scholarly journals Mechanical properties of pellets in compression

2016 ◽  
Vol 61 (Special Issue) ◽  
pp. S1-S8 ◽  
Author(s):  
Ľ. Kubík ◽  
V. Kažimírová
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Compressive Loading ◽  
Strain Curve ◽  
Stress And Strain ◽  
Sample Length ◽  
Maximum Point ◽  
Mechanical Parameters ◽  
Compression Force ◽  
Production Engineering

The paper deals with the evaluation of mechanical properties of the cylinder pellet samples. The pellets were made from hay by the granulating machine MGL 200 (Kovonovak) provided by the Department of Production Engineering, Slovak University of Agriculture in Nitra. The pellets were submitted to compressive loading. The compressive loading curves of dependencies of force on strain and force on time were realised by the test stand Andilog Stentor 1000. Certain mechanical parameters were determined, namely the diameter of the sample, length of the sample, force at 10% of strain, force in the first maximum of the force – strain curve, strain in the first maximum of the force – strain curve, modulus of elasticity, force in the inflex point of the force – time and force – strain curves and strain and stress in the inflex point of the force – time and force – strain curves. Significant correlations of the mechanical parameters were observed between the inflex point and the first maximum point of the loading curves. There were find out, the compression force, stress and strain in the inflex point significantly correlate with the force, stress and strain in the first maximum.

scholarly journals Study on the Mechanical Properties of Red Clay under Drying-Wetting Cycles

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Qi Yanli ◽  
MingZhou Bai ◽  
Hao Zhou ◽  
Hai Shi ◽  
Pengxiang Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Direct Shear Test ◽  
Shear Test ◽  
Strain Curve ◽  
Stress And Strain ◽  
Direct Shear ◽  
Guangxi Province ◽  
Red Clay ◽  
Plastic Hardening ◽  
The Relationship

To study the mechanical properties of red clay under repeated dry and wet cycle test conditions, in this paper, the disturbed red clay in an engineering area in Liuzhou, Guangxi Province, was taken as the research object. By artificially controlling different dry and wet cycles in the laboratory, a direct shear test and triaxial consolidation drainage test were carried out on the red clay samples after different dry and wet cycles. The stress-strain curve and change rule of corresponding c and φ values were obtained. The results showed that, in both the direct shear test and the triaxial test, the shear strength parameters of red clay decreased with an increase in the number of dry and wet cycles and the attenuation was most obvious during the first cycle. With an increase in the number of dry and wet cycles, the attenuation gradually decreased. The constitutive model of the deviatoric stress and strain curve of red clay under dry and wet cycles was a plastic-hardening type. By analyzing the variation in parameters in the P-H model, the relationship between c, φ, and the number of dry and wet cycles n was obtained. The results showed that the parameters had different degrees of attenuation with the action of dry and wet cycles. To explain the above rules, some samples under different drying-wetting cycles were selected for environmental electron microscope scanning, and appropriate assumptions were made based on the microstructure.

Experimental Setup for the Determination of Mechanical Solder Materials Properties at Elevated Temperatures

2010 ◽  
Vol 638-642 ◽  
pp. 3793-3798
Author(s):  
Wolfgang H. Müller ◽  
Holger Worrack ◽  
Jens Sterthaus
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Elevated Temperatures ◽  
Young's Modulus ◽  
Linear Optimization ◽  
Strain Curve ◽  
Stress And Strain ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Non Linear

