Simulation of the Impact of Mechanical Property Variability on Railway Behaviour subject to Static Loading

2011 ◽  
Author(s):  
V. Alves Fernandes ◽  
S. Costa d'Aguiar ◽  
F. Lopez-Caballero
Keyword(s):  
Mechanical Property ◽  
Static Loading ◽  
The Impact

scholarly journals Design and Mechanical Properties Verification of Gradient Voronoi Scaffold for Bone Tissue Engineering

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 664
Author(s):  
Haiyuan Zhao ◽  
Yafeng Han ◽  
Chen Pan ◽  
Ding Yang ◽  
Haotian Wang ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Tissue Engineering ◽  
Elastic Modulus ◽  
Porous Structure ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Voronoi Tessellation ◽  
Impact Resistance ◽  
Natural Bone ◽  
The Impact

In order to obtain scaffold that can meet the therapeutic effect, researchers have carried out research on irregular porous structures. However, there are deficiencies in the design method of accurately controlling the apparent elastic modulus of the structure at present. Natural bone has a gradient porous structure. However, there are few studies on the mechanical property advantages of gradient bionic bone scaffold. In this paper, an improved method based on Voronoi-tessellation is proposed. The method can get controllable gradient scaffolds to fit the modulus of natural bone, and accurately control the apparent elastic modulus of porous structure, which is conducive to improving the stress shielding. To verify the designed structure can be fabricated by additive manufacturing, several designed models are obtained by SLM and EBM. Through finite element analysis (FEA), it is verified that the irregular porous structure based on Voronoi-tessellation is more stable than the traditional regular porous structure of the same structure volume, the same pore number and the same material. Furthermore, it is verified that the gradient irregular structure has a better stability than the non-gradient structure. An experiment is conducted successfully to verify the stability performance got by FEA. In addition, a dynamic impact FEA is also performed to simulate impact resistance. The result shows that the impact resistance of the regular porous structure, the irregular porous structure and the gradient irregular porous structure becomes better in turn. The mechanical property verification provides a theoretical basis for the structural design of gradient irregular porous bone tissue engineering scaffolds.

scholarly journals Static Loading Tests of Glued Laminated Timber Joints with Drift-Pins. The Effect of MOE on Anisotropy of Mechanical Property.

2001 ◽  
Vol 50 (7) ◽  
pp. 745-750
Author(s):  
Masaki HARADA ◽  
Tomoyuki HAYASHI ◽  
Masahiko KARUBE ◽  
Akimitsu IIDA ◽  
Kohei KOMATSU
Keyword(s):  
Mechanical Property ◽  
Static Loading ◽  
Glued Laminated Timber ◽  
Loading Tests ◽  
Timber Joints

scholarly journals Fracture Resistance of Zirconia Oral Implants In Vitro: A Systematic Review and Meta-Analysis

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 562 ◽  
Author(s):  
Annalena Bethke ◽  
Stefano Pieralli ◽  
Ralf-Joachim Kohal ◽  
Felix Burkhardt ◽  
Manja von Stein-Lausnitz ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Static Loading ◽  
Fracture Resistance ◽  
Tetragonal Zirconia ◽  
Present Review ◽  
Hydrothermal Aging ◽  
Oral Implants ◽  
Electronic Screening ◽  
The Impact ◽  
Zirconia Implants

Various protocols are available to preclinically assess the fracture resistance of zirconia oral implants. The objective of the present review was to determine the impact of different treatments (dynamic loading, hydrothermal aging) and implant features (e.g., material, design or manufacturing) on the fracture resistance of zirconia implants. An electronic screening of two databases (MEDLINE/Pubmed, Embase) was performed. Investigations including > 5 screw-shaped implants providing information to calculate the bending moment at the time point of static loading to fracture were considered. Data was extracted and meta-analyses were conducted using multilevel mixed-effects generalized linear models (GLMs). The Šidák method was used to correct for multiple testing. The initial search resulted in 1864 articles, and finally 19 investigations loading 731 zirconia implants to fracture were analyzed. In general, fracture resistance was affected by the implant design (1-piece > 2-piece, p = 0.004), material (alumina-toughened zirconia/ATZ > yttria-stabilized tetragonal zirconia polycrystal/Y-TZP, p = 0.002) and abutment preparation (untouched > modified/grinded, p < 0.001). In case of 2-piece implants, the amount of dynamic loading cycles prior to static loading (p < 0.001) or anatomical crown supply (p < 0.001) negatively affected the outcome. No impact was found for hydrothermal aging. Heterogeneous findings of the present review highlight the importance of thoroughly and individually evaluating the fracture resistance of every zirconia implant system prior to market release.

