A Broadband—Holography Imaging System for Nondestructive Evaluation

1987 ◽  
pp. 547-557
Author(s):  
G. Prokoph ◽  
H. Ermert ◽  
M. Kröning
Keyword(s):  
Nondestructive Evaluation ◽  
Imaging System

Dual-energy wave subtraction imaging for evaluation of barely visible impact damage with an ultrasonic propagation imaging system

2017 ◽  
Vol 29 (17) ◽  
pp. 3411-3425 ◽  
Author(s):  
Yunshil Choi ◽  
Jung-Ryul Lee
Keyword(s):  
Laser Beam ◽  
Nondestructive Evaluation ◽  
Composite Structures ◽  
Imaging System ◽  
Impact Damage ◽  
Dual Energy ◽  
Ultrasonic Waves ◽  
Excitation Energies ◽  
Ultrasonic Signals ◽  
Ultrasonic Propagation

Barely visible impact damage from low-velocity impacts have been studied as critical design factors of composite structures. In this article, a dual-energy wave subtraction algorithm using an ultrasonic propagation imaging system is proposed to evaluate barely visible impact damage as a strategy of fast in situ nondestructive evaluation or structural health monitoring (SHM). The ultrasonic propagation imaging system is a type of nondestructive evaluation or SHM system and is based on scanning laser-induced guided ultrasound and fixed sensors. The amplitude of ultrasonic signals generated by the ultrasonic propagation imaging system increases with the increasing energy of the laser beam. Two ultrasonic signals generated by different excitation energies of the laser beam can be equalized by multiplying a constant factor to one of them. Therefore, the residuals after subtraction of two signals may be close to zero. However, the two different energy induced signals in the damaged area will be nonzero due to the change in material conditions regarding the laser ultrasonic generation mechanism. The dual-energy wave subtraction algorithm eliminates most of the incident ultrasonic waves and amplifies anomalous waves. A composite wing skin including two barely visible impact damages as well as a composite sandwich panel, including a single barely visible impact damage, were inspected to validate the proposed algorithm.

Enhanced magneto-optic imaging system for nondestructive evaluation

2007 ◽  
Vol 40 (5) ◽  
pp. 374-377 ◽  
Author(s):  
Yu Hua Cheng ◽  
Zhao Fei Zhou ◽  
Gui Yun Tian
Keyword(s):  
Nondestructive Evaluation ◽  
Imaging System ◽  
Magneto Optic

Nondestructive Imaging of Packaged Microelectronics using Pulsed Terahertz Technology

2017 ◽  
Vol 2017 (1) ◽  
pp. 000709-000714
Author(s):  
Tyler Bowman ◽  
Magda El-Shenawee
Keyword(s):  
Nondestructive Evaluation ◽  
Imaging System ◽  
Incident Angle ◽  
Terahertz Imaging ◽  
Vertical Position ◽  
Power Mosfets ◽  
Additional Information ◽  
Size Number ◽  
Bond Wires ◽  
Nondestructive Imaging

Abstract This work presents the use of terahertz reflection imaging for nondestructive evaluation of packaged microelectronics. Power MOSFETs and SRAM devices are placed in a pulsed terahertz imaging system in the reflection mode with an incident angle of 30°. From the received signal at each point on the sample under test, the internal structure of the device can be clearly seen. For transistors, terahertz nondestructive imaging has been successful in determining die size and location as well as the bond wire size, number, and connections. High-pass frequency filters are utilized to enhance the image quality for viewing the bond wires. In addition, the terahertz B-scans are used to determine additional information including the vertical position of the bond wires and the die inside the packaged device. For the SRAM, the terahertz nondestructive imaging shows similar effectiveness in defining the layout of the metal connections inside the package and the wire positions. Thus terahertz imaging is shown to have a strong potential for nondestructive evaluation of these devices.

Robotic 3D SQUID imaging system for practical nondestructive evaluation applications

2005 ◽  
Vol 432 (3-4) ◽  
pp. 182-192 ◽  
Author(s):  
K. Isawa ◽  
S. Nakayama ◽  
M. Ikeda ◽  
S. Takagi ◽  
S. Tosaka ◽  
...  
Keyword(s):  
Nondestructive Evaluation ◽  
Imaging System
Sign in / Sign up

Export Citation Format

Share Document