scholarly journals The use of image analysis for determination of surface deterioration level of improved alumina based materials subjected to cavitation

2013 ◽  
Vol 45 (1) ◽  
pp. 97-105 ◽  
Author(s):  
M.M. Dimitrijevic ◽  
M. Dojcinovic ◽  
A. Devecerski ◽  
R. Jancic-Heinemann ◽  
T. Volkov-Husovic
Keyword(s):  
Mechanical Properties ◽  
Mass Loss ◽  
Cavitation Erosion ◽  
Surface Erosion ◽  
Resistant Material ◽  
Good Resistance ◽  
Erosion Rates ◽  
Set Up ◽  
Different Content

Alumina based specimens having different content of alumina based fibers were investigated for possible application as cavitation resistant material. Cavitation damages of the alumina based specimens were tested by the modified vibratory cavitation set up. Erosion rates were measured based on the method developed for metallic samples, mass loss was measured during the experiment. Surface erosion was determined during the experiment simultaneously to mass loss measurements. Image Pro Plus Program was applied for surface analysis during testing. Results indicate that investigated material exhibit excellent mechanical properties and very good resistance to cavitation erosion.

scholarly journals Determination of mechanical properties of soil under laboratory conditions

2014 ◽  
Vol 60 (Special Issue) ◽  
pp. S66-S69 ◽  
Author(s):  
V. Malý ◽  
M. Kučera
Keyword(s):  
Mechanical Properties ◽  
Penetration Depth ◽  
Measuring Device ◽  
Laboratory Conditions ◽  
Measuring Network ◽  
Set Up ◽  
Different Diameters ◽  
Different Levels ◽  
Properties Of Soil

This paper presents the mechanical properties of soil. In order to determine the properties of soil under laboratory conditions, a special measuring device was constructed, viz. a bevameter. Two types of soil with different levels of moisture were examined and their mechanical properties were determined. Measurements were taken of non-compressed soil. A measuring network was set up, consisting of measuring and recording devices. In the course of measuring, the force and penetration depth of the pressing plate were recorded simultaneously. Three different diameters of pressing plate were used, namely 38, 50 and 70 mm. The pressure on the contact area was calculated after completion of the measurements, and the relationships between pressure and penetration depth were presented graphically.

scholarly journals Degradation and erosion mechanisms of bioresorbable porous acellular vascular grafts: an in vitro investigation

2017 ◽  
Vol 14 (132) ◽  
pp. 20170102 ◽  
Author(s):  
Piyusha S. Gade ◽  
Keewon Lee ◽  
Blaise N. Pfaff ◽  
Yadong Wang ◽  
Anne M. Robertson
Keyword(s):  
Mechanical Properties ◽  
Mass Loss ◽  
Mechanistic Model ◽  
Vascular Grafts ◽  
Damage Function ◽  
Surface Erosion ◽  
Outer Diameter ◽  
In Vitro Investigation

A fundamental mechanism of in situ tissue regeneration from biodegradable synthetic acellular vascular grafts is the effective interplay between graft degradation, erosion and the production of extracellular matrix. In order to understand this crucial process of graft erosion and degradation, we conducted an in vitro investigation of grafts ( n = 4 at days 1, 4, 7, 10 each) exposed to enzymatic degradation. Herein, we provide constitutive relationships for mass loss and mechanical properties based on much-needed experimental data. Furthermore, we formulate a mathematical model to provide a physics-based framework for understanding graft erosion. A novel finding is that despite their porous nature, grafts lost mass exponentially via surface erosion demonstrating a 20% reduction in outer diameter and no significant change in apparent density. A diffusion based, concentration gradient-driven mechanistic model of mass loss through surface erosion was introduced which can be extended to an in vivo setting through the use of two degradation parameters. Furthermore, notably, mechanical properties of degrading grafts did not scale with mass loss. Thus, we introduced a damage function scaling a neo-Hookean model to describe mechanical properties of the degrading graft; a refinement to existing mass-dependent growth and remodelling (G&R) models. This framework can be used to improve accuracy of well-established G&R theories in biomechanics; tools that predict evolving structure–function relationships of neotissues and guide graft design.

scholarly journals Determination of the physical-mechanical properties of a permeable block

2021 ◽  
Vol 2139 (1) ◽  
pp. 012016
Author(s):  
H Y Jaramillo ◽  
J A Gómez-Camperos ◽  
N Quintero-Quintero
Keyword(s):  
Mechanical Properties ◽  
Polyethylene Terephthalate ◽  
Physical And Mechanical Properties ◽  
Normal Density ◽  
Fine Aggregate ◽  
High Permeability ◽  
Good Resistance ◽  
Standard Procedures ◽  
Concrete Blocks