Influence of Injection Conditions on the Mechanical Property of MWCNTs/ PC Nanocomposites

2014 ◽  
Vol 983 ◽  
pp. 94-98 ◽  
Author(s):  
Li Jun Wang ◽  
Jian Hui Qiu ◽  
Eiichi Sakai
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Bending Strength ◽  
Surface Hardness ◽  
Interfacial Interaction ◽  
Multiwalled Carbon ◽  
The Matrix ◽  
The Impact ◽  
Scanning Electron

The melting mixing was applied in the preparation of Multiwalled carbon nanotubes/Polycarbonate (MWCNTs/PC) nanocomposites. MWCNTs/PC nanocomposites with different MWCNTs contents were prepared under different injection conditions. The mechanical property of nanocomposites was comparatively investigated. The results demonstrated that: the tensile property of the nanocomposites was slightly improved by MWCNTs content increasing; but as the MWCNTs contents went on to increase to 10wt%, the tensile strength and bending strength were obviously decreased about 35% and 47%, respectively, but the impact strength and hardness were increased. The center hardness of MWCNTs/PC nanocomposites was greater than the surface hardness. Besides, the changes on the mechanical properties of the nanocomposites were studies by changing the injection conditions. By Scanning Electron Microscopy (SEM) observation, the microstructure and morphology of nanocomposites were analyzed, revealing that the center of the nanocomposite distributed more MWNTs, and the injection conditions would affect the MWNTs’ dispersion in the matrix and the interfacial interaction between MWCNTs and PC.

Research about the Effect of Ultrasonic Impact on the Mechanical Property of Welded Cruciform Joint of P355NL1 Steel

2014 ◽  
Vol 644-650 ◽  
pp. 4748-4751
Author(s):  
Bo Lin He ◽  
Ying Xia Yu ◽  
Si Yong Lei ◽  
Jian Ping Shi
Keyword(s):  
Mechanical Property ◽  
Residual Stress ◽  
Grain Size ◽  
Compressive Residual Stress ◽  
Impact Machine ◽  
Ultrasonic Impact Treatment ◽  
Weld Toe ◽  
The Impact ◽  
Cruciform Joint ◽  
Scanning Electron

Surface treatment was carried out on the welded cruciform joint of P355NL1 steel by using the HJ-II-type ultrasonic impact machine. The ultrasonic impact current is 1.5A, the impact amplitude is 20 microns and ultrasonic impacting time is 5min. Tensile test was carried out for both treated specimen and un-treated specimen. The fracture observed with the scanning electron microscope of 6360LA type. The experimental results show that although the compressive residual stress can be obtained in the surface of weld toe area, and the grain size in the surface of welded cruciform joint can be refined, but the mechanical property of the welded cruciform joint of P355NL1 steel can not be improved through the ultrasonic impact treatment. The main reason is that the ultrasonic impact layer is only 70um, it is to thin to compared to the thickness of the specimen.

scholarly journals Investigation on strength properties of polymer modified concrete using glycoluril

2021 ◽  
Author(s):  
SKM. Pothinathan ◽  
M. Muthukannan ◽  
N. Selvapalam ◽  
S. Christopher Gnanaraj
Keyword(s):  
Mechanical Property ◽  
Flexural Strength ◽  
Acid Resistance ◽  
Strength Properties ◽  
The Other ◽  
Polymer Content ◽  
Conventional Concrete ◽  
Concrete Mix ◽  
Polymer Modified Concrete ◽  
The Impact

AbstractIn this study, an endeavor is made to discuss mainly the mechanism, use, and application of polymer modified concrete which is increasing in general fame due to its simplicity, ease of handling, proficiency, and agreeable outcomes. This work explores the impact of adding a new polymer named glycoluril on the mechanical property through the estimation of compression, tension, and flexural strength. Physical properties such as density, sorptivity, and acid resistance were studied to establish the durability of concrete. This examination additionally ponders the impact of polymer in concrete and polymer dosage. Series of concrete mix with 0%, 1%, 2%, 3%, and 4% glycoluril by the mass of binder were prepared, cured, and tested in 7 days and 28 days. Results indicate that there is no adjustment in the workability aspect, however, the improvement of strength factor in compression, tension, and flexure is recorded when compared with the conventional concrete. The experimental results show that by increasing the proportion of glycoluril, the strength of concrete increased up to 3% in addition. In the meantime, the 3% addition provided a higher outcome than the other blend. Further expanding the polymer content marginally decreased the strength. The outcome affirms that the utilization of new polymer in concrete will increase the desired property.

