Model and Maximal Pull-Out Force of Helicoidal Fiber Structure in the Underpinnings of Tumblebug Cuticle

2011 ◽  
Vol 686 ◽  
pp. 427-431 ◽  
Author(s):  
Bin Chen ◽  
Da Gang Yin ◽  
Quan Yuan ◽  
Ji Luo ◽  
Jing Hong Fan
Keyword(s):  
Fracture Toughness ◽  
Composite Structures ◽  
High Performance ◽  
Parallel Fiber ◽  
Fiber Structure ◽  
Protein Matrix ◽  
The Core ◽  
Pull Out ◽  
Collagen Protein ◽  
Scanning Electron

The observation of scanning electron microscope (SEM) on the cuticle of Tumblebug shows that the cuticle is a kind of biocomposite consisting of chitin-fibers and collagen protein matrix. The observation also shows that there are many underpinnings in the cuticle. The underpinnings are also a kind of biological composite consisting of chitin-fiber layers and collagen protein matrixes. More careful observation indicates that the chitin-fiber layers enwrap the core of the underpinnings forming a kind of helicoidal fiber structure. The maximal pull-out force of the helicoidal fiber structure, related to the fracture toughness of the underpinnings, is theoretically and experimentally investigated and compared with that of parallel fiber structure. It shows that the maximal pull-out force of the helicoidal fiber structure is larger than that of the parallel fiber structure, which gives profitable information for the design of man-made high-performance composites and composite structures.

Helicoidal-Rounded-Hole Microstructure of Mature Shankbone

2011 ◽  
Vol 460-461 ◽  
pp. 652-655
Author(s):  
Bin Chen ◽  
Ji Luo ◽  
Quan Yuan
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Protein Matrix ◽  
Pullout Force ◽  
Sem Observation ◽  
Collagen Protein ◽  
Scanning Electron

Scanning electron microscope (SEM) observation on a mature shankbone shows that the bone is a kind of bioceramic composite consisting of hydroxyapatite sheets and collagen protein matrix. The observation also shows that there are many holes in the bone and that the hydroxyapatite sheets near by these holes helicoidally round these holes forming a kind of helicoidally-rounded-hole microstructure (HRHM). The maximum pullout force of the HRHM is investigated and compared with that of non-helicoidally-rounded-hole microstructure (NHRHM). It shows that the HRHM could markedly increase the maximum pullout force of the hydroxyapatite sheets compared to the NHRHM and therefore enhance the fracture toughness of the bone.

Microstructure and Toughness Mechanism of Tooth

2011 ◽  
Vol 467-469 ◽  
pp. 567-570
Author(s):  
Bin Chen ◽  
Ji Luo ◽  
Quan Yuan ◽  
Jing Hong Fan
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Protein Matrix ◽  
Collagen Protein ◽  
Fine Microstructure ◽  
Representative Model ◽  
Toughness Mechanism ◽  
Parallel Distribution ◽  
Scanning Electron

Tooth is a kind of biomaterial in nature. It behaves favorable strength, stiffness and fracture toughness, which are closely related to its fine microstructure. The observation of scanning electron microscope (SEM) on a mature tooth shows that the tooth is a kind of natural bioceramic composite consisting of hydroxyapatite layers and collagen protein matrix. The observation also shows that the hydroxyapatite layers consist of long and thin hydroxyapatite sheets and that all the hydroxyapatite sheets are arranged in a kind of parallel distribution. The maximum pullout energy of the hydroxyapatite sheets, which is closely related to the fracture toughness of the tooth, is investigated based on the representative model of the parallel distribution. It shows that the long and thin shape as well as the parallel distribution of the hydroxyapatite sheets increase the maximum pullout energy and enhance the fracture toughness of the tooth.

Intercrossed Microstructures of Hydroxyapatite Sheets of Tibia Bone

2011 ◽  
Vol 460-461 ◽  
pp. 648-651
Author(s):  
Bin Chen ◽  
Quan Yuan ◽  
Ji Luo
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Protein Matrix ◽  
Pullout Force ◽  
Tibia Bone ◽  
Collagen Protein ◽  
Scanning Electron

The observation of scanning electron microscope (SEM) showed that a tibia bone is a kind of bioceramic composite consisting of hydroxyapatite layers and collagen protein matrix. All the hydroxyapatite layers are parallel with the surface of the bone and consist of numerous hydroxyapatite sheets. The observation also showed there is a kind of intercrossed microstructure of the hydroxyapatite sheets. In which the hydroxyapatite sheets in an arbitrary hydroxyapatite layer make a large intercrossed angle with the hydroxyapatite sheets in its adjacent hydroxyapatite layers. The maximum pullout force of the intercrossed microstructure, which is closely related to the fracture toughness of the bone, was investigated and compared with that of the parallel microstructure of the sheets through their representative models. Result indicated that the maximum pullout force of the intercrossed microstructure is markedly larger than that of the parallel microstructure.

