Influence of Stress Ratio on the Reliability of Al/Carbon-Fiber Composite Hydrogen Tanks

2008 ◽  
Author(s):  
Haiyan Bie ◽  
Ping Xu ◽  
Jinyang Zheng ◽  
Fangming Kai ◽  
Pengfei Liu ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Hydrogen Storage ◽  
Stress Ratio ◽  
Fiber Composite ◽  
Density Ratio ◽  
Random Variables ◽  
Theoretical Method ◽  
Carbon Fiber Composite ◽  
Composite Layers ◽  
The Relationship

Hydrogen has been proposed as an important energy source for fuel cell vehicles (FCV), and the hydrogen storage tank is considered to be indispensable key equipment for hydrogen application. Currently, Al/carbon-fiber composite hydrogen tanks have become a study focus due to their outstanding properties such as high stiffness-density and strength-density ratio. In standards of this type hydrogen tanks, stress ratio is a primary parameter to be determined. Raising the stress ratio, the reliability will be increased; however, the hydrogen storage density will be decreased accordingly. In this paper, a study on the relationship between the stress ratio and reliability is carried out based on the static strength reliability analysis. The stress-strength interference model is used for the calculation of reliability. For fiber reinforced hydrogen tanks, the stress variance is mainly influenced by two classes of random variables, and the quantity of random variables is affected by the number of composite layers which depends on the stress ratio. So by analysis of stress distribution, the influence of stress ratio on the reliability is revealed, and a theoretical method is developed that can be used for selecting rational stress ratio in the standard.

Self-Adaptable Carbon Fiber Composite

2018 ◽  
Author(s):  
Arnaldo Casalotti ◽  
Krishna C. Chinnam ◽  
Giulia Lanzara
Keyword(s):  
Carbon Fiber ◽  
Smart Materials ◽  
Structural Integrity ◽  
Fiber Composite ◽  
Carbon Fiber Composites ◽  
Smart Composite ◽  
Temperature Dependent ◽  
Carbon Fiber Composite ◽  
Composite Layers ◽  
Actual Material

This article illustrates an approach to develop innovative smart materials based on carbon fiber composites. The proposed approach relies on the use of ultra-light strain sensors that are embedded into the composite and are adopted to monitor in real-time the actual material configuration. Such sensors are composed of electrospun PVDF fibers that exploit piezoelectricity to identify strain and thanks to their extreme lightweight can easily be embedded within the composite layers without affecting the structural integrity. On the other hand, the composite is equipped with a system of internal distributed heaters that can locally and globally vary the composite temperature. Since the adopted epoxy has a considerable temperature-dependent behaviour, it is possible to control its stiffness and thus to control the structural frequencies and damping. By coupling the sensing system with the control system, the structural properties are tuned to match prescribed working conditions, thus optimizing the performance of the proposed smart system. The proposed approach is investigated experimentally by manufacturing prototypes of the smart composite and by performing multiple tests to study the material response and evaluate the obtained performance.

Prestressed Carbon Fiber Composite Overwrapped Gun Tube

2008 ◽  
Author(s):  
Andrew Littlefield ◽  
Edward Hyland ◽  
Jack Keating
Keyword(s):  
Carbon Fiber ◽  
Fiber Composite ◽  
Carbon Fiber Composite

scholarly journals Lightweight Cellulose/Carbon Fiber Composite Foam for Electromagnetic Interference (EMI) Shielding

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1319 ◽  
Author(s):  
Ran Li ◽  
Huiping Lin ◽  
Piao Lan ◽  
Jie Gao ◽  
Yan Huang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Electromagnetic Interference ◽  
Fiber Composite ◽  
Carbon Fiber Composites ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Carbon Fiber Composite ◽  
Foaming Process ◽  
Long Carbon Fibers

Lightweight electromagnetic interference shielding cellulose foam/carbon fiber composites were prepared by blending cellulose foam solution with carbon fibers and then freeze drying. Two kinds of carbon fiber (diameter of 7 μm) with different lengths were used, short carbon fibers (SCF, L/D = 100) and long carbon fibers (LCF, L/D = 300). It was observed that SCFs and LCFs built efficient network structures during the foaming process. Furthermore, the foaming process significantly increased the specific electromagnetic interference shielding effectiveness from 10 to 60 dB. In addition, cellulose/carbon fiber composite foams possessed good mechanical properties and low thermal conductivity of 0.021–0.046 W/(m·K).

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