Ultrasonic Detection of Fiber Orientation in Composite Laminates for Use of Vehicular Structures

2005 ◽  
Vol 297-300 ◽  
pp. 2109-2114
Author(s):  
Je Woong Park ◽  
Kwang Hee Im ◽  
David K. Hsu ◽  
Seung Woo Na ◽  
Young Nam Kim ◽  
...  
Keyword(s):  
Fiber Orientation ◽  
Composite Laminates ◽  
Azimuthal Angle ◽  
Normal Incidence ◽  
Test Results ◽  
Ultrasonic Signals ◽  
Fiber Placement ◽  
Reinforced Plastics ◽  
Vector Decomposition ◽  
Optical Test

The layup of a CFRP (carbon-fiber reinforced plastics) composite laminates affects the properties of the laminate, including stiffness, strength and thermal behavior. It is very important to detect ply error before the laminate is cured for both manual procedure and fiber placement procedure. An ultrasonic technique would be very beneficial, which could be used to test the part after and before curing laminates and requires less time than the optical test. Also cross-polarized scan is very sensitive to the layup errors and ply misorientations. Scanners were set out for different measurement modalities for acquiring ultrasonic signals as a function of in-plane azimuthal angle. Firstly, a manual scanner was built for making transmission measurements using a pair of normal-incidence shear wave transducers to find the effect of fiber misorientations of composite laminates. Also a method for nondestructively determining the ply layup in a composite laminate is presented. The method employs a normal-incidence longitudinal ultrasound to perform C-scan of ply interfaces of the laminate. And a ply-by-ply vector decomposition model has been utilized for evaluating layup errors in composite laminates fabricated from unidirectional plies. Test results between after and before curing laminates with model data were compared for a fiber orientation of the laminates.

Influence of Ultrasonic Shear Wave on Defect Angles of Stacking Using CFRP Composite Laminates

2006 ◽  
Vol 306-308 ◽  
pp. 787-792
Author(s):  
Je Woong Park ◽  
Sun Kyu Kim ◽  
Young Nam Kim ◽  
In Young Yang ◽  
David K. Hsu ◽  
...  
Keyword(s):  
Shear Wave ◽  
Composite Laminates ◽  
Azimuthal Angle ◽  
Normal Incidence ◽  
Cfrp Laminates ◽  
Fiber Placement ◽  
Decomposition Model ◽  
Vector Decomposition ◽  
Optical Test ◽  
Cfrp Composite

Because the layup of composite laminates influences there properties, the strength of composites depends on layup sequence of CFRP laminates. It is very important to detect ply error before the laminate is cured for both manual procedure and fiber placement procedure. An ultrasonic technique would be very beneficial, which could be used to test the part after and before curing laminates and requires less time than the optical test. Scanners were set out for different measurement modalities for acquiring ultrasonic signals as a function of in-plane azimuthal angle. The first motorized scanner was utilized for making transmission measurements using a pair of normal-incidence shear wave transducers. A scanner was built for the acousto-ultrasonic configuration using contact transducers. And a ply-by-ply vector decomposition model has been utilized for evaluating layup errors in composite laminates fabricated from unidirectional plies. We have compared the test results with model data. It is found that high probability shows between experimentations and the decomposition model in characterizing cured and uncured laminates with defect angles.

Feasibility and Application on Ultrasonic-Polarized Shear Wave of Fiber Orientation Detection in Orthotropic Composite Laminates

2006 ◽  
Vol 324-325 ◽  
pp. 911-914
Author(s):  
Je Woong Park ◽  
Kwang Hee Im ◽  
David K. Hsu ◽  
Sun Kyu Kim ◽  
In Young Yang
Keyword(s):  
Shear Wave ◽  
Fiber Orientation ◽  
Composite Laminates ◽  
Isosceles Triangle ◽  
Test Results ◽  
Model Data ◽  
Orientation Error ◽  
Orthotropic Composite ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics

It is very important to detect fiber orientation error in orthotropic composite laminates because the layup of a CFRP (carbon-fiber reinforced plastics) composite laminates affects the properties of the laminate, including stiffness, strength and thermal behavior. In this study, an investigation of shear wave ultrasonic technique was carried out in order to detect stacking orientation error for the orthotropic composite laminates. During testing, the most significant problem is that the couplant conditions do not remain the same because of changing the viscosity of the couplant. Therefore, the design and use of a shear wave transducers would greatly aid in alleviating the couplant problem. A pyramid with an isosceles triangle with two 45o was made of aluminum to generate shear waves using two longitudinal transducers based on ultrasonicpolarized mechanism. Also, the signal splitter was connected to the pulser jack on the pulser/receiver and to the longitudinal transducers which were mounted with mineral oil. The shear transducer was mounted on the bottom as a receiver with burnt honey. It is found that the shear wave was generated at a maximum and a minimum based on the ultrasonic-polarized mechanism. Finally, test results with model data were compared for a fiber orientation of the laminates.