Abstract This study aims to analyze the influence of the incorporation of crushed polyethylene terephthalate as a substitute for fine aggregate in percentages of 10%, 15%, and 20% for the elaboration of concrete blocks. The methodology used is experimental quantitative approach, where the influence of the addition of crushed polyethylene terephthalate as a substitute for fine aggregate for the elaboration of concrete blocks was analyzed to identify the variation in the physical and mechanical properties of samples elaborated under different substitutions and in this way compare with the Colombian standard procedures. The results found in this study indicated that the blocks with the different percentages of polyethylene terephthalate presented a good resistance compared to the block without polyethylene terephthalate, which presented a resistance of 8 MPa. The blocks with polyethylene terephthalate at 10%, 15%, and 20% presented an average resistance of 6.36 MPa, 3.58 MPa, and 4.63 MPa, respectively. Finally, it was analyzed that the blocks with 10% aggregate are waterproof with normal density. In comparison, the blocks with 15% and 20% polyethylene terephthalate have high permeability, with the ability to drain 1 liter of water in 105 s and 38 s, respectively.

scholarly journals The morphology of cavitation damage of heat-treated medium carbon steel

2006 ◽  
Vol 71 (8-9) ◽  
pp. 977-984 ◽  
Author(s):  
Marina Dojcinovic ◽  
Srdjan Markovic
Keyword(s):  
Carbon Steel ◽  
Cavitation Erosion ◽  
Medium Carbon Steel ◽  
Cavitation Damage ◽  
Medium Carbon ◽  
Erosion Rates ◽  
Hydraulic Machinery ◽  
Heat Treated ◽  
Set Up ◽  
Microscopy Techniques

In this paper the morphology of the cavitation damage to heat-treated medium carbon steel was analyzed. The experiments were conducted using a modified vibratory cavitation test set up. The erosion rates were measured by an analytical method. The morphology of the cavitation damage was studied by the scanning electron microscopy and optical microscopy techniques. The present work was aimed at understanding the cavitation erosion behavior of heat-treated medium carbon steel under laboratory conditions. The results indicate that the heat-treated medium carbon steel is not to be recommended for the production of hydraulic machinery parts exposed to high hydrodynamic intensity.

A discussion on deformation of solids by the impact of liquids, and its relation to rain damage in aircraft and missiles, to blade erosion in steam turbines, and to cavitation erosion - The resistance of materials to impact erosion damage

1966 ◽  
Vol 260 (1110) ◽  
pp. 193-203 ◽  
Keyword(s):  
Mechanical Properties ◽  
Mass Loss ◽  
Incubation Period ◽  
Turbine Blade ◽  
Cavitation Erosion ◽  
Steam Turbines ◽  
Microstructural Characteristics ◽  
Erosion Damage ◽  
The Impact ◽  
Impact Erosion

The behaviour of established and potential turbine blade and erosion shield materials subject to impact erosion by water droplets of controlled size has been investigated over a range of impact velocities up to 1040 ft./s. Both the topographical form and the microstructural characteristics of damage have been studied, and correlated with the conditions of the test and the mechanical properties and phase constitution of the materials. It has been found that the rate of erosion, as measured by mass loss, changes during the course of a test. An initial incubation period is generally followed, successively, by periods of increasing, constant, and then decreasing rates of erosion, possibly culminating in a second steady, but lower, rate of erosion.

scholarly journals Determination of degradation level during cavitation erosion of zircon based ceramic

2017 ◽  
Vol 49 (2) ◽  
pp. 175-185 ◽  
Author(s):  
Marko Pavlovic ◽  
Marina Dojcinovic ◽  
Sanja Martinovic ◽  
Milica Vlahovic ◽  
Zoran Stevic ◽  
...  
Keyword(s):  
Mass Loss ◽  
Thermal Imaging ◽  
Cavitation Erosion ◽  
Mechanical Shock ◽  
Cavitation Resistance ◽  
Material Degradation ◽  
Surface Degradation ◽  
Erosion Testing ◽  
Erosion Environment

Mechanical shock of zircon based ceramic induced by cavitation erosion testing was investigated in this study. Several parameters were followed in order to determine level of material degradation during the cavitation erosion testing. Mass loss was taken as a conventional criterion for material degradation, while the level of surface degradation was evaluated by image and thermal imaging analyses. Results show high cavitation resistance of zircon ceramics and their suitability when vigorous cavitation erosion environment is expected.

