Timber poles for overhead lines. Test methods. Determination of modulus of elasticity, bending strength, density and moisture content

AbstractThe possibility for pre-grading of logs throughout the year has been evaluated based on dynamic modulus of elasticity (MOEdynor simplifiedEdyn) by means of frequency-based nondestructive testing (NDTfreq). The challenge is thatEdynis variable in the frozen, partly frozen, and unfrozen states of logs (state of matter). In the unfrozen state, NDTfreqis reliable if the moisture content does not fall below fiber saturation. The state of the matter was tested via temperature measurements of air and log by means of an infrared technique and sensors, and information was evaluated from NDTfreq. The temperature measurements proved to be inefficient for industrial application because of unreliable data and long measurement times, whereas the NDTfreqmeasurements allowed the determination of meaningful damping factors. A sufficient level of predictability for more than 60% of the measurements was found. The log measurements in the partly frozen state are inconclusive becauseEdyndata fluctuate in the presence of both liquid and frozen water. For the completely frozen logs, a correction is introduced as a precaution that avoids an overestimation ofEdynin the unfrozen state.

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Determination of elastic parameters of grain with oedometric and acoustic methods

Research in Agricultural Engineering ◽

10.17221/4953-rae ◽

2012 ◽

Vol 49 (No. 2) ◽

pp. 56-60 ◽

Cited By ~ 4

Author(s):

M. Stasiak

Keyword(s):

Hydrostatic Pressure ◽

Moisture Content ◽

Shear Wave ◽

Equilibrium Moisture Content ◽

Shear Wave Velocity ◽

Modulus Of Elasticity ◽

Uniaxial Compression Test ◽

Elastic Parameters ◽

Acoustic Methods

Values of modulus of elasticity E and Poisson’s ratio   were determined with two methods adopted from geotechnique. First approach used was a method proposed by Sawicki (1994). This type of examination was applied to estimate values of E and v for wheat and rapeseed beddings for five levels of moisture content ranging from 6% to 20%. Modulus of elasticity E of wheat was found to decrease with an increase in moisture content. With the second method values of E were determined based on measurement of shear wave velocity. Tests were performed for bedding of wheat and rapeseed under equilibrium moisture content. Values of modulus of elasticity were found to depend of hydrostatic pressure and were higher then those determined in uniaxial compression test.

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Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass

10.1520/d2216-05 ◽

2005 ◽

Cited By ~ 4

Author(s):

Keyword(s):

Moisture Content ◽

Test Methods ◽

Laboratory Determination

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The effect of mat layers moisture content on some properties of particleboard

Drvna industrija ◽

10.5552/drvind.2019.1821 ◽

2019 ◽

Vol 70 (3) ◽

pp. 221-228

Author(s):

Abdullah Istek ◽

Ismail Ozlusoylu

Keyword(s):

Mechanical Properties ◽

Moisture Content ◽

Modulus Of Elasticity ◽

Bending Strength ◽

Physical And Mechanical Properties ◽

Core Layer ◽

Formaldehyde Resin ◽

Internal Bonding ◽

The Core ◽

Internal Bonding Strength

In this study, the effect of mat moisture content on the physical and mechanical properties of particleboard was investigated. The experimental boards were produced by using 40 % softwood, 45 % hardwood chips, and 15 % sawdust. The formaldehyde resin/adhesive was used in three-layers (bottom-top layer 12 %, core layer 8 %). Multi-opening press was used during manufacturing the experimental particleboards. The physical and mechanical properties of boards obtained were identified according to the TS-EN standards. The optimum core layer moisture content was determined as 6 % and 7 % according to the results, whereas the moisture content of bottom and top layers was 14 %. Under these moisture content conditions, the bending strength was found to be 13.3 N/mm², the modulus of elasticity in bending 2466 N/mm², and internal bonding strength 0.44 N/mm². The optimum bottom-top layer moisture content was determined to be between 13 % and 15 % and 6.5 % for the core layer.

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