The aim of this paper is to determine the effect hole diameter (LR Direction) on acoustic performance indicators such as coefficient and conversion efficiency wooden beams using flexural vibration a free-free bar test.The drilling from 0 8 millimetres was made exactly at middle bar, node second mode vibration. results revealed that holes millimeters didn’t cause any sever change when beam impacted both radial tangential surfaces. Nevertheless, these properties changed bit surface. Thus,...

It is preferred to perform conformity assessment of wood-based panels on the whole panel without cutting it down smaller pieces. The modulus elasticity, a mechanical property wood, was determined by longitudinal vibration testing with full-size panel, and results were compared tests prismatic beams. Brancheriau’s correction coefficient used compensate for errors from cross-sectional dimension variations Poisson’s ratio. Longitudinal excitation along length shown be successful in evaluating...

Abstract In this study, researchers attempted to investigate the effects of drilling and hole widening on dynamic response wood using nondestructive methods. Clear sound rectangular (2 × 2 36 cm R T L) bars were prepared from Beech timber (Fagus orientalis) drilled in four steps with 3, 5, 8 10-mm diameters at central points length tangential (LT) surface radial (LR) direction. To evaluate longitudinal modulus elasticity, free–free before after procedure brought free flexural vibration test....

An inexpensive methodology is proposed to identify and locate a single defect within wooden beam using free flexural vibration technique. A similar approach has been introduced in the literature based on longitudinal vibration, which was selected be leading frontier for present research. The technique tested five groups of absolutely clear specimens while holding manually drilled hole at 0.1, 0.2, 0.3, 0.4, 0.5 their total span. beams were with both ends condition before after drilling,...

The damping coefficient of the first mode in longitudinal vibration mulberry and walnut woods was characterized to find justifications for water soaking traditional musical instrument industries Iran. Visually clear sound beams were prepared from Morus alba Juglans regia, temporal field evaluated before after three continuous cycles specimens distilled (24 hours, pH 7, temperature 50 oC). Experiments conducted with free using free-free bar method 360 × 20 (L ×R ×T) dimensions. Soaking...

There are different dynamic or static test methodologies for evaluating the shear and torsional moduli of wood. A preferred method is nondestructive, accurate, standard. However, methods using conventional devices previously suggested determining orthotropic wood neither accurate nor Thus, a reliable modulus through vibration exists; however, it not standard at all. In this study, methodology refractory materials, ASTM C1548, was fitted to meet qualifications in measuring an material. based...

It was previously reported that extractives from Pernambuco wood (a species Leguminosae family, native to South America) are positive for acoustical performance of wood.Thus the present study set investigate effect extraction in hot water and ethanol/acetone mixture on properties Persian silk (Albizia julibrissin, a Iran).Contactless forced flexural vibration both freeends beams performed thin small specimens before after extraction.Results showed extractive components soluble were...

In this study, the elastic properties of 23 specimens oak timber (Quercus castaneifolia), including longitudinal modulus elasticity (MOE), acoustic coefficient (K), and converting efficiency (ACE) in free vibration using free-free beam method with different planes vibration, i.e. tangential (LT) radial (LR), were studied.These parameters examined both sound wood finger jointed timbers two lengths fingers (5-and 10-mm lengths) individually glued types adhesives (isocyanate polyvinyl...

Due to considerable influence of shear deflection and rotary motion, the modulus elasticity is hardly obtainable in fixed-free flexurally-excited (cantilever) beams.For isotropic materials, Timoshenko has proposed a set curves correct modal frequencies as radius gyration free length; however, its performance for wood was not sufficiently conclusive.In this study, rectangular beams pine were tested condition, altering length height ratios proper extent comparing them their reference free-free...

The capability of application fl exural vibration test in nondestructive evaluation wood drying was studied.Poplar timbers were conventionally kiln dried under three different schedules down to the fi nal moisture content 12 ±2 %.Dynamic Modulus Elasticity, damping (internal friction), acoustic coeffi cient, and converting effi ciency each sample evaluated using free both-ends bars before after drying, while dynamic responses individual step also monitored.Results revealed that emerging some...

Background: The impact of three different coating formulations, used traditionally in Iranian musical instrument industry, on acoustical properties wooden soundboard was investigated. Methods: Shellac, Opaque Polyester Varnish (OPV) and Sandrous powder solution (50 5% solutions Ethanol), were applied pine wood then the samples tested using forced vibration technique. measured parameters specific modulus elasticity, acoustic coefficient converting efficiency. Results: results indicated that,...

Despite the progress in synthetic polymer industries, wood is one of main materials making musical instruments because its unique characteristics. Many instrument makers try to improve acoustic properties by traditional treatments. In this study, changes walnut during processes fermentation pretreatment, water washing, and organic solvent washings were evaluated. For this, samples divided into two groups 20. first group, de-extraction was started with while second group directly underwent...

The competitiveness of the laminated flooring industry was assessed in Iran. statistical population 200 persons, calculated using stratified random method and Cochran formula. sample size 132. After reviewing literature, a conceptual model derived from theoretical framework presented. A researcher-made questionnaire used to collect data. Content validity confirmatory factor analysis were determine questionnaire. Its reliability confirmed Cronbach’s alpha coefficient. results processed...

In the present paper changes of validity in Euler-Bernoulli's elementary theory flexural vibration for homogeneous materials were tested with respect to changing severity and position a single defect wood.As an orthotropic material, wood has different material properties or strengths orthogonal directions.A set absolutely clear specimens oriental beech was chosen hand drilled diameters (severities) at relative distances from end oriented R direction.A specimen showed steady decrease...

The elastic properties of oak wood (solid wood, scarf-jointed beams, and finger-jointed beams) two different, independently applied adhesives (polyvinyl acetate isocyanate) were investigated. Using a longitudinal vibration technique comparing the modulus solid jointed it was revealed that longer fingers (10 mm) in finger joints larger angle (70° 75°) beams enhanced beams. Based on these findings, concluded configurations result are most similar to those wood. application polyvinyl rather...

Dynamic supply and demand equations for particleboard using a three-stage squares simulation (3SLS) were estimated. Empirical data included annual observations over the period of 1976 to 2006. The stationary character was checked by applying Augmented Dickey-Fuller (ADF) Test. results revealed that in function, variables such as price, gross national product (GNP) previous year (lagged quantity), MDF price significant at 0.05%. In medium density fiberboard (MDF), year, product/raw material...

Consumer preferences were examined with respect to the decision-making process purchase home and office furniture in Iran. A conceptual model was proposed based on theoretical framework from literature. The data obtained interviews customers who buying wooden furniture. main collection tool this study a questionnaire. results processed using structural equation modelling (SEM) SmartPLS software. SEM is multivariate method that combines multiple regression factor analysis aspects. PLS-SEM has...