A New Model for the Equation Describing the Cavitation Mean Depth Erosion Rate Curve

2017 ◽  
Vol 68 (4) ◽  
pp. 894-898 ◽  
Author(s):  
Lavinia Madalina Micu ◽  
Ilare Bordeasu ◽  
Mircea Octavian Popoviciu
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Stainless Steels ◽  
Erosion Rate ◽  
Cavitation Erosion ◽  
Linear Variation ◽  
Erosion Rates ◽  
Supplementary Term ◽  
The Mean ◽  
Experimental Values

Paper present a new relation describing the curve MDER(t) which mediates the experimentally obtained values of the mean depth erosion rates. These curves are used to characterize the cavitation erosion behavioor of materials tested in the Cavitation Laboratory of Timisoara Polytechnic University. Practically the new relation is an improvement of the analytical model established in 2004 by Bordeasu and coworkers, by introducing a supplementary element, which take into consideration the shape of the zone in where the cavitation erosion rate became stable and has linear variation. These addition allow increasing the approximation of the experimental values and also putting into evidence the tiny differences between different materials (various types of stainless steels, highly alloyed bronzes etc.) which till now were considered with similar resistance. Thus, the supplementary term allow a better differentiation resulting from the chemical composition, the structure and the mechanical properties.

A Study on Cavitation Erosion Behavior of Different Metals in Biomass Fuel/Diesel Blend

2013 ◽  
Vol 1 (2) ◽  
pp. 14-21
Author(s):  
Huiqiang Yu ◽  
Hu Wang ◽  
Hengzhou Wo ◽  
Yufu Xu ◽  
Xianguo Hu
Keyword(s):  
Mass Loss ◽  
Cavitation Erosion ◽  
Pure Copper ◽  
Optical Microscope ◽  
Biomass Fuel ◽  
Erosion Behavior ◽  
Erosion Rates ◽  
Before And After ◽  
Loss Method ◽  
Surface Morphologies

The cavitation erosion behavior of different metals, such as pure copper (Cu), steel GCr15 (ASTM A295) and stainless steel 1Cr18Ni9Ti (ASTM A276 321), in the emulsified biomass fuel/diesel (10wt% biomass fuel in blend with diesel fuel) was investigated by using a magnetostrictive-induced cavitation vibratory apparatus. The morphology of surface was observed by optical microscope and scanning electron microscope, and the cavitation erosion rates of three metals were evaluated by mass loss method. The surface compositions after cavitation erosion were analyzed by energy-dispersive X-ray spectroscopy. The experimental results showed that the surface morphologies and elements of Cu and GCr15 were changed greatly before and after cavitation erosion in the emulsified biomass fuel/diesel blend, as contrast to 1Cr18Ni9Ti. The degree order of cavitation erosion among three metals was Cu, GCr15 and 1Cr18Ni9Ti, because that the anti-corrosion effect of 1Cr18Ni9Ti played a great role in the mass loss by cavitation erosion.

scholarly journals Constructing better roads with asphalt rubber

2015 ◽  
Vol 4 (2) ◽  
pp. 23-52 ◽  
Author(s):  
Jorge C. Pais ◽  
Liseane P. Thives ◽  
Paulo A. A. Pereirâ ◽  
Glicério Trichês
Keyword(s):  
Mechanical Properties ◽  
Laboratory Tests ◽  
Permanent Deformation ◽  
Asphalt Mixture ◽  
Good Resistance ◽  
Rubber Mixture ◽  
Wet Process ◽  
Asphalt Rubber ◽  
Prolonged Fatigue

Abstract Brazilians mixtures containing asphalt rubber were evaluated by mechanical laboratory tests. A conventional mixture with asphalt CAP-50/70 was produced as a mixture control. With the aim of compare the Brazilians mixtures performance, a Portuguese asphalt rubber mixture was tested as well. The testing set involved the determination of the mechanical properties, fatigue and permanent deformation, of asphalt rubber produced by wet process through two different systems: continuous blend and terminal blend. The asphalt rubber morphology was evaluated in order to determine the compatibility of the systems. The asphalt rubber mixtures exhibit good resistance to permanent deformation and prolonged fatigue life in relation to mixture control. Therefore it is concluded that the application of asphalt rubber alters the characteristics of asphalt mixture in a very beneficial way.

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