scholarly journals Fiber orientation effect on fracture toughness of silk fiber-reinforced zeolite/HDPE composites

2021 ◽  
Vol 49 (1) ◽  
pp. 128-134
Author(s):  
P Purnomo ◽  
Putu Setyarini ◽  
Agus Anggono

The aim of this work is to investigate the fracture toughness and deformation of silk fiber (SF)-reinforced zeolite (Z)/high density polyathylene (HDPE) composites. The chopped SFs are arranged in the thickness middle of the dry mixture of Z/HDPE powder that has been prepared in a mold. Composites were produced by the compression molding to produce double-edge notch tensile (DENT). The fracture toughness characterization was carried out based on essential work of fracture method. The results show that the presence of SF increased the essential fracture work even though the non-essential fracture work for Z/HDPE was higher than S-Z/HDPE. The evolution of plastic zone growth coincides with the growth of the fracture process zone (FPZ) whose height has no effect on energy consumption.

Author(s):  
David A. Dillard ◽  
Yeh-Hung Lai ◽  
Michael Budinski ◽  
Craig Gittleman

Through the thickness flaws or “pinholes” in proton exchange membranes (PEM) allow gas crossover that can lead to fuel cell failure. The formation of these flaws is not fully understood, but one possible mechanism is that small flaws could grow through crack propagation in the fracture mechanics sense. Although relatively brittle features are sometimes observed in failures resulting under simulated fuel cell conditions, the stress strain plots of the membranes themselves exhibit considerable ductility. In an effort to use fracture mechanics principles to characterize PEMs, fracture parameters associated with the essential work of fracture from double edge notch tensile (DENT) specimens; the tear energy obtained from the trouser tear test; and cutting energies associate with knife slitting were measured and compared. Presumably through reducing crack tip blunting, the knife slitting test is able to measure fracture energies as low as 200J/m2, two orders of magnitude smaller than measured in the other tests. The results are sensitive to rate, temperature, and moisture level. Although the implications of these properties to fuel cell durability are not yet understood, they may have applicability in the more brittle features that are sometimes observed.


2019 ◽  
Vol 961 ◽  
pp. 16-22
Author(s):  
Purnomo ◽  
Putu Hadi Setyarini ◽  
Dwi Sulistyaningsih

The aim of this study is to investigate the behavior of banana fiber (BF)-low-density polyethylene (LDPE) composite fracture toughness. The LDPE pellets are transformed into powder form which is then functioned as a matrix reinforced with banana fiber (BF). The composites were formed by injection molding techniques which are followed by atmospheric-pressure annealing at 90°C for 24 hours. The composite fracture toughness behavior was evaluated using the essential work of fracture (EWF) approach. The results show that fracture toughness which is characterized by essential fracture work (we) value increases by the presence of BF up to 5 wt.%. However, the we value starts to decrease in the composite with BF content of 6 wt.%. There is a mismatch about the phenomenon of non-essential fracture work. Stress-whitened zones can be seen and observed but non-essential fracture work based on curves is a negative value.


2000 ◽  
Vol 40 (12) ◽  
pp. 2558-2568 ◽  
Author(s):  
Emma C. Y. Ching ◽  
Wendy K. Y. Poon ◽  
Robert K. Y. Li ◽  
Yiu-Wing Mai

2011 ◽  
Vol 275 ◽  
pp. 229-233 ◽  
Author(s):  
Cheng Zhu Liao ◽  
Sie Chin Tjong

Polyamide 6 (PA6) based nanocomposites toughened with 20 wt% maleated styrene-ethylene-butylene-stryrene (mSEBS) reinforced with 1-7 wt% silicon carbide nanoparticles (SiCp) were fabricated via melt blending followed by injection molding. Tensile results showed that SiCp additions improve the Young’s modulus and tensile strength of PA6/mSEBS blends but decrease their tensile ductility and impact strength. EWF test revealed that the SiCp additions reduce both the specific essential work of fracture and specific non-essential plastic work of fracture. Thus SiCp additions are detrimental to the fracture toughness of PA6/mSEBS blend.


2020 ◽  
Vol 20 (1) ◽  
pp. 315-322
Author(s):  
Tarek Houari ◽  
Mohamed Benguediab ◽  
Azzeddine Belaziz ◽  
Mohamed Belhamiani ◽  
Abdelkrim Aid

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