Study on Mechanical Property of Conch Powder Reinforced Polyethylene Composite

2012 ◽  
Vol 557-559 ◽  
pp. 286-290
Author(s):  
Zhi Hong Guo ◽  
Jia Wei Shi ◽  
Qun Shao ◽  
Pei Jie Lin ◽  
Yan Ping Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tensile Strength ◽  
High Tensile Strength ◽  
Frictional Loss ◽  
Practical Applications ◽  
Impact Performance ◽  
Polyethylene Composite ◽  
Maximum Value ◽  
The Impact

The impact performance of PE can be greatly enhanced by the use of functionalized conch powder, while maintaining high tensile strength thus giving this study high potentiality for its practical applications. The conch powder was treated by titanate coupling agent NDZ-201 before use and the influence of different proportions of conch powder on the mechanical properties of PE/conch powder composite is discussed in this article. The impact strength has a maximum value of 63.4kJ/m2 and the frictional loss records a minimum of 4.27×10-1mm3/(Nm)-1 and 42.2% lower than that of pure PE.

Mechanical response of the real tree root architecture under lateral load

2020 ◽  
Vol 50 (7) ◽  
pp. 595-607
Author(s):  
Johnatan Ramos-Rivera ◽  
Harianto Rahardjo ◽  
Daryl Lee Tsen-Tieng ◽  
Nong Xuefeng ◽  
Fong Yok King
Keyword(s):  
Root System ◽  
Static Loading ◽  
Root Architecture ◽  
Mechanical Response ◽  
Lateral Load ◽  
Soil System ◽  
System Architectures ◽  
Mechanical Responses ◽  
Loading Tests ◽  
The Impact

The impact of climate change on tree stability is often associated with a higher risk of windthrow due to higher frequency and greater magnitude of extreme climatic conditions. Higher lateral loads due to an increase in maximum wind and rainfall reduce tree anchorage because of a decrease in soil matric suction and consequently the overall strength in the system of trunk, root, and soil. This study compared the mechanical response of trees with different root architectures using static loading tests conducted in the field and numerical analysis of laser-scanned root systems. For this case, mature trees of Khaya senegalensis (Desr.) A. Juss., Samanea saman (Jacq.) Merr., and Syzygium grande (Wight) Wight ex Walp. were tested and analyzed. The root system models consisted of root system architectures obtained using 3-D laser scanning. A parametric analysis was conducted by varying the modulus of elasticity of the soil (Es) from 2.5 to 25 MPa, and the results were compared with those of the static loading tests to obtain the overall mechanical responses of the root–soil systems. The results showed important dependencies of the mechanical responses of the root–soil system on the root architecture in withstanding the lateral load. The numerical models also allowed estimation of the effective leeward and windward anchorage zones with different soil elastic moduli and rooting architectures to define the extent of the tree root protection zones.

A Study on Evaluation of Impact Strength of Adhesive Joints Subjected to Impact Shear Loadings

2008 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Toshimasa Nagai ◽  
Takeshi Iwamoto ◽  
Hideaki Kuramoto
Keyword(s):  
Impact Strength ◽  
Adhesive Joint ◽  
Static Loading ◽  
Split Hopkinson Pressure Bar ◽  
Shear Loading ◽  
Adhesive Joints ◽  
Stress Distributions ◽  
Adhesive Thickness ◽  
The Impact ◽  
Strength Of Adhesive Joints

Adhesive joints in mechanical structures are subjected to static loading as well as impact loading. It is desired for the adhesive joints to have sufficient strength under both static and impact loadings. A lot of studies on the adhesive joints and the joint strength subjected to static loading have been carried out and examined. A few research works on the adhesive joint subjected to dynamic loading have been done, however, it has not fully elucidated for applying the joints to important sections in mechanical structures. In this study, the impact strength of adhesive joints subjected to impact shear loading is investigated using modified split Hopkinson pressure bar (SHPB) apparatus. The shear strength of adhesive joint, in which a solid cylinder is bonded to a hollow cylinder by an adhesive, is determined from maximum applied shear stress. A commercial thermosetting epoxy adhesive is used in the experiments. At the same time, the stress distributions in the joints subjected to impact shear loading are simulated by the finite-element analyses (FEA). The effect of adhesive thickness is investigated experimentally and computationally. It is shown that the strength is greatly affected by the adhesive thickness and the effect on the stress distributions in the joint is discussed.

scholarly journals Investigation of layer height influencing the impact strength of polylactic acid (PLA)

2021 ◽  
Vol 15 (2) ◽  
pp. 76-83
Author(s):  
József Richárd Lennert ◽  
József Sárosi
Keyword(s):  
Mechanical Property ◽  
3D Printing ◽  
Impact Strength ◽  
Basic Material ◽  
3D Printer ◽  
Printing Technology ◽  
Layer Height ◽  
The Impact ◽  
Influential Parameters ◽  
Printing Time

The aim of this study is to investigate the effect of layer height used during 3D printing on the impact strength, their standard deviations, and the printing time by using UNI EN ISO 180 unnotched specimens manufactured by FDM 3D printing technology. Every specimen is made of PLA, which is the most basic material of the FDM printing technology by using the same 3D printer. In this study it plays a key role to find out whether the layer height can be used to optimize the researched mechanical property within an economical framework or not. What is more, the possibly observable tendencies and crucial influential parameters will be analysed as well.

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