scholarly journals The Effect of Fatigue Test on the Mechanical Properties of the Cellular Polyurethane Mats Used in Tram and Railway Tracks

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4118
Author(s):  
Juliusz Sołkowski ◽  
Jarosław Górszczyk ◽  
Konrad Malicki ◽  
Dariusz Kudła
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Mechanical Performance ◽  
Mechanical Stability ◽  
Traffic Noise ◽  
Cyclic Hardening ◽  
Fatigue Loading ◽  
Practical Significance ◽  
Mechanical Parameters ◽  
Railway Tracks

The use of modern synthetic materials is an important element in the development of railway tracks. Their use is a response to the growing requirements regarding the durability of structures and environmental protection against traffic noise and vibrations. In this paper, the results of the laboratory tests of selected mechanical properties of cellular polyurethane (PUR) mats which are applied in tram and railway tracks are presented in this study. The aim of the research was to determine the effect of fatigue loading on the mechanical performance of polyurethane mats. A series of samples made of two types of materials with different pore structures were tested. Static and fatigue laboratory tests were carried out on a specially prepared test stand. The values of selected mechanical parameters (the vertical static bedding modulus, the vertical dynamic bedding modulus, and the loss factor) were evaluated. The results of laboratory tests and analyses showed a significant influence of high-cycle fatigue loading on the values of mechanical parameters of the tested mats, which were quantified as a result of the study. For both types of materials, the phenomenon of cyclic hardening was observed. Additionally, for one of the materials, an undesired dynamic creep phenomenon was observed. It was also shown that the pore structure of polyurethane influences the mechanical performance of the mats. Therefore, the findings of the research may have practical significance for the quality evaluation of such materials, especially in the context of their durability and mechanical stability under real loading conditions.

Influence of Dispersed Reinforcement on the Physico-Mechanical Properties of the SFRC

2017 ◽  
Vol 755 ◽  
pp. 75-81 ◽  
Author(s):  
Tereza Komárková ◽  
Jaromír Láník ◽  
Petr Dvořák
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Steel Fiber ◽  
Fresh Concrete ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Mechanical Parameters ◽  
Steel Fiber Reinforced Concrete ◽  
The Individual ◽  
Building Practice

The article deals with steel fiber reinforced concrete (SFRC), specifically with its physical mechanical parameters which influence both design and reliable behavior of the building material in structures. The resulting physical mechanical properties of the SFRC depend on the properties of the individual components and also on their quantity. In the building practice, a common dosing of steel fibers that are added into fresh concrete mixture is ranging between 0.5% and 2%. The paper also describes the methodology of certain laboratory tests suitable for SFRC and the ways of data evaluation. The experiments proved a substantial influence of the quantity of steel fibers in the individual mixtures to the resulting mechanical properties.

The Impact of Corrosion on the Mechanical Behavior of Bolt

2010 ◽  
Vol 168-170 ◽  
pp. 408-411
Author(s):  
Xiao Yong Li
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Corrosion Test ◽  
Laboratory Tests ◽  
Structural Integrity ◽  
Mechanical Performance ◽  
Rock Bolt ◽  
Before And After ◽  
The Impact ◽  
Strength And Ductility

Corrosion is a negative contributor on the structural integrity of rock bolt and leads to degradation of the mechanical properties of steel rock bolt. Exposure to chloride, seawater, salt and saltwater and deicing chemical environments influences rock bolt and weakens it. In order to evaluate the influence of corrosion and the size of the steel on the mechanical properties of rock bolt, an experimental investigation was conducted on rock bolt whose rebar is 8, 12, 16, and 18 mm diameter, and which were artificially corroded for 10, 20, 30, 45, 60, 90, and 120 days. By the simulation corrosion test of loaded and unloaded bolts in Na2SO4 solution, the relation curves of the mechanical performance with the corrosive conditions and the corrosion time are given. The mechanical performance is compared between these two types of bolts. At the same time, the influential trend of the load on the mechanical performance of the corroded bolt is analyzed. The laboratory tests suggest that corrosion duration and rebar size had a significant impact on the strength and ductility degradation of the specimens. after being corroded in Na2SO4 solution, both the ultimate bearing capacity and the maximal tensility of loaded bolt decrease far more than those of unloaded bolt, and the endurance and service life of loaded bolt will also be shortened much more severely. The tensile mechanical properties before and after corrosion indicated progressive variation and drastic drop in their values.

scholarly journals High electrochemical and mechanical performance of zinc conducting-based gel polymer electrolytes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Isala Dueramae ◽  
Manunya Okhawilai ◽  
Pornnapa Kasemsiri ◽  
Hiroshi Uyama
Keyword(s):  
Mechanical Properties ◽  
Ionic Conductivity ◽  
Polymer Electrolytes ◽  
Zinc Acetate ◽  
Mechanical Performance ◽  
Mechanical Stability ◽  
Morphological Properties ◽  
Zinc Salt ◽  
Gel Polymer Electrolytes ◽  
Minimum Requirement

