Architecture Inspiration from the Microstructure and Bending Behavior of Nacre of Molluscan Shell

2011 ◽  
Vol 243-249 ◽  
pp. 6494-6498
Author(s):  
Yuan Lin An ◽  
Zhi Ming Liu ◽  
Gan Wang ◽  
Wen Jian Wu
Keyword(s):  
Mechanical Properties ◽  
Building Materials ◽  
Bending Strength ◽  
Toughening Mechanism ◽  
Three Point Bending ◽  
Fracture Surfaces ◽  
Molluscan Shell ◽  
Brick And Mortar ◽  
Bending Behavior

Nacre of molluscan shells is famous for its “brick and mortar” microstructure and possesses excellent mechanical properties. Three-point bending strengths of nacre parallel and vertical to the surfaces of platelets are tested and the different fracture surfaces were characterized. The result shows that the values of three-point bending strength in the two directions are approximately the same. Base on the microstructure of and toughening mechanism of nacre, the inspiration for architecture was put forward as follows: to redesign the building materials, toughen the architecture in several ways, and enhance the properties of architecture in all directions. The aim of the paper is to call out learning from nacre to create novel architecture and building materials.

Mechanical Properties of Carbon Nanofiber Reinforced Polylactic Acid

2007 ◽  
Vol 345-346 ◽  
pp. 1225-1228 ◽  
Author(s):  
Yoshinobu Shimamura ◽  
Atushi Yamamoku ◽  
Keiichiro Tohgo ◽  
Shigeru Tasaka ◽  
Hiroyasu Araki
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Bending Strength ◽  
Carbon Nanofiber ◽  
Weight Fraction ◽  
Three Point Bending ◽  
Fracture Surfaces ◽  
Pull Out ◽  
Twin Screw ◽  
Carbon Nanofiller

Carbon nanofiller reinforced PLA was fabricated, and the mechanical properties and heat resistivity were measured. Vapor grown carbon fiber (VGCF) produced by Showa Denko K.K. was used for reinforcement, which has 150 nm in diameter and 10 μm in length. No surface treatment of VGCF was conducted. VGCF and PLA were compounded by using a twin screw extrusion machine and then pelletized. The weight fraction of VGCF ranged from 1wt% to 10wt%. Three point bending specimens were fabricated by using injection molding. At first, three point bending tests were carried out at room temperature. The bending stiffness increased from 3GPa to as high as 5GPa, but the bending strength slightly decreased. SEM observation of the fracture surfaces indicated pull-out of VGCFs over the fracture surfaces. These results imply that adhesion between VGCF and matrix was imperfect. Then, the heat deflection temperatures and glass transition temperatures of the specimens were measured. The addition of VGCF did not increase the glass transition temperature but slightly increased the heat deflection temperature.

scholarly journals Influence of the Infill Orientation on the Properties of Zirconia Parts Produced by Fused Filament Fabrication

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3158 ◽  
Author(s):  
Santiago Cano ◽  
Tanja Lube ◽  
Philipp Huber ◽  
Alberto Gallego ◽  
Juan Alfonso Naranjo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Complex Geometries ◽  
Fused Filament Fabrication ◽  
Moisture Evaporation ◽  
Bending Tests ◽  
Three Point Bending ◽  
Different Types ◽  
Fill Pattern ◽  
The Many

The fused filament fabrication (FFF) of ceramics enables the additive manufacturing of components with complex geometries for many applications like tooling or prototyping. Nevertheless, due to the many factors involved in the process, it is difficult to separate the effect of the different parameters on the final properties of the FFF parts, which hinders the expansion of the technology. In this paper, the effect of the fill pattern used during FFF on the defects and the mechanical properties of zirconia components is evaluated. The zirconia-filled filaments were produced from scratch, characterized by different methods and used in the FFF of bending bars with infill orientations of 0°, ±45° and 90° with respect to the longest dimension of the specimens. Three-point bending tests were conducted on the specimens with the side in contact with the build platform under tensile loads. Next, the defects were identified with cuts in different sections. During the shaping by FFF, pores appeared inside the extruded roads due to binder degradation and or moisture evaporation. The changes in the fill pattern resulted in different types of porosity and defects in the first layer, with the latter leading to earlier fracture of the components. Due to these variations, the specimens with the 0° infill orientation had the lowest porosity and the highest bending strength, followed by the specimens with ±45° infill orientation and finally by those with 90° infill orientation.

Fabrication of TiAl Intermetallic by Spark Plasma Sintering

2007 ◽  
Vol 336-338 ◽  
pp. 1050-1052 ◽  
Author(s):  
Hai Tao Wu ◽  
Yun Long Yue ◽  
Wei Bing Wu ◽  
Hai Yan Yin
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Three Point Bending ◽  
The Poor ◽  
High Relative Density ◽  
Plasma Sintering ◽  
Spark Plasma

The γ-TiAl intermetallic compounds were produced at the temperature ranging from 850°C to 1050°C by the Spark Plasma Sintering (SPS) process. The effects of sintering temperature and holding time on the mechanical properties of γ-TiAl intermetallic compounds were investigated. The γ-TiAl intermetallic compounds sintered at 1050°C for 10 min showed a high relative density more than 98%, and had the best three-point bending strength of 643MPa, fracture toughness of 12 MPa·m1/2 and microhardness of 560MPa. The microstructural observations indicated typical characteristics of intergranular fracture, which meant the poor ductility of γ-TiAl intermetallic compounds.

