Elasticity Solutions for Fiber-Reinforced, Polymeric Composite Laminates.

1974 ◽  
Author(s):  
Richard D. Schile
2012 ◽  
Vol 24 (8) ◽  
pp. 991-1006 ◽  
Author(s):  
Oliver J Myers ◽  
George Currie ◽  
Jonathan Rudd ◽  
Dustin Spayde ◽  
Nydeia Wright Bolden

Defects in composite laminates are difficult to detect because of the conductive and paramagnetic properties of composite materials. Timely detection of defects in composite laminates can improve reliability. This research illustrates the preliminary analysis and detection of delaminations in carbon fiber laminate beams using a single layer of magnetostrictive particles and noncontacting concentric magnetic excitation and sensing coils. The baseline analytical models also begin to address the intrusive nature of the magnetostrictive particles as well as relate the applied excitation field with the stress and magnetic flux densities induced in the magnetostrictive layer. Numerical methods are used to begin to characterize the presence of magnetostrictive particles in the laminate and the behavior of the magnetostrictive particles in relationship to the magnetic field used during sensing. Unidirectional laminates with embedded delaminations are used for simulations and experimentations. A novel, yet simplified fabrication method is discussed to ensure consistent scanning and sensing capabilities. The nondestructive evaluation scanning experiments were conducted with various shapes and sizes of damages introduced into carbon fiber–reinforced polymeric composite structures. The results demonstrate high potential for magnetostrictive particles as a low-cost, noncontacting, and reliable sensor for nondestructive evaluation of composite materials.


2005 ◽  
Vol 297-300 ◽  
pp. 2897-2902 ◽  
Author(s):  
Jin Woo Kim ◽  
Jung Ju Lee ◽  
Dong Gi Lee

The study for strength calculation of one way fiber-reinforced composites and the study measuring precisely fiber orientation distribution were presented. However, because the DB that can predict mechanical properties of composite material and fiber orientation distribution by the fiber content ratio was not constructed, we need the systematic study for that. Therefore, in this study, we investigated what effect the fiber content ratio and fiber orientation distribution have on the strength of composite sheet after making fiber reinforced polymeric composite sheet by changing fiber orientation distribution with the fiber content ratio. The result of this study will become a guide to design data of the most suitable parts design or fiber reinforced polymeric composite sheet that uses the fiber reinforced polymeric composite sheet in industry spot, because it was conducted in terms of developing products. We studied the effect the fiber orientation distribution has on tensile strength of fiber reinforced polymeric composite material and achieved this results below. We can say that the increasing range of the value of fiber reinforced polymeric composite’s tensile strength in the direction of fiber orientation is getting wider as the fiber content ratio increases. It shows that the value of fiber reinforced polymeric composite’s tensile strength in the direction of fiber orientation 90° is similar with the value of polypropylene’s intensity when fiber orientation function is J= 0.7, regardless of the fiber content ratio. Tensile strength of fiber reinforced polymeric composite is affected by the fiber orientation distribution more than by the fiber content ratio.


2021 ◽  
Vol 36 (2) ◽  
pp. 213-218
Author(s):  
M. D. D. Boudiaf ◽  
L. Hemmouche ◽  
M. A. Louar ◽  
A. May ◽  
N. Mesrati

Abstract In this study, the strain rate sensitivity of a discontinuous short fiber reinforced composite and the strain rate effect on the damage evolution are investigated. The studied material is a polymeric composite with a polyamide 6.6 matrix reinforced with oriented randomly short glass fibers at a 50% weigh ratio (PA6.6GF50). Tensile tests at low and high strain rate are conducted. In addition, interrupted tensile tests are carried out to quantify the damage at specific stress levels and strain rates. To perform the interrupted tensile tests, an intermediate fixture is realized via double notched mechanical fuses with different widths designed to break at suitable stress levels. The damage is estimated by the fraction of debonded fibers and matrix fractures. Based on the experimental observations, it is concluded that the ultimate stress and strain, and the damage threshold are mainly governed by the strain rate. Furthermore, it is established that the considered composite has a non-linear dynamic behavior with a viscous damage nature.


Author(s):  
Joao F. Silva ◽  
Joao P. Nunes ◽  
Joao C. Velosa

Polymer composites are an excellent alternative to replace more traditional materials in the fabrication of pressure cylinders for common applications. They minimize the weight and improve the mechanical, impact and corrosion behavior, which are relevant characteristics for almost all current and future large scale pressure cylinder applications, such as liquid filters and accumulators, hydrogen cell storage vessels, oxygen bottles, etc. A new generation of composite pressure vessels has been studied in this work. The vessels consist on a thermoplastic liner wrapped with a filament winding glass fiber reinforced polymer matrix structure. A conventional 6-axis CNC controlled filament winding equipment was used to manufacture the thermosetting matrix composite vessels and adapted for production of thermoplastic matrix based composite vessels. The Abaqus 6.4.2 FEM package was used to predict the mechanical behavior of pressure vessels with capacity of approximately of 0.068 m3 (68 liters) for a 0.6 MPa (6 bar) pressure service condition according to the requirements of the EN 13923 standard, namely, the minimum internal burst pressure. The Tsai-Wu and von-Mises criteria were used to predict composite laminate and thermoplastic liner failures, respectively, considering the elasto-plastic behavior of the HDPE liner and the lamina properties deducted from the micromechanical models for composite laminates. Finally, the results obtained from the simulations were compared with those obtained from the experimental pressure tests made on the thermoplastic liners and final composite vessels.


2014 ◽  
Vol 564 ◽  
pp. 501-506 ◽  
Author(s):  
Mohd Azuwan Maoinser ◽  
Faiz Ahmad ◽  
Safian Shariff ◽  
Tze Keong Woo

Drill point angle of twist drill has a significant effect on thrust force and delamination factor on drilled holes in fiber reinforced polymer (FRP) composites. In this study, three drill point angle of twist drill; 85°, 118° and 135° were used to drill holes in hybrid fiber reinforced polymeric composite (HFRP). HFRP composites were fabricated using vacuum infusion molding (VIM) technique. The test samples were cured at 90°C for two hours. In drilling process various drill point angle and feed rate were employed to investigate the effect of both parameters on thrust force and delamination factor when drilling the HFRP composite. The results showed that small drill point angle and low feed rate can reduce the thrust force leading to the reduction of damage factor at the holes entrance and exit.


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