Two Tiered Analysis of a CFRP Laminate Imbedded With Magnetostrictive Particles

2010 ◽  
Author(s):  
George Currie ◽  
Dustin Spayde ◽  
Oliver Myers
Keyword(s):  
Experimental Approach ◽  
Analytical Investigation ◽  
Experimental Investigations ◽  
Cfrp Laminate ◽  
Cfrp Laminates ◽  
Excitation Coil ◽  
Laminate Theory ◽  
Linear Sections ◽  
Strength And Stiffness ◽  
Fundamental Equations

The overall purpose of this research is to characterize the affects of imbedding magnetostrictive particles (MSP) in a CFRP laminate for the purpose of nondestructive evaluation. This paper details an investigation using an analytical and experimental approach. At the time of this publication, both the analytical and experimental investigations are in a preliminary stage and the results have not yet converged. The analytical investigation utilizes fundamental equations for the magnetomechanical properties of the MSP and classical laminate theory for the strength and stiffness of the CFRP laminate to obtain a model of the combination. It is assumed that the magnetomechanical relationship of the MSP layer is a function of the prestress acting on the layer. This relationship is nonlinear in nature but is broken down into a number of linear sections to facilitate analysis. This prestress acting on the MSP layer is a result of the CFRP laminate’s stiffness resisting the induced strain of the MSP layer. Classical laminate theory is used to obtain the value of the prestress as a function of this induced strain. As would be expected, this analysis becomes an iterative process. The induced strain is calculated based on a prestress level of zero. This strain is then used to calculate the amount of stress in the CFRP laminate which becomes the prestress value, and the process is repeated until convergence is reached. Unidirectional CFRP laminates are used in this analysis. The experimental approach involved testing a collection of composite beams imbedded with MSP using a scanner that surrounded the beams. The scanner was composed of an excitation coil and a sensing coil. A detailed schematic of the scanner is included in the paper showing the slide along which the scanner apparatus moved, and the sensing coil surrounded by the excitation coil. The samples used in this analysis were constructed from unidirectional prepreg carbon fiber with varying internal delaminations, ply orientations, and number of plies. A program was constructed that allowed the user to control the signal being output to the excitation coil as well as record data from the sensing coil. The results presented in this paper are not final and will be used to create a foundation for continuation of this research.

scholarly journals Bond between Concrete and Multi-Directional CFRP Laminates

2010 ◽  
Vol 133-134 ◽  
pp. 917-922 ◽  
Author(s):  
José Sena-Cruz ◽  
Joaquim Barros ◽  
Mário Coelho
Keyword(s):  
Carbon Fiber ◽  
Civil Engineering ◽  
Fiber Reinforced Polymers ◽  
Structural Elements ◽  
Engineering Applications ◽  
Carbon Fiber Reinforced Polymers ◽  
Reinforced Polymers ◽  
Cfrp Laminate ◽  
Cfrp Laminates ◽  
Pullout Tests

Recently, laminates of multi-directional carbon fiber reinforced polymers (MDL-CFRP) have been developed for Civil Engineering applications. A MDL-CFRP laminate has fibers in distinct directions that can be arranged in order to optimize stiffness and/or strength requisites. These laminates can be conceived in order to be fixed to structural elements with anchors, resulting high effective strengthening systems. To evaluate the strengthening potentialities of this type of laminates, pullout tests were carried out. The influence of the number of anchors, their geometric location and the applied pre-stress are analyzed. The present work describes the carried-out tests and presents and analyzes the most significant obtained results.

Reduction of Impact Noise at the Design Stage: A Specific Case Study

1972 ◽  
Vol 186 (1) ◽  
pp. 391-399
Author(s):  
M. A. Salter ◽  
B. Downs ◽  
G. R. Wray
Keyword(s):  
Experimental Approach ◽  
Design Stage ◽  
Experimental Investigations ◽  
Theoretical Treatment ◽  
Impact Noise ◽  
Design Changes ◽  
Machine Cycle ◽  
Mechanism Of Impact ◽  
The Impact

A case study is made on the tack driving assembly of a boot and shoe lasting machine, and relates to the impact noise occurring during part of the machine cycle. Much of the noise is radiated due to vibrations at several frequencies of the tack driver lifting lever, which is excited by the direct application of impacts during the tack driving process. An experimental approach in applying noise reduction principles to various components of the assembly has been preferred to a more complex theoretical treatment, since the identification of the mechanism of impact noise generation and its subsequent abatement is directly relevant to most machine designers faced with the possibility of impact noise problems in other types of machinery. Small design changes, based on the knowledge gained from the experimental investigations, have resulted in noise reductions from 10 to 14 dB being achieved.