Mechanical Characterizations of Saxidomus purpuratus Shells

2010 ◽  
Vol 434-435 ◽  
pp. 601-604 ◽  
Author(s):  
W. Yang ◽  
Y. Jiang ◽  
G.P. Zhang ◽  
Y.S. Chao ◽  
Xiao Wu Li
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Bending Strength ◽  
Target Material ◽  
Organic Matrix ◽  
Fatigue Tests ◽  
Bending Fatigue ◽  
Three Point Bending ◽  
Saxidomus Purpuratus ◽  
Scanning Electron

A sort of biological shells (Saxidomus purpuratus), which belongs to Bivalve, was selected as the target material, and hardness and dynamic three point bending fatigue tests were conducted to examine its mechanical properties. Microhardness measurements showed that the inner layer is the hardest. The indentation on the specimen with a lower bending strength was damaged more seriously by the same load. Three point bending fatigue tests demonstrated that this kind of the shells with a special structure comprising mineral and organic matrix can experience the repeated loads instead of immediate breaking. The fatigue results on a single shell investigated here indicated that the fatigue strength is usually less than the static bending strength. Most of the fatigue lives of the specimens are less than 2105 cycles. In addition, fatigue fracture surfaces are observed by scanning electron microscopy.

Study of the mechanical properties and toughening mechanism of ZrO2 particles toughened Si3N4 ceramics

2020 ◽  
Vol 10 (6) ◽  
pp. 928-933
Author(s):  
Liang Tian ◽  
Qinglin Hou ◽  
Yingxia Wang ◽  
Yihui Hou
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Hardness ◽  
Fracture Morphology ◽  
Xrd Analysis ◽  
High Thermal Stability ◽  
Toughening Mechanism ◽  
Temperature Resistance ◽  
Si3n4 Ceramics

Si3N4 ceramic has excellent properties such as high temperature resistance, high hardness, and high thermal stability, but it has the disadvantages of high hardness and brittleness and difficulty in later processing. In this paper, ZrO2 was used as toughening phase, and ZrO2 toughened Si3N4 ceramics was prepared by injection molding. The effects of ZrO2 sintering temperature and content on the mechanical properties and fracture morphology were studied. Experiments show that when the ZrO2 content is 10 wt.% and the sintering temperature reaches 1650 °C, the bending strength and fracture toughness of Si3N4 ceramics reach the maximum at the same time, which are 767 MPa and 8.7 MPa·m1/2, respectively. The density is high. XRD analysis revealed that if the sintering temperature is too high, the ZrO2/Si3N4 system will generate a large number of ZrN impurity phases that cannot be phase-transformed, which ultimately affects the ceramic properties. According to fracture morphology, the toughening mechanism of ZrO2 is stress-induced phase transition.

An investigation on the effect of nanoparticle reinforcement and weld surface shape on bending behavior of rotary friction-welded high-density polyethylene

2021 ◽  
pp. 146442072110441
Author(s):  
Vahid Asghari ◽  
Abdolvahed Kami ◽  
Abbasali Bagheri
Keyword(s):  
High Density Polyethylene ◽  
Joint Strength ◽  
Bending Strength ◽  
Welded Joint ◽  
High Density ◽  
Surface Shape ◽  
Bending Tests ◽  
Three Point Bending ◽  
Rotary Friction Welding ◽  
Bending Behavior

In this research, high-density polyethylene rods were joined together using rotary friction-welding. The effects of nanoparticle reinforcement and weld surface shape on the welded joint strength were investigated. To this aim, high-density polyethylene rods with a length of 50 mm and a diameter of 22 mm were machined, and three weld surface shapes, that is, flat, step, and conic shapes (on male and female counterparts), were created. The high-density polyethylene rods were rotary friction-welded with the addition of ZnO and SiO2 nanoparticles. The bending strength of rotary friction-welded rods was assessed by conduction of three-point bending tests. The results showed that both the weld surface shape and nanoparticles influence the bending strength of the welded joints. It was found that the step sample welds have higher bending strength (average bending depth and force of 6.27 mm and 2027.8 N, respectively). Furthermore, except for the case of flat samples, the addition of the reinforcement nanoparticles resulted in the improvement of the bending strength of the rotary friction-welded rods.

scholarly journals Influence of water to solid ratio on mechanical properties of GBFS-based geopolymer foam concrete

2018 ◽  
Vol 163 ◽  
pp. 06003
Author(s):  
Tomasz Piotrowski ◽  
Piotr Prochoń
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Sodium Silicate ◽  
Building Materials ◽  
Bending Strength ◽  
Sodium Silicate Solution ◽  
Volume Density ◽  
Foam Concrete ◽  
Solid Ratio ◽  
Solid Part

