184,390 research outputs found
Elasticity measurement using holographic interferometry double exposure technique
Holographic measurement of modulus elasticity was performed on samples of aluminum can. It is based upon the measurement of the displacement as a function number of fringes appeared on the body of the loaded can. The value of the modulus elasticity for the aluminum can is obtained as (1.00 ± 0.03) × 108 nm–2. This result is found in good agreement with a mechanical measurement by taking into account any experimental erro
Evaluation of the mechanical properties of self compacting concrete using current estimating models. Estimating the modulus of elasticity, tensile strength, and modulus of rupture of self compacting concrete
This study includes an analysis of the applicability of current models used for estimating the mechanical properties of conventional concrete to self-compacting concrete. The mechanical properties evaluated are: modulus of elasticity, tensile strength, and modulus of rupture. An extensive database which included the dosifications and the mechanical properties of 627 mixtures from 138 different references, was used. The models considered are: ACI, EC-2, NZS 3101:2006 (New Zealand code) and the CSA A23.3-04 (Canadian code). The precision in estimating the modulus of elasticity and tensile strength is acceptable for all models; however, all models are less precise in estimating the modulus of rupture
An investigation on the stiffness of timber sleepers for the design of fibre composite sleepers
This paper presents an experimental investigation on timber railway sleepers with a view to select a suitable stiffness and a modulus of elasticity for the design of a fibre composite railway sleeper. Eight full size timber sleepers were tested using a four point bending test arrangement. An overview of existing material for railway sleepers is also presented. Based on the tests, it is concluded that timber sleepers have significant variation in strength and stiffness as can be inferred from the modulus of elasticity (Esleeper) which ranged between approximately 9520 MPa and 27600 MPa. It is desirable to develop a concept fibre composite sleeper within a similar range of modulus of elasticity. Based on the statistical analysis, it is proposed to use the lower tail value that is 12000 MPa as design modulus of elasticity for the fibre composite railway sleeper
Tungsten fiber-reinforced copper composites form high strength electrical conductors
Tungsten fiber-reinforced copper composites have tensile strength, yield strength, and modulus of elasticity proportional to fiber content. The composites form high strength electrical conductors
Readily fiberizable glasses having a high modulus of elasticity
New glass compositions yield composites having higher moduli of elasticity and specific moduli of elasticity than commercially available glasses. Over a reasonable temperature range the glasses have a viscosity of about 20,000 poises. They consist of silica, alumina, magnesia, and beryllia, plus at least one uncommon oxide
Analysis of a typical railway turnout sleeper system using grillage beam analogy
A simplified grillage beam analogy was performed to investigate the behaviour of railway turnout sleeper system with a low value of elastic modulus on different support moduli. This study aimed at determining an optimum modulus of elasticity for an emerging technology for railway turnout application - fibre composites sleeper. The finite element simulation suggests that the changes in modulus of elasticity of sleeper, Esleeper and the sleeper support modulus, Us have a significant influence on the behaviour of turnout sleepers. The increase in Us from 10 to 40 MPa resulted in a 15% reduction in the bending moment while the increase in Esleeper from 1 GPa to 10 GPa has resulted in almost 75% increase in the bending moment. The shear forces in turnout sleepers is not sensitive to both the changes of the Esleeper and Us while the sleeper with low Esleeper tend to undergo greater settlement into the ballast. An Esleeper of 4 GPa was found optimal for an alternative fibre composite turnout sleeper provided that the Us is at least 20 MPa from the consideration of sleeper ballast pressure and maximum vertical deflection. It was established that the turnout sleeper has a maximum bending moment of 19 kN-m and a shear force of 158 kN under service conditions
- …
