Photo-Acoustic Based Non-Contact and Non-Destructive Evaluation for Detection of Damage Precursors in Composites

2018 ◽  
Author(s):  
Siqi Wang ◽  
Liangzhong Xiang ◽  
Yingtao Liu ◽  
Hong Liu
Keyword(s):  
High Resolution ◽  
Imaging System ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Complex Load ◽  
Pull Out ◽  
Matrix Cracks ◽  
Non Destructive Evaluation ◽  
Cfrp Composites ◽  
Non Destructive

Damage precursor in composites can lead to large structural damages, such as delamination, in carbon fiber reinforced plastic (CFRP) composites due to complex load conditions and environmental effects. In addition, multiple types of damage precursors including micro-scale matrix cracks, fiber pull-out from matrix, and fiber breakages, are extremely difficult to detect due to the limitation of resolution of current non-destructive evaluation (NDE) technologies. This paper presents a photo-acoustic based non-contact NDE system for the detection of damage precursors with extremely high resolution up to one hundred micrometers. This system consists of three major components: picoseconds pulsed laser based ultrasonic actuator, ultrasound receiver, and data processing and computing subsystem. Picoseconds pulsed laser is used to generate ultrasonic propagations in composites during the NDE process, and the ultrasound signals are recorded by the ultrasound receiver. Three-dimensional microstructure of the individual composites grid within the composite is able to be reconstructed for further analysis. The size and position of the damage precursors are evaluated with high accuracy up to 100 μm. The experimental results demonstrate that this imaging system is able to provide a novel non-contact approach with extremely high resolution for damage detection of CFRP composites. In addition, the developed NDE system has a wide industrial application in aerospace, automobile, civil, mechanical, and other key industries.

scholarly journals A simple, high-resolution, non-destructive method for determining the spatial gradient of the elastic modulus of insect cuticle

2018 ◽  
Vol 15 (145) ◽  
pp. 20180312 ◽  
Author(s):  
S h. Eshghi ◽  
M. Jafarpour ◽  
A. Darvizeh ◽  
S. N. Gorb ◽  
H. Rajabi
Keyword(s):  
Elastic Modulus ◽  
High Resolution ◽  
Three Dimensional ◽  
Insect Cuticle ◽  
Spatial Gradient ◽  
Engineering Systems ◽  
Small Complex ◽  
Load Carrying ◽  
Using Data ◽  
Non Destructive

Nature has evolved structures with high load-carrying capacity and long-term durability. The principles underlying the functionality of such structures, if studied systematically, can inspire the design of more efficient engineering systems. An important step in this process is to characterize the material properties of the structure under investigation. However, direct mechanical measurements on small complex-shaped biological samples involve numerous technical challenges. To overcome these challenges, we developed a method for estimation of the elastic modulus of insect cuticle, the second most abundant biological composite in nature, through simple light microscopy. In brief, we established a quantitative link between the autofluorescence of different constituent materials of insect cuticle, and the resulting mechanical properties. This approach was verified using data on cuticular structures of three different insect species. The method presented in this study allows three-dimensional visualisation of the elastic modulus, which is impossible with any other available technique. This is especially important for precise finite-element modelling of cuticle, which is known to have spatially graded properties. Considering the simplicity, ease of implementation and high-resolution of the results, our method is a crucial step towards a better understanding of material–function relationships in insect cuticle, and can potentially be adapted for other graded biological materials.

scholarly journals Ultrahigh Resolution Pulsed Laser-Induced Photoacoustic Detection of Multi-Scale Damage in CFRP Composites

2020 ◽  
Vol 10 (6) ◽  
pp. 2106 ◽  
Author(s):  
Siqi Wang ◽  
Jesse Echeverry ◽  
Luis Trevisi ◽  
Kiana Prather ◽  
Liangzhong Xiang ◽  
...  
Keyword(s):  
Pulsed Laser ◽  
Projection Algorithm ◽  
Two Dimensional ◽  
High Frequency Ultrasound ◽  
Photoacoustic Detection ◽  
Ultrahigh Resolution ◽  
Multi Scale ◽  
Cfrp Composites ◽  
Macro Scale ◽  
Non Destructive

This paper presents a photoacoustic non-destructive evaluation (pNDE) system with an ultrahigh resolution for the detection of multi-scale damage in carbon fiber-reinforced plastic (CFRP) composites. The pNDE system consists of three main components: a picosecond pulsed laser-based ultrasonic actuator, an ultrasound receiver, and a data acquisition/computing subsystem. During the operation, high-frequency ultrasound is generated by pulsed laser and recorded by an ultrasound receiver. By implementing a two-dimensional back projection algorithm, pNDE images can be reconstructed from the recorded ultrasound signals to represent the embedded damage. Both potential macroscopic and microscopic damages, such as surface notches and delamination in CFRP, can be identified by examining the reconstructed pNDE images. Three ultrasonic presentation modes including A-scan, B-scan, and C-scan are employed to analyze the recorded signals for the representation of the detected micro-scale damage in two-dimensional and three-dimensional images with a high spatial resolution of up to 60 µm. Macro-scale delamination and transverse ply cracks are clearly visualized, identifying the edges of the damaged area. The results of the study demonstrate that the developed pNDE system provides a non-destructive and robust approach for multi-scale damage detection in composite materials.

A System for Computer-based Reconstruction of 3-Dimensional Structures from Serial Tissue Sections: an Application to the Study of Normal and Neoplastic Mammary Gland Biology

2001 ◽  
Vol 7 (S2) ◽  
pp. 964-965
Author(s):  
Rodrigo Fernandez-Gonzalez ◽  
Arthur Jones ◽  
Enrique Garcia-Rodriguez ◽  
Davis Knowles ◽  
Damir Sudar ◽  
...  
Keyword(s):  
Mammary Gland ◽  
High Resolution ◽  
Imaging System ◽  
Contextual Information ◽  
Three Dimensional ◽  
Tissue Level ◽  
Disease Heterogeneity ◽  
Tissue Sections ◽  
Virtual Reconstruction ◽  
Analytical Microscopy

Tissue heterogeneity and three-dimensionality are generally neglected by most traditional analytical microscopy methods in Biology. These often disregard contextual information important for understanding most biological systems. in breast cancer, which is a tissue level disease, heterogeneity and three dimensionality are at the very base of cancer initiation and clonal progression. Thus, a three dimensional quantitative system that allows low resolution virtual reconstruction of the mammary gland from serial sections, followed by high resolution cell-level reconstruction and quantitative analysis of the ductal epithelium emerges as an essential tool in studying the disease. We present here a distributed microscopic imaging system which allows acquiring and registering low magnification (1 pixel = 5 μm) conventional (bright field or fluorescence) images of entire tissue sections; then it allows tracing (in 3D) the ducts of the mammary gland from adjacent sections, to create a 3D virtual reconstruction of the gland; finally it allows revisiting areas of interest for high resolution (1 pixel = 0.5 μm) imaging and automatic analysis. We illustrate the use of the system for the reconstruction of a small volume of breast tissue.

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