The development of sustainable building materials with reduced environmental footprint in both, manufacturing and operational phases of the material lifecycle, is attracting increased interest in the construction industry worldwide. A recent innovation, the geopolymer foam concrete, combines the performance benefits and operational energy savings achievable through the use of lightweight foam concrete, with the cradle-togate emissions reductions obtained through the use of a geopolymer binder derived from granulated blast-furnace slag (GBFS). In this study mechanical properties of GBFS-based foam concrete were investigated for samples of different water to solid ratio (0.252, 0.287 and 0.321). According to ASTM C 796-97 both mass of the foaming solution and water in sodium silicate solution was considered as part of the total amount of mixing water. As a solid part, GBFS and solid part of activators (NaOH and sodium silicate) was accounted. A group of specimens (40x40x160 beams and 100x100x100 cubes) have been prepared and volume density, bending, compressive strength tests have been performed. In a result an optimized lightweight GBFS-based geopolymer foam concrete was obtained, characterized by 1.8 kg/dm3 volume density, 2.6 MPa bending strength and 51.8 MPa compressive strength measured on beams and 44.1 MPa compressive strength on cubes.

Effect of Zr Content on Properties of Mg-Zr PM Damping Alloys

2011 ◽  
Vol 84-85 ◽  
pp. 58-63
Author(s):  
Zi Li Liu ◽  
Fei Fei ◽  
Ping Shen ◽  
Gui Bin Zhou ◽  
Xi Qin Liu
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Bending Test ◽  
Damping Capacity ◽  
Micro Hardness ◽  
Three Point Bending ◽  
Zr Addition ◽  
Maximum Value ◽  
Damping Peak ◽  
Zr Alloy

Mg-xZr damping alloys (x=0.6, 1.5, 2.5, 5, mass %) were prepared by PM (powder metallurgy ) technology, and effects of Zr contents on microstructure, mechanical properties and damping capacities of Mg-xZr damping alloys were researched by three-point bending test and DMA, etc. The results show that the microstructure become into strip-shaped morphology, more granular particles appear in the grain boundaries or inside grains, and the grains are more refined with the increase of Zr additions. Micro-hardness and bending strength of the Mg-xZr damping alloys increase with increasing addition of Zr, and reach the maximum value with Zr addition of 2.5%. The damping capacities of Mg-xZr alloys increase slowly with the temperature from 27°C to 100°C, and increase rapidly above 100°C. The damping peaks appear at temperature of 160°C. Mg-5％Zr alloy exhibits the highest damping capacity, and its tanf value reaches to 0.084. The temperature of the damping peak increases with increasing frequencies, showing the characteristic of relaxation damping.

Effects of Electric Fields on the Bending Behavior of Piezoelectric Composite Laminates

1999 ◽  
Vol 604 ◽  
Author(s):  
J.Q Cheng ◽  
T.Y. Zhang ◽  
M.H. Zhao ◽  
C.F. Qian ◽  
S. W. R. Lee ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Composite Laminates ◽  
Bending Strength ◽  
Piezoelectric Composite ◽  
Element Analysis ◽  
Three Point Bending ◽  
Electrical Loading ◽  
Bending Behavior

AbstractThis Paper investigates the bending behavior of piezoelectric laminates under combined mechanical and electrical loading. The laminate has a PZT - 5H ceramic core sandwiched by graphite/epoxy plates. Three-point bending tests and in-situ acoustic emission measurements were conducted on the PZT-5H laminates preloaded by an applied electric field. The results show that the PZT-5H core fractures first and then delaminaton occurs along the tensile stressed interface between the PZT ceremic and the graphite/epoxy layer. Finite element analysis was performed to analyze stresses in the sandwich structure under combined mechanical and electrical loading. Consequently, the bending strength of the PZT core was evaluated from the experiment data. The electric field, either positive or negative, reduces the fracture strength of the pzt core.

Fabrication of Ti2AlC/TiAl Composites with the Addition of Niobium by Spark Plasma Sintering

2008 ◽  
Vol 368-372 ◽  
pp. 1004-1006 ◽  
Author(s):  
Yun Long Yue ◽  
H.T. Wu
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Three Point Bending ◽  
Plasma Sintering ◽  
Titanium Aluminum ◽  
Spark Plasma ◽  
The Difference ◽  
The Relationship

Ti2AlC/TiAl composites with the addition of niobium were prepared by spark plasma sintering using titanium, aluminum, niobium elemental powers and TiC particles as reactants. The experimental and analytical studies on this kind of material concentrated on the relationship between reinforcement phase and mechanical properties. The Ti2AlC/TiAl composites with 5% niobium exhibit high mechanical properties. The three-point bending strength and fracture toughness reaches as high as 915MPa and 23 MPa·m1/2, respectively. It is found that the in-situ reaction occurs at 1100°C with the addition of niobium at the interface between the TiAl matrix and original reinforcement TiC. Further XRD results indicate that the difference in the reinforcement phase from TiC to Ti2AlC is one of the most important origins to the variation in mechanical properties.

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