Clarifying the Carbon Nanotube Actuation Mechanism: An Experimental Approach

2012 ◽  
Author(s):  
Sebastian M. Geier ◽  
Stephan Müller ◽  
Thorsten Mahrholz ◽  
Peter Wierach ◽  
Johannes Riemenschneider ◽  
...  
Keyword(s):  
Experimental Approach ◽  
Tensile Tests ◽  
Experimental Investigations ◽  
Actuation Mechanism ◽  
Different Types ◽  
Out Of Plane ◽  
Vertically Aligned ◽  
Free Strain ◽  
Single Walled Cnts ◽  
Walled Cnts

Experimental investigations of different architectures made of pure, as produced carbon nanotubes (CNTs) are the main focus of this presented article. Different types of experimental setups are used to analyze the free strain of the CNT-based architectures. According to their build-up different experimental setups like actuated tensile tests, in-plane and out-of-plane strain measurements are realized to investigate the actuation mechanism and possible dependencies. The first analyzed architecture can be characterized as a 2D paper of randomly oriented, entangled single walled CNTs, also called Bucky-paper. In contrast the second investigated architecture consists of highly oriented, vertically aligned multi walled CNTs grown on a substrate of glassy carbon. The results are evaluated according to findings of various other material quality tests in order to find a significant statement for their possible actuation mechanisms.

scholarly journals Investigating the Effect of Stepped Scarf Repair Ratio in Repaired CFRP Laminates under Compressive Loading

2020 ◽  
Vol 4 (4) ◽  
pp. 153
Author(s):  
Spyridon Psarras ◽  
Theodoros Loutas ◽  
Magdalini Papanaoum ◽  
Orestis Konstantinos Triantopoulos ◽  
Vasilis Kostopoulos
Keyword(s):  
Numerical Models ◽  
Compressive Loading ◽  
Composite Plates ◽  
Step Length ◽  
Critical Threshold ◽  
Cfrp Laminates ◽  
Threshold Size ◽  
Repair Patch ◽  
Parametric Studies ◽  
Strength And Stiffness

In this work the effectiveness of stepped repairs to damaged fiber reinforced composite materials is investigated by using previously validated numerical models which were compared with tested repaired composite plates. Parametric studies were carried out in order to assess the scarf ratio (i.e., step length to ply thickness ratio) influence on ultimate forces, displacements, stresses and stiffnesses. FE models with repair scarf ratios varying from the value of 20 to the value 60 with a step increase of 10 were developed. The numerical models allowed a direct comparison of the influence that the scarf ratio had to the strength and stiffness restoration of the repaired composite structure. The study verifies that the restoration of the strength of a damaged laminate depends largely on the size of the repair patch. Generally, the bigger the size of a patch, the stronger the repaired structure is, up to a critical threshold size. To maximize the strength restoration, it is advised that the number of steps in each patch are no less than the number of plies on the base laminate.

DELAMINATION MONITORING OF QUASI-ISOTROPIC CFRP LAMINATE USING ELECTRIC POTENTIAL CHANGE METHOD

2008 ◽  
Vol 22 (11) ◽  
pp. 869-874 ◽  
Author(s):  
MASAHITO UEDA ◽  
AKIRA TODOROKI
Keyword(s):  
Carbon Fiber ◽  
Electric Potential ◽  
Structural Reliability ◽  
Coefficient Of Thermal Expansion ◽  
Local Strain ◽  
Potential Change ◽  
Cfrp Laminate ◽  
Cfrp Laminates ◽  
Element Simulation ◽  
Fiber Reinforce Plastic

Real-time detection of delamination in carbon fiber reinforce plastic (CFRP) laminates has been requiring to maintain the structural reliability of aircraft. In this paper, electric potential change method (EPCM) was applied to monitor delaminations in quasi-isotropic CFRP laminate. As the coefficient of thermal expansion and mold shrinkage factor of carbon fiber and epoxy matrix is different, residual stress is developed in the laminate during the fabrication process of curing. The local strain variation due to delaminations was measured by EPCM utilizing the piezoresistivity of the laminate itself. Finite element simulation was performed to investigate the applicability of the method.

scholarly journals Solving self-absorption in fluorescence

IUCrJ ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 586-602 ◽  
Author(s):  
Ryan M. Trevorah ◽  
Christopher T. Chantler ◽  
Martin J. Schalken
Keyword(s):  
Software Package ◽  
Experimental Approach ◽  
Experimental Investigations ◽  
Accuracy Analysis ◽  
X Ray ◽  
Fluorescence Photon ◽  
Wide Range ◽  
Self Consistent ◽  
Consistent Method ◽  
X Ray Absorption

