Investigation of Relationship between Instrumented Indentation Nominal Hardness and Reduced Elastic Modulus with Large Apex Angle Indenter

2012 ◽  
Vol 198-199 ◽  
pp. 193-196
Author(s):  
De Jun Ma ◽  
Jun Hong Guo ◽  
Wei Chen ◽  
Zhong Kang Song
Keyword(s):  
Elastic Modulus ◽  
Measurement Error ◽  
Apex Angle ◽  
Instrumented Indentation ◽  
Included Angle ◽  
Cube Corner ◽  
Order Polynomial ◽  
Strength Material ◽  
Relationship Of ◽  
The Relationship

Based on dimensional analysis, finite element numerical calculation is undertaken on elastic–plastic solids to investigate the relationship between instrumented indentation nominal hardness Hn and reduced elastic modulus Er for three different apex angle indenters. The half-included angles of axisymetric conical indenter models are 62.9°, 70.3°and 85.566° which are corresponding to the real indenters of cube corner indenter with 60° face angle, Berkovich indenter with 65.27° face angle and cube corner indenter with 85° face angle, respectively. The relationship between a nominal hardness/reduced elastic modulus (Hn/Er) and elastic work/total indentation work (We/Wt) is established with a sixth-order polynomial form for each apex angle indenter. For rigid indenter of instrumented indentation model, reduced elastic modulus Er=1/[(1+v2)/E], where E and v are elastic modulus and Poisson’s ratio of the indented material. Therefore, Hn/Er–We/Wt relationship can be used to give estimates of E. Accuracy estimation for the each relationship of each half-included angle indenter shows that the large half-included angle of 85.566° gives better Er measurement error of +11.56% for a low yield strength material(e.g., materials for which σy=100MPa, n=0 and E=200GPa), while for the smaller half-included angle of 62.9° or 70.3° indenter, the measurement error is > ±12.74%. The research in this paper confirms that Hn/Er–We/Wt relationship of large apex angle indenter such as 85.566° half-included angle is recommended to be used for estimating the elastic modulus E of indented material.

Research on the Effect of Concentration and Type of De-Icing Salt on Concrete Salt-Scaling

2012 ◽  
Vol 450-451 ◽  
pp. 14-20
Author(s):  
Qiang Li ◽  
Zhi Yun Zhou
Keyword(s):  
Elastic Modulus ◽  
Compressive Loading ◽  
Peak Stress ◽  
Test Results ◽  
Reasonable Explanation ◽  
Salt Scaling ◽  
Relationship Of ◽  
The Relationship

To study the effect of concentration and type of de-icing salt on salt scaling based on the mechanism of glue spaling proposed by John J. Valenza II and George W. Scherer, the de-icing solution of NaCI andCaCI2 on the concentration of 1%、3%、5% and 7% were frozen into brine ice . Order to obtain the relationship of elastic modulus between the type and concentration of de-icing ,all brine ice specimens were tested under uni-axial compressive loading. The test results show: with the increase of concentration, the elastic modulus and peak stress of bring ice were decreased;when the same concentration ,the elastic modulus and peak stress of NaCl brine ice were higher than CaCI2.Based on the test results ,a reasonable explanation of the following phenomenon were given:The different type of de-icing salt all can lead to salt scaling of concrete;when the concentration of de-icing salt is moderate,it is will occur the most serious salt scaling.

The Influence to Modal Parameters of Retaining Wall by the Elastic Modulus of Soil

2011 ◽  
Vol 90-93 ◽  
pp. 3161-3165
Author(s):  
Li Biao Liu ◽  
Yong Xing Zhang ◽  
Jian Gong Chen
Keyword(s):  
Elastic Modulus ◽  
Soil Compaction ◽  
Retaining Wall ◽  
Numerical Test ◽  
Three Dimensional ◽  
Modal Parameters ◽  
Vibration Characteristic ◽  
Main Factors ◽  
Relationship Of ◽  
The Relationship

