mat, 2018
4
动机：波混合基础
Shear wave
transducer
uR ( y , t )
Vs_new
uT ( y , t )
x,u
Resonant
Condition
Resonant
Shear Wave
Vs
Vl
uL ( y , t )
y,v
y0
L
2cLThickness d

T cL  cT
A
uR ( y , t )  A cos[R (t 
Longitudinal wave
transducer
signal
T ( y0 )U ( y0 )V ( y0 )T2l
y
)]
cT
2cT (cL  cT )
cL  cT
R 
T
cL  cT
6
Model for wave mixing: Polarization analysis
In-plane polarization:
2cos Δ𝜃
2−1
= cos(2Δ𝜃)
Out-of-plane polarization:
7
Model for wave mixing: Beam steering with an array
• Typical side lobes with peak side lobes
•
•
•
•
•
much smaller than main lobe
Phased arrays are designed for fixed
frequency, nonlinear wave mixing
techniques with varying frequencies would
add additional design constraints
Array for beam steering only, not detection
Normalized pressure for beam steering at 𝜃
_𝑠=30°, with parameters: 𝛿_𝑥=25𝑚𝑚, 𝑁=8,
𝑓=80𝑘𝐻𝑧, 𝑐_𝑇=2702 𝑚𝑠^(−1), 𝜆_𝑙=3.38𝑐𝑚
Main lobe at 30°
Grating lobe appears due to spatial aliasing
for 𝜆_𝑙/2<𝛿_𝑥 at −58°
8
Model for wave mixing: Maximum steering angle 𝜃𝑠
• Steering angles of both arrays are limited depedent on their
input frequency
• Frequency ratio is fixed by condition at mixing points
• Lower frequencies degrade steering ability
Model for wave mixing: Possible configurations
Traditional configuration
9
Arrays on wedges
0
Computational results: Amplitude of mixing wave at receiver
Signal Receiver
𝜙
𝑑3
𝑑1
1
Δ𝜃
h
𝑑2
𝐿 = 𝜉ℎ
Array Transducer #1
2
Array Transducer #2
Amplitude with attenuation
A( ) 
U1U 2
2






cos
    1  exp(1d1   2 d 2   3 d3 )

1 2  T1
T2
2
CL
2

1 1   1
  2  m
  3  2 m
2
cos( ) 



1


,


,


 

T1
T2


2    



Frequency(MHz)
0.1
0.08
0.05
0.03
0.01
Attenuation (dB)
73.2
58.5
36.6
22
7.3
Computational results: Polarization choices
Resonant mixed waves
SV (1 )  SV (2 )  L( )

1  cos  
SH (1 )  SH (2 )  L(  ) 1  cos  
L(1 )  SV (2 )  L( )

  1 2
cos
2

2
2
1  cos  
SV – Transversely Polarized Shear Wave
SH – Horizontally Polarized Shear Wave
L – Longitudinal Wave
  cL cT  2
2
1
 1
 1
 
 1
 1
1
 1
 1
 
 1
 1
1


 1
2
k   k1  k 2
 k c
k1
k   k1  k 2

k2
0
Computational results: Effects of attenuation
SV (1 )  SV (2 )  L(1  2 )
dB
Measurement results: Array equipment
Ultrasonic array system
Interface
Cables
Array Antennae
(32 elements x2)
Possible setup on concrete slab
Array
Controller
Surrogate Concrete Slab
13
Measurement results: Samples
Samples: mini mortar and concrete blocks 15x15x40 cm^3
Concrete
Array Antennae
Mortar
November 6, 2020
Insert Presentation Name
14
Measurement results: Single-sided inspection using the reflection of the
mixed wave off the bottom surface
Detect reflection of mixed wave off of
the bottom surface
Phased Array 1
Non-contact
receiver
Primary
wave
Phased Array 2
Secondary
wave
Primary
wave
A
Concrete block
B
Inspection
volume
Bottom Surface
Is the amplitude of the nonlinear mixed signal
large enough to be detected after reflection from
the bottom surface?
Measurement results: Reference mixing in the mini concrete block
1
2
3
4
Changing the
separation
distance
between
transducers.
Measurement results: Reference mixing in the mini concrete block
Bounce mixed ultrasonic signal off bottom surface for single side operation
@ spot #3 (10 cm from the top surface)
nonlinear mixing signal
Multiply reflected signals
Original
Window where the
nonlinear mixing
signal is expected,
based on time of
flight
Signal processing
(windowing, band-pass filtering)
Filtered
Frequency Spectrum
Measurement results: Reference mixing in the mini concrete block
Expected
Measurement results: Sketch of the concrete block showing 4 types of embedded
microscale damage
A
B
C
5″
Mechanical
Recycled
damage
aggregate
5″
3″
3″
4″
12″
6″
Cross section at
AA1
4″
4.5″
3″
Recycled
Mechanical
aggregate 4″
damage
6″
4″
5 ft
Cross section at
AA1
4″
4.5″
ASR
3″
4″
6″
1-3″
4″
14″
4″
C1
D1
Cross section at
CC1
Cross section at
DD1
5″
5″
4.5″
4.5″
12″
Thermal
Fire
damage
4″
B1
5″
12″
5″
3″
4″
A1
5″
Entrained
air voids
ASR
D
4.5″
Entrained
air voids
3″
4″
5″
4.5″
4.5″
Fire
Thermal
damage
damage
3″
4″
0
19
12″
12″
12″
12″
4.5″
Challenges
‣ One challenge is the inherent physics of the problem: high attenuation due to
scattering from the aggregate and material interfaces in the ultrasonic frequency
range
‣ A second challenge is lack of array (antennae) manufacturers in the required
frequency range: this application is too low for medical (and metallic material)
applications, and too high for near field geophysics applications
‣ A third challenge will be that many owners take the “ignorance is bliss” approach.
‣ Wave mixing and nonlinear ultrasound allow for a lower frequency approach and
still enable imaging at the microscale level
‣ Once the device has been developed and its accuracy demonstrated, it will be
critical to find the right field demonstration application
Potential Partnerships
‣ Team with concrete NDT suppliers. EPRI and Georgia DOT. Any capabilities to
offer other teams, or potential collaborations with other teams?
November 6, 2020
Insert Presentation Name
21
Summary Slide
‣ Combine ultrasonic phased array technology with an understanding of nonlinear
wave propagation in heterogeneous media and concrete material modeling to
enable “medical quality” imaging and characterization of thick reinforced concrete
components
‣ Nonlinear mixing techniques are not wavelength dependent, thus enabling
characterization of microscale damage (much smaller than inherent
microstructure) in heterogenous concrete material
‣ Team has expertise NDE of concrete, nonlinear wave mixing, phased arrays and
material modeling of concrete
‣ Develop ultrasonic phased array device that uses wave mixing and nonlinear
acoustic techniques to quantitatively characterize microscale damage in thick,
reinforced concrete components
November 6, 2020
Insert Presentation Name
22
23
Spares
24
Project Vision
Computational results: Choices of incident wave pairs
   k1  k 2 c

k  k1  k 2
Forward Mixing
k1
1  k1 c
k   k1  k 2
   k1  k 2 c

k2
2  k 2 c
Backwards Mixing
0
Computational results: Choices of incident wave pairs