One of the most common types of experiment in X-ray absorption spectroscopy (XAS) measures the secondary inelastically scattered fluorescence photon. This widespread approach has a dominant systematic of self-absorption of the fluorescence photon. The large impact of self-absorption compromises accuracy, analysis and insight. Presented here is a detailed self-consistent method to correct for self-absorption and attenuation in fluorescence X-ray measurements. This method and the resulting software package can be applied to any fluorescence data, for XAS or any other experimental approach detecting fluorescence or inelastically scattered radiation, leading to a general solution applicable to a wide range of experimental investigations. The high intrinsic accuracy of the processed data allows these features to be well modelled and yields deeper potential insight.

scholarly journals Examining Cfrp Laminate Layup with Contact-Mode Ultrasonic Measurements

1993 ◽  
Vol 2 (2) ◽  
pp. 096369359300200 ◽  
Author(s):  
D K Hsu ◽  
F J Margetan
Keyword(s):  
Angular Dependence ◽  
Shear Waves ◽  
Ultrasonic Signal ◽  
Thickness Direction ◽  
Contact Mode ◽  
Cfrp Laminate ◽  
Cfrp Laminates ◽  
Ultrasonic Measurements

This letter describes contact-mode ultrasonic measurements for evaluating the layup configuration of cross-plied CFRP laminates, particularly the [0m/90n] l layup. Polarization and velocity of shear waves propagating in the thickness direction were used in deducing the percentages of 0 and 90 degree plies. The angular dependence of an acousto-ultrasonic signal was used in the determination of in-plane fiber directions.

scholarly journals Development of a Prestressing CFRP Laminate Anchorage System and Bridge Strengthening Application

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Fangyuan Li ◽  
Wenhao Li ◽  
Shaohui Lu ◽  
Yin Shen
Keyword(s):  
Carrying Capacity ◽  
Large Scale ◽  
Scale Model ◽  
Load Carrying Capacity ◽  
Cfrp Laminate ◽  
Cfrp Laminates ◽  
Anchorage System ◽  
Bridge Strengthening ◽  
Load Carrying ◽  
Working Together

For prestressed carbon fiber reinforced polymer (CFRP) tendon anchorage systems to become well established and used on a large scale, practical requirements for structure strengthening may be met by performing a relatively easy anchorage technique using prestressing CFRP laminates. From testing performed on a clip-type CFRP laminate anchorage system developed in our research group, it was revealed that this system could achieve the anchorage efficiency and the relaxation met the requirement of specification. Furthermore, the relevant indices of the anchorage system met the prestressed system standards. A test on the load-carrying capacity of a full-scale model beam demonstrated that the load-carrying capacity of the beam increased by more than 60% after it was strengthened with the anchorage system. The prestressing CFRP laminates and the bridge structure deformed and bore stress as a composite and exhibited excellent operating performance when working together.

Experimental investigations of electromagnetic punching process in CFRP laminate

2020 ◽  
pp. 1-12
Author(s):  
Liming Duan ◽  
Hao Jiang ◽  
Xu Zhang ◽  
Guangyao Li ◽  
Junjia Cui
Keyword(s):  
Experimental Investigations ◽  
Cfrp Laminate ◽  
Punching Process

scholarly journals Damage Investigation of Carbon-Fiber-Reinforced Plastic Laminates with Fasteners Subjected to Lightning Current Components C and D

2020 ◽  
Vol 10 (6) ◽  
pp. 2147
Author(s):  
Jian Chen ◽  
Xiaolei Bi ◽  
Juan Liu ◽  
Zhengcai Fu
Keyword(s):  
Carbon Fiber ◽  
Current Amplitude ◽  
Carbon Fiber Reinforced Plastic ◽  
Conduction Current ◽  
Cfrp Laminate ◽  
Cfrp Laminates ◽  
Fiber Reinforced Plastic ◽  
Lightning Current ◽  
Reinforced Plastic ◽  
Component C

The damage induced by lightning strikes in carbon-fiber-reinforced plastic (CFRP) laminates with fasteners is a complex multiphysics coupling process. To clarify the effects of different lightning current components on the induced damage, components C and D were used in simulated lightning strike tests. Ultrasonic C-scans and stereomicroscopy were used to evaluate the damage in the tested specimens. In addition, the electrothermal coupling theory was adopted to model the different effects of the arc and the current flowing through the laminate (hereinafter referred to as the conduction current) on CFRP laminates with fasteners under different lightning current components. Component C, which has a low current amplitude and a long duration, ablated and gasified the fastener and caused less damage to the CFRP laminate. Under component C, the heat produced by the arc played a leading role in damage generation. Component D, which has a high current amplitude and a short duration, caused serious surface and internal damage in the CFRP laminate and little damage to the fastener. Under component D, the damage was mainly caused by the Joule heat generated by the conduction current.

Sign in / Sign up

Export Citation Format

Share Document