Correlation between Microstructure and Toughness of Crab Carapace

2011 ◽  
Vol 689 ◽  
pp. 395-399 ◽  
Author(s):  
Bin Chen ◽  
Da Gang Yin ◽  
Quan Yuan ◽  
Jing Hong Fan
Keyword(s):  
Fracture Toughness ◽  
High Fracture Toughness ◽  
Calcite Crystal ◽  
Protein Matrix ◽  
High Fracture ◽  
Collagen Protein ◽  
Fine Microstructure ◽  
Representative Model ◽  
Parallel Distribution ◽  
Scanning Electron

Crab carapace is a kind of biomaterial in nature. It behaves favorable strength, stiffness and fracture toughness, which are closely related to its fine microstructure. The observation of scanning electron microscope (SEM) on the carapace of a Cyclodorippoidea crab shows that the carapace is a kind of natural bioceramic composite consisting of calcite crystal layers and collagen protein matrix. The observation also shows that the calcite crystal layers consist further of long and thin calcite crystal sheets and that all the calcite crystal sheets are arranged in a kind of parallel distribution. The maximum pullout energy of the calcite crystal sheets, which is closely related to the fracture toughness of the carapace, is investigated based on the representative model of the parallel distribution. It shows that the long and thin shape as well as the parallel distribution of the calcite crystal sheets enhance the maximum pullout energy and ensure the high fracture toughness of the carapace.

Fiber-Spiral Microstructures of Bamboo and Biomimetic Research

2010 ◽  
Vol 447-448 ◽  
pp. 657-660
Author(s):  
Bin Chen ◽  
Quan Yuan ◽  
Ji Luo
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Spiral Structure ◽  
Bamboo Fiber ◽  
Parallel Fiber ◽  
Fiber Structure ◽  
Fiber Reinforced ◽  
Sem Observation ◽  
Scanning Electron

The microstructures of a whangee (a kind of bamboo) were observed with a scanning electron microscope (SEM). It showed that the whangee is a kind of natural cellular biocomposite consisting of countless bamboo cells. The bamboo cells are columnar and all of them are parallel with the surface of the bamboo. The observation also showed that the walls of the bamboo cell are a kind of fiber-reinforced biocomposite with bamboo fiber-spiral mcirstructure. Based on the SEM observation, a kind of biomimetic composite with the fiber-spiral structure was fabricated. The fracture toughness of the composite was investigated and compared with that of the conventional composite with parallel-fiber structure. It showed that the fracture toughness of the biomimetic composite is markedly larger than that of the conventional composite.

Effect of the Ratio of Co to Ni+Co on the Microstructures and Mechanical Properties of Ti(C, N)-Based Cermets

2017 ◽  
Vol 726 ◽  
pp. 292-296 ◽  
Author(s):  
Peng Wu ◽  
Shao Cun Liu ◽  
Xiu Rong Jiang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Rupture Strength ◽  
Hard Particle ◽  
Core Size ◽  
Transverse Rupture Strength ◽  
X Ray ◽  
The Core ◽  
Scanning Electron

The microstructures of the prepared Ti(C, N)-based cermets with various ratios of Co to Ni+Co were studied using X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Mechanical properties such as transverse rupture strength (TRS), fracture toughness (K1C) and hardness (HRA) were also measured. The results showed that when Ni was partly replaced by Co, the core size of hard particle and the thickness of rim phase changed. With the increasing of the ratio of Co to Ni+Co, the porosity of the cermets increased gradually, the fracture toughness of the cermets decreased gradually, the transverse rupture strength increased firstly and then decreased, the hardness changed slightly。When the ratio of Co to Ni+Co was 0.2, the cermets had better transverse rupture strength (TRS), which was characterized by fine grains and the moderate thickness of rim phase in the binder.