AbstractZinc ionic conducting-based gel polymer electrolytes (GPEs) were fabricated from carboxymethyl cellulose (CMC) and three different zinc salts in a mass ratio ranging within 0–30 wt%. The effects of zinc salt and loading level on the structure, thermal, mechanical, mechanical stability, and morphological properties, as well as electrochemical properties of the GPEs films, were symmetrically investigated. The mechanical properties and mechanical stability of CMC were improved with the addition of zinc acetate, zinc sulphate, and zinc triflate, approaching the minimum requirement of a solid state membrane for battery. The maximum ionic conductivity of 2.10 mS cm−1 was achieved with the addition of 15 wt% zinc acetate (ZnA), GPEA15. The supported parameters, indicating the presence of the amorphous region that likely supported Zn2+ movement in the CMC chains, were clearly revealed with the increase in the number of mobile Zn2+ carriers in FT-IR spectra and the magnitude of ionic transference number, the decrease of the enthalpy of fusion in DSC thermogram, and the shifting to lower intensity of 2θ in XRD pattern. The developed CMC/ZnA complex-based GPEs are very promising for their high ionic conductivity as well as good mechanical properties and the ability for long-term utilization in a zinc ion battery.

scholarly journals New Approach to Optimize Mechanical Properties of the Immiscible Polypropylene/Poly (Ethylene Terephthalate) Blend: Effect of Shish-Kebab and Core-Shell Structure

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1094 ◽  
Author(s):  
Yingxiong Wang ◽  
Dashan Mi ◽  
Laurens Delva ◽  
Ludwig Cardon ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shell Structure ◽  
Mechanical Performance ◽  
Practical Significance ◽  
Core Shell ◽  
New Approach ◽  
Poly Ethylene Terephthalate ◽  
Spherical Core ◽  
Core Shell Structure ◽  
Poly Ethylene

Improving the mechanical properties of immiscible PP/PET blend is of practical significance especially in the recycling process of multi-layered plastic solid waste. In this work, a multi-flow vibration injection molding technology (MFVIM) was hired to convert the crystalline morphology of the PP matrix from spherulite into shish-kebab. POE–g–MA was added as compatibilizer, and results showed that the compatibilization effect consisted in the formation of a core-shell structure by dispersing the POE–g–MA into the PP matrix to encapsulate the PET. It was found that the joint action of shish-kebab crystals and spherical core-shell structure enabled excellent mechanical performance with a balance of strength and toughness for samples containing 10 wt % PET and 4 wt % POE–g–MA, of which the yield strength and impact strengths were 50.87 MPa and 13.71 kJ/m2, respectively. This work demonstrates a new approach to optimize mechanical properties of immiscible PP/PET blends, which is very meaningful for the effective recycling of challenging plastic wastes.

scholarly journals Exploratory Experimental Study on the Mechanical Properties of Granite Subjected to Cyclic Temperature and Uniaxial Stress

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2061
Author(s):  
Guokai Zhao ◽  
Yaoqing Hu ◽  
Peihua Jin
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Mechanical Stability ◽  
Strain Curve ◽  
Cyclic Hardening ◽  
Uniaxial Stress ◽  
Stress Strain ◽  
Upper Limit ◽  
Cyclic Temperature ◽  
Granite Samples

This paper investigates the variation of mechanical properties of granite during temperature and stress cycling, which is an important part of evaluating the long-term thermal and mechanical stability of thermal energy storage. Cyclic temperature and loading tests were conducted where the upper limit of cyclic temperature was 100–600 °C, and the upper stress limits were 70% and 85% of the average uniaxial compressive strength (UCS) at the corresponding temperature. The response of stress–strain characteristics of the granite samples to changes in temperature, and cyclic load upper limit, while the number of temperature and loading cycles was comprehensively analyzed. The results show that the temperature and stress cycles have significant effects on the mechanical properties of granite (i.e., stress–strain curve, strength, elastic modulus, and deformation). The elastic modulus of the sample during loading increases gradually. The strain corresponding to the upper loads of the granite samples decreases with an increasing number of cycles. Additionally, the UCS of samples after 10 cycles at 70% loading stress is greater than that at 85% loading stress. The mechanical properties of samples change dramatically during the first and second cycles at 85% loading stress, whereas at 70% loading stress, the mechanical properties change gradually in the first few cycles, and then tend to stabilize. Cyclic hardening is observed at temperatures below 500 °C, where post cyclic UCS is greater than the uncycled average UCS. This phenomenon requires further research.

An analysis of the transport properties and mechanical stability of rapidly solidified Al-Sb alloy

2015 ◽  
Vol 10 (2) ◽  
pp. 2663-2681
Author(s):  
Rizk El- Sayed ◽  
Mustafa Kamal ◽  
Abu-Bakr El-Bediwi ◽  
Qutaiba Rasheed Solaiman
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Melt Spinning ◽  
Elastic Moduli ◽  
Mechanical Stability ◽  
Microstructural Analysis ◽  
Alloy System ◽  
Antimony Content ◽  
The Stability ◽  
Rapidly Solidified

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as melt–spun ribbons  as a function of antimony content .The stability  of these structures has  been  related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition.  The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes. 