The fabrication of microelectronic and micromechanical devices leads to the use of only very small amounts of matter, which can behave quite differently than the corresponding bulk. Clearly, the materials will age and it is important to gather information on the (changing) material characteristics. In particular, Young’s modulus, yield stress, and hardness are of great interest. Moreover, a complete stress-strain curve is desirable for a detailed material characterization and simulation of a component, e.g., by Finite Elements (FE). However, since the amount of matter is so small and it is the intention to describe its behavior as realistic as possible, miniature tests are used for measuring the mechanical properties. In this paper two miniature tests are presented for this purpose, a mini-uniaxial-tension-test and a nanoindenter experiment. In the tensile test the axial load is prescribed and the corresponding extension of the specimen length is recorded, both of which determines the stress-strain- curve directly. The stress-strain curves are analyzed by assuming a non-linear relationship between stress and strain of the Ramberg-Osgood type and by fitting the corresponding parameters to the experimental data (obtained for various microelectronic solders) by means of a non-linear optimization routine. For a detailed analysis of very local mechanical properties nanoindentation is used, resulting primarily in load vs. indentation-depth data. According to the procedure of Oliver and Pharr this data can be used to obtain hardness and Young’s modulus but not a complete stress-strain curve, at least not directly. In order to obtain such a stress-strain-curve, the nanoindentation experiment is combined with FE and the coefficients involved in the corresponding constitutive equations for stress and strain are obtained by means of the inverse method. The stress-strain curves from nanoindentation and tensile tests are compared for two mate-rials (aluminum and steel). Differences are explained in terms of the locality of the measurement. Finally, material properties at elevated temperature are of particular interest in order to characterize the materials even more completely. We describe the setup for hot stage nanoindentation tests in context with first results for selected materials.

scholarly journals Quality and Bending Properties of Scots Pine (Pinus Sylvestris L.) Sawn Timber

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1200
Author(s):  
Izabela Burawska-Kupniewska ◽  
Sławomir Krzosek ◽  
Piotr Mańkowski ◽  
Marek Grześkiewicz
Keyword(s):  
Mechanical Properties ◽  
Scots Pine ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Mechanical Parameters ◽  
Bending Properties ◽  
Characteristic Values ◽  
Sawn Timber ◽  
The Moment

The paper presents the partial research results of a mechanical properties study conducted on Scots pine from the Silesian Forestry Area in Poland. The scope of research included the visual strength grading of the timber according to the PN-D-94021:2013 standard, mechanical testing (according to EN 408:2012) and an attempt to assign visuals to the C strength classes. The EN 1912: 2012 standard assigns the visual sorting classes of individual wood species (according to national sorting standards) to the C strength classes introduced by the EN 338: 2018 standard. At the moment, this standard does not assign Polish visual sorting classes (KW, KS, and KG) to C strength classes. The obtained MOE (modulus of elasticity) and MOR (static bending strength) values were corrected according to the EN 384:2018 standard, and their characteristic values were later calculated. On this basis, we proposed a classification of the grading classes determined on the basis of PN-D-94021 into C classes described in EN 338:2018, which is necessary in the process of the transposition of Polish strength grades (KW, KS, KG, and Reject) and the qualification of them in line with EN 1912:2012. The calculated characteristic values of density, MOR and E0 (the modulus of elasticity parallel to the grain) allowed us to assign Polish visual grades KW, KS, and KG to C35, C30, and C20, respectively. The pine timber under research had high physical and mechanical parameters, which translated into high C classes to which the KW, KS, and KG timber categories were assigned.

scholarly journals Mechanical Properties of Soft Soil considering the Influence of Unloading Stress Paths

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Wei Huang ◽  
Junjie Li ◽  
Yuming Lu ◽  
Dongsheng Li ◽  
Yaqing Mou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Numerical Analysis ◽  
Soft Soil ◽  
Strain Curve ◽  
Friction Angle ◽  
Confining Pressure ◽  
Stress Path ◽  
Hyperbolic Function ◽  
Mechanical Parameters ◽  
Current Design

The mechanical properties of soft soil are crucial for the design and construction of underground space excavation; however, the current design and numerical analysis of underground spaces consider the loading mechanical parameters, ignoring the influence of the unloading stress path resulting in frequent construction accidents in practice. Here, soft soil in Shenzhen, China, is taken as the research subject, and a series of consolidated-undrained unloading tests are performed. First, K0 consolidation is conducted. Then, unloading tests are performed with different unloading ratios to simulate different unloading stress paths. The test results show that the soft soil deformation characteristics are closely related to the stress path and unloading ratio. Under different unloading ratios, soft soil will undergo compression deformation or rebound deformation. Under unloading conditions, the deviator stress-strain curve satisfies a hyperbolic function and can be normalized with the average consolidation confining pressure. With the increase in the unloading ratio, the initial tangent modulus first decreases and then increases, the cohesion decreases, and the internal friction angle does not change significantly. The loading mechanical parameters are not suitable for numerical calculation in unloading engineering. In this paper, more unloading paths are considered, such as UU1.0 and UU0.5. The results of the study provide a theoretical basis for the calculation of the numerical analysis of the soil body at different depths in rich soft soil pits.