Non-Contact and Contact Ultrasonic Detection of Fiber Orientation in Orthotropic Composite Laminates

2006 ◽  
Vol 324-325 ◽  
pp. 419-422
Author(s):  
In Young Yang ◽  
Uk Heo ◽  
Kil Sung Lee ◽  
Je Woong Park ◽  
Young Sub Kweon ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Lamb Waves ◽  
Specular Reflection ◽  
Azimuthal Angle ◽  
Normal Incidence ◽  
Fiber Direction ◽  
Orthotropic Composite ◽  
Shaped Tube ◽  
Optical Test ◽  
Conventional Ultrasound

Since layup orientation of the laminates greatly influences its properties, an NDE technique for layup orientation determination would be very beneficial. It is desirable to perform contact-less nondestructive evaluation to assess material properties and defects of composites because of permeation of coupling medium such as water. An ultrasonic technique would be very useful, which could be used to test the part after and before curing laminates and requires less time than the optical test. First of all, conventional ultrasonic experimentations were conducted using water as a transmitting medium. In contrast, air-coupled ultrasound is non-contact and has clear advantages over water-coupled testing. Therefore ultrasonic systems for air-coupled and conventional ultrasound were set out for different measurement modalities for acquiring ultrasonic signals as a function of in-plane azimuthal angle. Firstly, a manual scanner was built for making transmission measurements using a pair of normal-incidence shear wave transducers to find the effect of fiber misorientations of orthotropic composite laminates. With the transmitter and receiver on the same side of a laminates, Lamb waves were generated and used for the amplitude magnitude. As a result, it was confirmed that the influence of fiber direction in the laminates could be detected by the non-contacting or contacting inspection from one-side and the detectability was improved by using shaped tube for reducing the specular reflection on transmitting. Furthermore, a vector decomposition model was utilized for lay-up error of the orthotropic laminates. Finally, aircoupled results well corresponded somewhat to those of contact ultrasonic examination in the orthotropic laminates.

Nondestructive Determination of Ply-Layup Error in Cured/Uncured CF/Epoxy Composites

2006 ◽  
Vol 321-323 ◽  
pp. 893-896
Author(s):  
Young Sub Kweon ◽  
Kwang Hee Im ◽  
David K. Hsu ◽  
Dong Fei ◽  
Seung Woo Ra ◽  
...  
Keyword(s):  
Fiber Orientation ◽  
Composite Laminates ◽  
Composite Laminate ◽  
Epoxy Composite ◽  
Normal Incidence ◽  
Epoxy Composites ◽  
Automated System ◽  
Nondestructive Technique ◽  
Orientation Information

A nondestructive technique would be very beneficial, which could be used to test the part before (uncured) and after curing CF/Epoxy. A new method for nondestructively determining the ply layup in a composite laminate is presented. The method employs a normal-incidence longitudinal ultrasound to perform C-scan of ply interfaces of the laminate, and extracts fiber orientation information from the ultrasonic reflection in the laminate. Using two-dimensional spatial Fourier transform, interface C-scan images were transformed into quantitatively angular distribution plots to show the fiber orientation information therein and to determine the orientation of the ply. In order to develop these methods into practical inspection tools, an automated system using a motor has been developed for different measurement modalities for acquiring ultrasonic effects of ply-layup error. Therefore, it is found that the efficiency of developed system shows between the practical testing and model in characterizing cured/uncured ply-layup error of the laminates. A C-scan image of a ply interface seem to have the ply-layup error information of the two neighboring plies of CF/Epoxy composite laminates.

On Feasibility of Ply-Layup Orientation in CF/Epoxy Composite Laminates Using Rayleigh Probes

2007 ◽  
Vol 29-30 ◽  
pp. 299-302
Author(s):  
Jae Woung Park ◽  
Kwang Hee Im ◽  
David K. Hsu ◽  
Uk Heo ◽  
K.S Lee ◽  
...  
Keyword(s):  
Fiber Orientation ◽  
Composite Laminates ◽  
Composite Laminate ◽  
Epoxy Composite ◽  
Normal Incidence ◽  
The Other ◽  
Two Dimensional ◽  
Nondestructive Technique ◽  
Orientation Information ◽  
The One

A nondestructive technique would be very beneficial, which could be used to test the CF/Epoxy composite laminates. A new method for nondestructively determining the ply layup in a composite laminate is presented. A one-sided pitch-catch setup was used in the detection and evaluation of flaws and material anomalies in the composite laminates. Two Rayleigh wave transducers were joined head-to-head and used in the pitch-catch mode on the surface of the composites. The pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave to subtle flaw conditions in the composite. Also the other method employs a normal-incidence longitudinal ultrasound to perform C-scan of ply interfaces of the laminate, and extracts fiber orientation information from the ultrasonic reflection in the laminate. Using two-dimensional spatial Fourier transform, interface C-scan images were transformed into quantitatively angular distribution plots to show the fiber orientation information therein and to determine the orientation of the ply. Therefore, it is found that the efficiency of developed system shows between the one-sided pitch-catch testing and C-scan images in characterizing ply-layup orientation of the laminates.