The characteristic of soil is one of the main factors that influence the modal parameters of retaining wall. This paper analyzes the influence to modal parameters of retaining wall by the elastic modulus of soil. Due to the complexity of the interaction of soil and retaining wall and based on the three-dimensional numerical test, dynamic response signals of retaining wall are obtained, processing of which and identification of modal parameters lead to the modal parameters of retaining wall. Lastly, vibration characteristic, frequency characteristic and the relationship of frequency and elastic modulus are also obtained.Therefore, the real elastic modulus of soil is gained by response signals in practical projects, and the degree of soil compaction can be pre-judged.

scholarly journals Ketidakberdayaan dan Perilaku Bunuh Diri: Meta-Analisis

2016 ◽  
Vol 24 (2) ◽  
Author(s):  
Tience Debora Valentina ◽  
Avin Fadilla Helmi
Keyword(s):  
Measurement Error ◽  
Suicidal Behavior ◽  
Suicide Attempts ◽  
Sampling Error ◽  
Meta Analysis ◽  
Analysis Study ◽  
The World ◽  
Relationship Of ◽  
Suicidal Ideas ◽  
The Relationship

The incidence of suicide increases in Indonesia and around the world that encourage the growing of research on suicidal behavior. Hopelessness recognized as a strongly predictor of suicidal behavior, including suicidal ideas and suicide attempts (Beck, Brown, Berchick, Stewart, & Steer, 1990; Reinecke and Franklin-Scott, 2005). However, the empirical results show the correlation between hopelessness and suicidal behavior seem to be less consistent. The purpose of this study is to determine the relationship of hopelessness and s uicidal behavior through the study of meta-analysis. There are 27 studies are including in this meta-analysis study. Two artifacts allow for correction in these study are sampling error and measurement error. The result shows that the correlation of hopele ssness and suicidal behavior is 0.360, with the confidence level is 95%

Temperature Dependence of Reaction Rate in the Oxidation of Dafosi Coal

2013 ◽  
Vol 316-317 ◽  
pp. 987-990 ◽  
Author(s):  
Xiao Xing Zhong ◽  
Guo Lan Dou ◽  
Yun Chen ◽  
De Ming Wang
Keyword(s):  
Reaction Rate ◽  
Spontaneous Combustion ◽  
Arrhenius Equation ◽  
Small Interval ◽  
Coal Spontaneous Combustion ◽  
Third Order ◽  
Coal Analysis ◽  
Order Polynomial ◽  
Relationship Of ◽  
The Relationship

Adiabatic self-heating tests had been conducted on Dafosi coal. Analysis of the relationship of temperature and reaction rate revealed that the dependence of coal sample temperature on reaction rate can be described by a third order polynomial from 40°C up to 155°C. But at a small interval of temperature, the reaction rate still conforms to the Arrhenius kinetic model. When Arrhenius equation is used to solve the kinetic parameters of the coal spontaneous combustion, the coal temperature should be processed in segment.

scholarly journals Effect of Alloying Additions on Microstructure, Mechanical and Magnetic Properties of Rapidly Cooled Bulk Fe-B-M-Cu (M = Ti, Mo and Mn) Alloys

2021 ◽  
Author(s):  
Mariusz Hasiak ◽  
Marzena Tkaczyk ◽  
Amadeusz Łaszcz ◽  
Jacek Olszewski
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Magnetic Properties ◽  
Elastic Modulus ◽  
Instrumented Indentation ◽  
Soft Magnetic ◽  
Alloying Additions ◽  
Transmission Electron ◽  
Wide Range ◽  
The Relationship