scholarly journals Mechanical Properties of Wheat Grains at Compression

2021 ◽  
Vol 24 (4) ◽  
pp. 202-208
Author(s):  
Ľubomír Kubík ◽  
Monika Božiková ◽  
Viera Kažimírová
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Compressive Loading ◽  
Whole Grains ◽  
Failure Strength ◽  
Parallel Plates ◽  
Whole Grain ◽  
General Behaviour ◽  
Wheat Grains ◽  
Compressive Loads

Abstract Hook’s law for evaluation of the modulus of elasticity of wheat grains and its general behaviour under compressive loads were studied. Whole specimens were subjected to compressive loading between metal parallel plates. The mechanical properties of grains were determined in terms of average failure strengths of grain bran and whole grain; deformation; and modulus of elasticity. The mechanical properties of very dry grains of the winter wheat Triticum aestivum L. with the moisture content of 10.3% were studied. The failure strength of grain bran was 4.43 MPa at the deformation of 10.7%, and the failure strength of whole grains was 4.88 MPa at the deformation of 13.5%. The modulus of elasticity of grains was 43.67 MPa. The apparent energy density at bran failure strength was 0.261 MJ·m−3, and 0.470 MJ·m−3 on the level of grain failure strength of the whole grain. The bran border structure of central inner part of grains was studied using microscope digital sections of longitudinal cuts of the grains using the image computer processing method. The area proportion of starch and pericarp of the border parts of grains was studied to describe the border texture of central sections of grains.

Analysis on Plane and Ball Compression Behaviour of Spacer Fabric

2011 ◽  
Vol 332-334 ◽  
pp. 1049-1052
Author(s):  
Guang Kai Ji ◽  
Xiao Liu ◽  
Zhao Qun Du
Keyword(s):  
Strain Curve ◽  
Maximum Pressure ◽  
Stress And Strain ◽  
Compression Stress ◽  
Compression Force ◽  
Pressure Force ◽  
Compression Behaviour ◽  
Spacer Fabric ◽  
Plane Plate ◽  
Spherical Ball

In present paper, the compression force and strain curve for both plane plate and spherical ball compressions are conducted, where the compression stress and strain curve in plane plate compression is calculated and divided into three linear sections. Each linear region has corresponding compression modulus. In addition, three compression characters of both plate plane and spherical ball compressions are featured as compression work, maximum pressure/force and linear degree. Correlations between the three characters of compression property show that there exist high correlations between compression work and maximum pressure/force for plane plated and spherical ball compression. Moreover, effects of sample size and shape on compression properties are also conducted, and we find that there are no significant effects and the three compression characters are stable in both plane plate and spherical ball compression. Finally, the explicit formula derived in the Part I of this series for the spherical ball compression is used, and the ball compression force and strain curves are simulated based on the compression stress and strain curves based on plane plate compression tests. The comparing results between measured and theoretical results indicate that the theoretical model is effective to simulate ball compression behaviour of general knitted spacer fabrics. It is highly helpful in designing and predicting compression force of knitted spacer fabric for virtual processing of textile materials.

scholarly journals Evaluation of Mechanical Parameters of Pellets

2016 ◽  
Vol 64 (5) ◽  
pp. 1593-1601
Author(s):  
Ľubomír Kubík ◽  
František Adamovský ◽  
Viera Kažimírová
Keyword(s):  
Wheat Straw ◽  
Initial Stress ◽  
Modulus Of Elasticity ◽  
Compressive Loading ◽  
Mean Value ◽  
Mechanical Parameters ◽  
Mean Values ◽  
Rapeseed Straw ◽  
Strain Stress ◽  
Initial Force

