Wyniki wyszukiwania - BazTech

1

A new approach to determining the elastic modulus of structural materials

Zhigun Valery, Chatys Rafał, Plume Egils

Composites Theory and Practice

|

2025

|

R. 25, nr 3

217--225

EN

Stiffness characteristics are often decisive in the choice of material for structural parts. At the same time, the process of their determination for anisotropic materials does not fully satisfy the requirements in terms of reliability and reproducibility. This work is devoted to the development of an approach for determining the moduli of elasticity. An analysis of the Timoshenko approaches developed to estimate the shear component of deflection in transverse bending is presented. The drawbacks preventing their use as a basis for modern methods of determining the elastic components of structural materials are noted. An approach for determining the elastic moduli is proposed, the basis of which are the maximum values of deflections and angles of rotation of the cross-sections of a specimen under three-point transverse bending. The relationship between angular and linear displacements under the considered type of loading is established, which allows stable and reliable values of elasticity moduli to be obtained from the data of angular displacements. The acceptability of the proposed approach for determining the elastic moduli of both isotropic materials and composites is shown.

2

Basic set of experiments for determination of mechanical properties of sand

Sawicki A., Mierczyński J., Świdziński W.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2014

|

Vol. 62, nr 1

129--137

EN

A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.

3

Doświadczalne wyznaczanie parametrów opisujących model interakcji ściany silosu i ośrodka sypkiego

Prusiel J. A.

Inżynieria i Budownictwo

|

2011

|

R. 67, nr 6

317-320

PL

Przedstawiono procedury wyznaczania modułu sprężystości Em ośrodka sypkiego składowanego w cylindrycznej komorze silosu na podstawie rezultatów własnych badań doświadczalnych. W trakcie badań mierzono przemieszczenia i odkształcenia modelu komory o wysokości 2,5 m i średnicy 0,8 m. Wyznaczony moduł sprężystości ośrodka sypkiego posłużył do określenia podatności dyskretnych więzów sprężystych modelujących współpracę między ścianką silosu i ośrodkiem sypkim w modelu obliczeniowym zastosowanym w testach numerycznych.

EN

Computational procedures for prediction of modulus of elasticity of bulk solid Em stored in cylindrical storage silo bin, proposed on the basis of the own experimental test results, were presented in the paper. The displacements and strains of silo chamber model with a height of 2.5 m and diameter of 0.8 m were measured during experimental investigation. Calculated elastic modulus of bulk solid was used for determination of flexibility of discrete elastic constrains, modelling the interaction between silo bin wall and stored bulk solid in computational analysis based on FEM model tests.