A Nondestructive Study on Fiber Layup and Porosity Level in CFRP Composite Laminates Using Ultrasonic Pitch-Catch Method

2010 ◽  
Vol 123-125 ◽  
pp. 815-818
Author(s):  
Kwang Hee Im ◽  
Je Woong Park ◽  
David K. Hsu ◽  
Sun Kyu Kim ◽  
Young Tae Cho ◽  
...  
Keyword(s):  
Image Processing ◽  
Composite Laminates ◽  
Normal Incidence ◽  
Test Sample ◽  
Separation Distance ◽  
Processing Method ◽  
Nondestructive Technique ◽  
Porosity Level ◽  
Image Processing Method ◽  
Reinforced Plastics

A nondestructive technique would be very useful for evaluating the CF/Epoxy composite laminates. It is found that a pitch-catch signal was more sensitive than normal incidence backwall echo of longitudinal wave to subtle flaw conditions in the composites (damages, fiber orientation, low level porosity, ply waviness, and cracks). The depth of the sampling volume where the pitch-catch signal came from was relatively shallow with the head-to-head miniature Rayleigh probes, but the depth can be increased by increasing the separation distance of the transmitting and receiving probes. Also, a method was utilized to determine the porosity content of a composite lay-up by processing micrograph images of the laminate. The porosity content of a composite structure is critical to the overall strength and performance of the structure. The image processing method developed utilizes a free software package to process micrograph images of the test sample. The results from the image processing method are compared with existing data. Beam profile was characterized in unidirectional CFRP (Carbon fiber reinforced plastics) with using pitch-catch Rayleigh probes and the one-sided and two-side pitch-catch technique was utilized to produce C-scan images with the aid of the automatic scanner. Also, it is confirmed that the pitch-catch ultrasonic signal was corresponding with simulated results assuming in unidirectional CFRP composites.

scholarly journals Experimental Investigation on the Influence of Fiber Path Curvature on the Mechanical Properties of Composites

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2602
Author(s):  
Huaqiao Wang ◽  
Jihong Chen ◽  
Zhichao Fan ◽  
Jun Xiao ◽  
Xianfeng Wang
Keyword(s):  
Tensile Strength ◽  
Path Planning ◽  
Composite Laminates ◽  
Bending Strength ◽  
High Strength ◽  
Bending Test ◽  
Fiber Placement ◽  
Automated Fiber Placement ◽  
Fiber Path ◽  
Path Curvature

Automated fiber placement (AFP) has been widely used as an advanced manufacturing technology for large and complex composite parts and the trajectory planning of the laying path is the primary task of AFP technology. Proposed in this paper is an experimental study on the effect of several different path planning placements on the mechanical behavior of laminated materials. The prepreg selected for the experiment was high-strength toughened epoxy resin T300 carbon fiber prepreg UH3033-150. The composite laminates with variable angles were prepared by an eight-tow seven-axis linkage laying machine. After the curing process, the composite laminates were conducted by tensile and bending test separately. The test results show that there exists an optimal planning path among these for which the tensile strength of the laminated specimens decreases slightly by only 3.889%, while the bending strength increases greatly by 16.68%. It can be found that for the specific planning path placement, the bending strength of the composite laminates is significantly improved regardless of the little difference in tensile strength, which shows the importance of path planning and this may be used as a guideline for future AFP process.

THE EFFECT OF LAMINATION SCHEME AND ANGLE VARIATIONS TO THE DISPLACEMENTS AND FAILURE BEHAVIOUR OF COMPOSITE LAMINATE

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Azizul Hakim Samsudin ◽  
Jamaluddin Mahmud
Keyword(s):  
Fiber Orientation ◽  
Composite Laminates ◽  
Finite Element Modelling ◽  
Composite Laminate ◽  
Maximum Stress ◽  
Failure Load ◽  
Failure Criteria ◽  
Stress Theory ◽  
Failure Behaviour ◽  
Failure Index

This paper aims to investigate the effect of lamination scheme and angle variations to the displacements and failure behaviour of composite laminate. Finite element modelling and analysis of symmetric, anti-symmetric and angle-ply Graphite/ Epoxy laminate with various angles of fiber orientation subjected to uniaxial tension are performed. Maximum Stress Theory and Tsai-Wu Failure Criteria are employed to determine the failure load (failure index = 1). Prior to that, convergence analysis and numerical validation are carried out. Displacements and failure behaviour of the composite laminates (symmetric, anti-symmetric and angle ply) are analysed. The failure curves (FPF and LPF) for both theories (Maximum Stress Theory and Tsai-Wu) are plotted and found to be very close to each other. Therefore, it can be concluded that the current study is useful and significant to the displacements and failure behaviour of composite laminate.

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