LABORATORY TESTS OF THE PHYSICAL-MECHANICAL PROPERTIES OF MATERIALS FOR REMEDIAL JOBS

2020 ◽  
pp. 58-63
Author(s):  
M.A. Druzhinin ◽  
◽  
G.V. Okromelidze ◽  
O.V. Garshina ◽  
I.A. Kudimov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Mechanical Properties Of Materials ◽  
Properties Of Materials

Weldability - Behavior of Welded Reinforcement

2019 ◽  
Vol 70 (10) ◽  
pp. 3469-3472
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Mechanical Characteristics ◽  
Mechanical Performance ◽  
Current Work ◽  
Carbon Equivalent ◽  
Work Process ◽  
Ultimate Limit

Weldability involves two aspects: welding behavior of components and safety in operation. The two aspects will be reduced to the mechanical characteristics of the elements and to the chemical composition. In the case of steel reinforcing rebar’s, it is reduces to the percentage of Cech(carbon equivalent) and to the mechanical characteristics: the yielding limit, the ultimate limit, and the elongations which after that represent the ductility class in which the re-bars is framed. The paper will present some types of steel reinforcing rebar’s with its mechanical characteristics and the welding behavior of those elements. In the current work, process-related behavior of welded reinforcement, joint local and global mechanical properties, and their correlation with behavior of normal reinforcement and also the mechanical performance resulted in this type of joints. Keywords: welding behavior, ultimate limit, reinforcing rebar’s

The Sintering Behaviour and Mechanical Properties of Hydroxyapatite - Based Composites for Bone Tissue Regeneration

2018 ◽  
Vol 69 (5) ◽  
pp. 1272-1275 ◽  
Author(s):  
Camelia Tecu ◽  
Aurora Antoniac ◽  
Gultekin Goller ◽  
Mustafa Guven Gok ◽  
Marius Manole ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tricalcium Phosphate ◽  
Cosmetic Surgery ◽  
Mechanical Stability ◽  
Raw Materials ◽  
Oyster Shell ◽  
Bone Tissue Regeneration ◽  
Sintering Behavior ◽  
Bovine Bone ◽  
Human Teeth

Bone reconstruction is a complex process which involves an osteoconductive matrix, osteoinductive signaling, osteogenic cells, vascularization and mechanical stability. Lately, to improve the healing of the bone defects and to accelerate the bone fusion and bone augmentation, bioceramic composite materials have been used as bone substitutes in the field of orthopedics and dentistry, as well as in cosmetic surgery. Of all types of bioceramics, the most used is hydroxyapatite, because of its similar properties to those of the human bone and better mechanical properties compared to b-tricalcium phosphate [1]. Currently, the most used raw materials sources for obtaining the hydroxyapatite are: bovine bone, seashells, corals, oyster shell, eggshells and human teeth. There are two common ways to obtain hydroxyapatite: synthetically and naturally. Generally, for the improvement of the mechanical properties and the structural one, hydroxyapatite is subjected to the sintering process. Considering the disadvantages of hydroxyapatite such as poor biodegradation rate, b-TCP has been developed, which has some disadvantages too, such as brittleness. For this reason, the aim of this study is to look into the effect of adding magnesium oxide on the sintering behavior, the structure and the mechanical properties of the hydroxyapatite-tricalcium phosphate composites.

Study of Rheological Properties of Modified Concrete Mixtures at Vibration

2019 ◽  
Vol 968 ◽  
pp. 96-106
Author(s):  
Oleksandr Pshinko ◽  
Olena Hromova ◽  
Dmytro Rudenko
Keyword(s):  
Mechanical Properties ◽  
Rheological Properties ◽  
Physical Nature ◽  
Concrete Mixture ◽  
Practical Significance ◽  
Vibration Displacement ◽  
Concrete Mixtures ◽  
Variable Quantity ◽  
Vibration Compaction ◽  
Mechanism Of Interaction

Study of rheological properties of concrete mixtures based on modified cement systems in order to determine process parameters. Methodology. To study structural-mechanical properties of modified concrete mixtures of different consistency at their horizontal vibrating displacement an oscillatory viscometer was designed. Results. The optimization of the process of vibration displacement of concrete mixtures with the specification of parameters of vibration impacts taking into account structural-mechanical properties of the mixture is performed. It has been established that the viscosity of the modified cement system of the concrete mixture is a variable quantity, which depends on the parameters of the vibration impacts. Scientific novelty. The mechanism of interaction of the modified concrete mixture with the form and the table vibrator during its vibration compaction is determined. On the basis of this, a model of concrete laying process control is proposed, that allows to predict the ability to form a dense concrete structure. Practical significance. Disclosed physical nature of the process of vibrating displacement of modified concrete mixtures using the principles of physical-chemical mechanics of concrete allows reasonably choose the best options for vibration impacts.

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