Alireza Farajzadeh Moshtaghin
École Polytechnique Fédérale de Lausanne
StatisticsLength scaleUltimate tensile strengthElasticity (economics)Statistical physicsStochastic modellingRandom fieldWork (thermodynamics)Logarithmic scaleExtreme value theoryTransverse planeComposite materialMarginal distributionWeibull distributionMaterials scienceMonte Carlo methodSnowQuasistatic loadingPicea abiesSpecimen lengthRadial directionStatistical variabilityTensile behaviorLength effectLength changeTransverse directionMaterial propertiesMathematicsMesoscale meteorologyElastic modulusAutocorrelationDisplacement (vector)Size effect on structural strengthUpper and lower boundsSpatial variability
6Publications
2H-index
15Citations
Publications 6
Newest
Abstract The aim of this work is the investigation of mesoscale/local variability in mechanical properties of clear timber in the radial direction. Clear Norway spruce wood, Picea abies, was used for cutting specimens of different lengths with a small cross-sectional area of 4 × 4 mm2, in the radial direction of timber boards, and tested under tensile loading. In some boards, specimens were positioned regularly and, in some others, randomly, and local deformations in each specimen were measured ...
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#1Alireza Farajzadeh Moshtaghin (EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 2
#2Steffen Franke (Bern University of Applied Sciences)H-Index: 7
Last. Anastasios P. Vassilopoulos (EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 28
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In this study, an experimental campaign was conducted to characterize the length effect on the elasticity and tensile strength of clear spruce wood parallel to the grain direction. Four groups of specimens of different lengths, cut from the same log, were tested under the same conditions under longitudinal tensile loading. The cross-sectional area of the specimens was selected as being constant and sufficiently small to exclude the effect of variations of the properties in the transverse directi...
10 CitationsSource
#1Alireza Farajzadeh Moshtaghin (EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 2
#2Steffen Franke (Bern University of Applied Sciences)H-Index: 7
Last. Anastasios P. Vassilopoulos (EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 28
view all 4 authors...
In the current study, a random field-based size effect model has been proposed for the longitudinal tensile strength of clear timber. Since the failure mode is brittle, the problem is basically an extreme value problem of finding the distribution of minima of strength fields for specimens of different volumes. The stochastic response has been evaluated based on the Monte Carlo method along with the weakest link theory. Within the framework of the spectral representation method, the Weibull distr...
2 CitationsSource
#2Steffen FrankeH-Index: 7
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In this work, clear timber specimens of different lengths with a small cross-sectional area were cut in the transverse direction of timber boards and tested under tensile loading. Regularly positioned and randomly positioned specimens were cut from different timber boards. Local deformations in each specimen were measured during the tests and the mechanical behavior of specimens of different lengths was compared. Statistics and size effects concerning the elastic modulus and strength were studie...
#2Steffen FrankeH-Index: 7
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Different factors such as age, location of timber within the tree, structural imperfections, load history such as wind and snow etc. can affect the material properties of timber. Consequently, there is a high variability in the mechanical properties which is sometimes referred to as ‘random spatial variability’. In this work, the spatial variability of the transverse elastic modulus of clear spruce wood is quantified by conducting mechanical tests. Specimens of 120 mm nominal length with a small...
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#2Steffen FrankeH-Index: 7
Last. Thomas Keller (EPFL: École Polytechnique Fédérale de Lausanne)H-Index: 45
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Different factors such as age, location of timber within the tree, structural imperfections, load history such as wind and snow etc. can affect the material properties of timber taken from the same species, and grown in the same geographical location and local growth conditions. Consequently, there is a high variability in the mechanical properties [1-2]. This variability is both spatial and random, and is sometimes referred to as ‘random spatial variability’ [3]. Four groups of specimens of dif...
1 Citations