The paper dealt with the evaluation of mechanical properties of the cylinder wheat straw, rapeseed straw and 50/50 % mixed wheat and rapeseed straw pellet samples. The pellets were made by the granulating machine MGL 200 (Kovonovak). The compressive loading curves of dependencies of stress on strain were realised by the test stand Andilog Stentor 1000 (Andilog Technologies, Vitrolles, France). Certain mechanical parameters were determined, namely the initial force (force at 10 % of compress strain), force in maximum of loading curve, strain in maximum of loading curve, initial stress (stress at 10 % of compression strain), stress in maximum of loading curve and modulus of elasticity. Mean value of the initial force was maximal for mixed straw pellet samples 52.49 N. Mean values of the initial force of the wheat straw samples and the rapeseed straw samples were smaller and almost identical 43.58 N and 43.12 N. Mean values of the initial stress of loading curve, of the wheat straw samples reached 1.46 MPa, the rapeseed straw samples reached value 1.40 MPa and the mixed straw samples reached value 1.63 MPa. Mean value of the force in maximum of loading curve was also maximal for mixed straw pellet samples 213.26 N. Mean values of the force in maximum of loading curve of the wheat straw samples reached 178.11 N. The rapeseed straw samples reached value 95.95 N and the mixed straw samples reached value 213.26 N. Mean values of the stress in maximum of loading curve, of the wheat straw samples reached 5.93 MPa, the rapeseed straw samples reached value 3.11 MPa and the mixed straw samples reached value 7.10 MPa Mean values of the modulus of elasticity, of the wheat straw samples reached 18.27 MPa, the rapeseed straw samples reached value 13.08 MPa and the mixed straw samples reached value 14.97 MPa. Significant correlations of the mechanical parameters pellet samples were observed among initial force and initial stress and modulus of elasticity. Significant correlations of force in maximum with stress and strain in the maximum were observed.

scholarly journals Experimental Research on the Mechanical Properties of Tailing Microcrystalline Foam Glass

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2048 ◽  
Author(s):  
Jinliang Bian ◽  
Wanlin Cao ◽  
Lin Yang ◽  
Cunqiang Xiong
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Foam Glass ◽  
Experimental Studies ◽  
Great Influence ◽  
Future Research ◽  
Stress And Strain ◽  
Light Weight ◽  
Foaming Agent ◽  
Strength Tests

Tailing microcrystalline foam glass (TMFG) is a building material that not only has the characteristics of light weight, fire resistance, and thermal insulation, but also has decorative applications. TMFG has a broad application prospect, but there has been little research on the macroscale mechanical properties of this material. In order to analyze TMFG basic mechanical properties, a series of experimental studies were carried out by performing the four-point flexural, shear, uniaxial compression, and splitting tensile strength tests. The research showed that the foaming agent (SiC) had a great influence on the mechanical properties of the material. With the reduction of the amount of SiC, the strength of the material and brittle failure increased. The microcrystalline decoration surface improved the flexural strength and compression strength of the tailing microcrystalline foam glass. The modulus of elasticity and the Poisson’s ratio are discussed, and a formula for the modulus of elasticity is proposed. Based on the analysis of the stress and strain curves, a constitutive model is proposed for the application of tailing microcrystalline foam glass and future research on this material.

A Study on Tensile Mechanical Properties of Bamboo Plywood

2011 ◽  
Vol 291-294 ◽  
pp. 1009-1014 ◽  
Author(s):  
Jian Han ◽  
Xi Tao Gao
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Tensile Stress ◽  
Elastic Deformation ◽  
Modulus Of Elasticity ◽  
Tensile Deformation ◽  
Tensile Modulus ◽  
Stress And Strain ◽  
Load Increase ◽  
Tensile Elastic Modulus

The tensile mechanical properties of bamboo mat and curtain plywood（for short bamboo plywood）were studied through “electrometric method”. It was proved that in the range of elastic deformation，the Poisson′s ratio and the elastic modulus of the bamboo plywood were not constant. The Poisson′s ratio of the bamboo plywood decreased nonlinearly with the load increase that Poisson′s ratio decreased markedly when the load was less than 1kN，and decreased gently when more than 1kN.The tensile elastic modulus of the bamboo plywood also increased nonlinearly with the load increase that the tensile modulus of elasticity increased drastically when the load was less than 800N，and increased less when exceeded 800N. In the process of loading，the tensile deformation、the tensile stress and strain all increased linearly with the load increase，and the tensile stress and strain both were linearly relevant to tensile deformation.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

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