AbstractThe influence of alloying additions on the microstructure, mechanical, and magnetic properties of bulk Fe79B20Cu1, Fe79B16Ti4Cu1, Fe79B16Mo4Cu1 and Fe79B16Mn4Cu1 (at. pct) alloys was investigated. Nanocrystalline samples in the form of 3 mm rods were prepared directly by suction casting without additional heat treatment. Mössbauer spectroscopy, transmission electron microscopy and scanning electron microscopy studies confirmed that the investigated alloys consist α-Fe and Fe2B nanograins embedded in an amorphous matrix. The addition of alloying elements, such as Ti, Mo and Mn to Fe79B20Cu1 alloy increases the amount of amorphous phase and decreases the presence of Fe2B phase in all examined alloys. The mechanical properties of the samples, such as hardness, elastic modulus, and elastic energy ratio, were analysed by an instrumented indentation technique performed on a 12 × 12 nanoindentation grid. These tests allowed to characterise the mechanical properties of the regions observed in the same material. For the Fe79B20Cu1 alloy, the hardness of 1508 and 1999 HV, as well as Young’s modulus of 287 and 308 GPa, were estimated for the amorphous- and nanocrystalline-rich phase, respectively. The addition of Ti, Mo, and Mn atoms leads to a decrease in both hardness and elastic modulus for all regions in the investigated samples. Investigations of thermomagnetic characteristics show the soft magnetic properties of the studied materials. More detailed studies of magnetisation versus magnetic field curves for the Fe79B20−xMxCu1 (where x = 0 or 4; M = Ti, Mo, Mn) alloy, recorded in a wide range of temperatures, followed by the law of approach to magnetic saturation revealed the relationship between microstructure and magneto-mechanical properties.

Measurement Error of Left-Turn Vehicle Trajectory by Video Detection

2013 ◽  
Vol 401-403 ◽  
pp. 1068-1073
Author(s):  
Bo Hang Liu ◽  
Xiao Xia Liu ◽  
Shi Jie Zhang
Keyword(s):  
Measurement Error ◽  
Research Field ◽  
Left Turn ◽  
Theoretical Support ◽  
Detection Technology ◽  
Video Detection ◽  
Transverse Distance ◽  
Vehicle Trajectory ◽  
Relationship Of ◽  
The Relationship

The video detection technology is a very active branch in the research field of machine vision, and the detection of vehicle trajectory by the stationary camera has become more and more important. However, there is little research on the measurement error of left-turn vehicles trajectory.This paper not only studies the relationship between the measurement error and longitudinal distance; but also relationship of measurement error and transverse distance. Their mathematical models are constructed and each of the variables in the models is analyzed. Then in the case analysis of certain intersection, the experimental results have shown that the proposed funtions can describe the relationship between measurement error and the parameters. It can provide the theoretical support for the measurement error problems of obtaining trajectory by video detection.

scholarly journals Experimental study of the correlation between the elastic modulus of polymer composite materials and the velocity of ultrasonic waves

2020 ◽  
Vol 329 ◽  
pp. 02031
Author(s):  
Dmitrii Chulkov ◽  
Alexander Terekhin ◽  
Alexander Dumansky ◽  
Maxim Tipikin
Keyword(s):  
Experimental Study ◽  
Elastic Modulus ◽  
Composite Materials ◽  
Polymer Composite ◽  
Phenol Formaldehyde ◽  
Ultrasonic Waves ◽  
Polymer Composite Materials ◽  
Significant Regression ◽  
Relationship Of ◽  
The Relationship

This article presents the results of an experimental study of the relationship of acoustic parameters (propagation velocity) of ultrasonic waves with elastic characteristics (elastic modulus) of polymer composite materials. Significant regression dependences of the correlation between the velocity of ultrasonic won and the modulus of elasticity of a composite material based on fiberglass with an epoxy and phenol-formaldehyde binder have been constructed.

Experimental Study on the Mechanical Properties of Rubber Concrete

2014 ◽  
Vol 915-916 ◽  
pp. 685-689 ◽  
Author(s):  
Hong Quan Sun ◽  
Wen Hui Zhou ◽  
Chao Yi Wei
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Substitution Rate ◽  
Mechanical Performance ◽  
Replacement Rate ◽  
Conventional Concrete ◽  
Rubber Powder ◽  
Axial Compressive Strength ◽  
Relationship Of ◽  
The Relationship

With the methods of studying conventional concrete mechanical performance, the influence of concrete performance on the rubber powder replacement rate is investigated. Based on the test data, the relationship of between the elastic modulus and the rubber powder replacement rate is fitted. The results show that the concrete slump decreases with the rubber substitution rate increasing. The compressive strength of the cube of the concrete, the axial compressive strength and the elastic modulus go down in different degree with the increment of the rubber substitution rate.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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