Indentation Fracture Toughness of Al2O3 + GPLs and Si3N4 + GPLs Systems

2016 ◽  
Vol 368 ◽  
pp. 166-169 ◽  
Author(s):  
Richard Sedlák ◽  
Alexandra Kovalčíková ◽  
Monika Tatarková ◽  
Pawel Rutkowski ◽  
Ján Dusza
Keyword(s):  
Fracture Toughness ◽  
Ceramic Composites ◽  
Crack Deflection ◽  
Crack Branching ◽  
Hot Press ◽  
Indentation Fracture ◽  
Pull Out ◽  
Crack Type ◽  
Indentation Fracture Toughness ◽  
Scanning Electron

The influence of 1 wt.% and 2 wt.% of graphene platelets (GPLs) addition on indentation fracture toughness (IF) of aluminium oxide (Al2O3) and silicon nitride (Si3N4) based composites has been investigated and compared to the monoliths. Ceramic composites reinforced with GPLs were prepared using hot-press processing technology. Microstructures were observed at fracture surfaces by scanning electron microscopy (SEM). Crack type identification was performed by gradually polishing of the indentation surface and mechanical properties of both systems were measured. Indentation fracture toughness was calculated by various methods and R-curves were prepared. The main activated toughening mechanisms, responsible for the increased fracture toughness are crack deflection, crack branching and crack bridging in the forms of graphene sheet pull-out or graphene necking.

Mode-II fracture of nanostitched para-aramid/phenolic nanoprepreg composites by end-notched flexure

2020 ◽  
Vol 54 (24) ◽  
pp. 3537-3557
Author(s):  
Kadir Bilisik ◽  
Gulhan Erdogan ◽  
Erdal Sapanci ◽  
Sila Gungor
Keyword(s):  
Fracture Toughness ◽  
Composite Structures ◽  
Phenolic Resin ◽  
Mode Ii ◽  
Stick Slip ◽  
Blunt Crack ◽  
Pristine Sample ◽  
Pull Out ◽  
Filament Bundles ◽  
Phenolic Composite

The mode-II interlaminar fracture toughness considering the end-notched flexure method of nanostitched para-aramid/phenolic composite structures was investigated. The fracture toughness (GIIC) of the nanostitched and stitched composites exhibited a slight increase as compared to the pristine sample. Hence, the nanostitching enhanced the fracture toughness of the para-aramid/phenolic composite structures. Although the type of stitch fiber was not effective, the fabric interlacement frequency, notably prepreg Twaron nanostitched yarn and basket nanoprepreg biaxial interlaced fabric was of critical importance. The principle mechanism for raising the GIIC in the nanostitched composite structure was the interlayer resin fracture particularly as a form of slight shear hackle marks. Cracks grew around the inter- and intrayarn boundaries where the resin was fractured half way around each yarn cross-section. This is called a “zigzag crack path,” and microcracks moved to the through-the-thickness of the composite where nanostitching arrested the crack growth and suppressed delamination in the stitching zone. At the blunt crack tip, carbon nanotubes in the phenolic resin and multiple filament bundles probably diminished the stress clustering via friction/debonding/pull-out/sliding or stick-slip. Thus, nanostitched para-aramid/phenolic composite structures demonstrated better damage tolerance behavior considering the neat structure.

Investigation to the Cross Microstructure of Hydroxyapatite Sheets of a Cannon Bone

2007 ◽  
Vol 361-363 ◽  
pp. 479-482
Author(s):  
Bin Chen ◽  
Xiang He Peng ◽  
Shi Tao Sun
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Protein Matrix ◽  
Pullout Force ◽  
Collagen Protein ◽  
The Cross ◽  
Scanning Electron

Bone possesses excellent mechanical properties, which are closely related to its favorable microstructures optimized by nature through many centuries. In this work, a scanning electron microscope (SEM) was used to observe the microstructures of a cannon bone. It showed that the bone is a kind of bioceramic composite consisting of hydroxyapatite layers and collagen protein matrix. The hydroxyapatite layers are composed of long and thin hydroxyapatite sheets. The hydroxyapatite sheets in different hydroxyapatite layers distribute along different orientations, which composes a kind of cross microstructure. The maximum pullout force of the cross microstructure was investigated and compared with that of the 0° microstructure with their representative models. The result indicated that the maximum pullout force of the cross microstructure is markedly larger than that of the 0° microstructure.

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