Determinação da densidade básica da madeiras de Eucalyptus por diferentes métodos não destrutivos

Gouvêa, Adriana de Fátima Gomes; Trugilho, Paulo Fernando; Gomide, José Lívio; Silva, José Reinaldo Moreira da; Andrade, Carlos Rogério; Alves, Isabel Cristina Nogueira

doi:10.1590/s0100-67622011000200019

Cited by 24 publications

(19 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Regarding the fact that Dummy variables were not found for the LRS prediction based on the BD, it is supposed that the equipment used to measure this parameter (durometer Pylodin) presents low precision, which probably harmed the correlation between LRS and BD. Such result is confirmed in previous studies, as McKenzie et al (2003) and Gouvêa et al (2011), who found low correlations between the BD and the strength to drill obtained by Pylodin.…”

Section: Discussionsupporting

confidence: 89%

USE OF DUMMY VARIABLES TO PREDICT GROWTH STRESSES IN Eucalyptus ssp. CLONES

et al. 2016

View full text Add to dashboard Cite

-The evaluation of growth stresses in Eucalyptus trees and their influence on both morphological properties of trees and technological properties of wood have been aimed by several studies, which used indirect and nondestructive methods for these evaluations. The present study aimed to estimate growth stresses for woods from Eucalyptus ssp. clones trough some of their dendrometric properties, using Dummy variables. 12 hybrid Eucalyptus clones were evaluated by basic density (BD) and dendrometric properties: diameter at breast height (DBH), bark thickness (BT), height (H) and total volume (VOL). The growth stresses were indirectly evaluated by the longitudinal residual strain (LRS) following the CIRAD-Forêt method. 12 Dummy variables were defined based on the characteristics of each clone. After that, four models were proposed in order to estimate the LRD, using Dummy variables, DBH, H, VOL and BD as independent variables. Among the dendrometric properties, BD was discarded because it does not confer interesting aids to the LRD predict. Among the Dummy variables, clone 9 provided the most discrepant variable. The LRD of the clones were satisfactorily described by the mathematical models, although these values showed significant variability.Keywords: Technological parameters; CIRAD-Forêt method; Mathematical models. USO DE VARIÁVEIS DUMMY PARA A PREDIÇÃO DE TENSÕES DE CRESCIMENTO EM CLONES DE Eucalyptus spp.RESUMO -O presente estudo objetivou estimar as tensões de crescimento da madeira de clones de Eucalyptus spp., por meio de algumas de suas propriedades dendrométricas, utilizando-se de variáveis Dummy. Foram selecionados 12 clones híbridos do gênero Eucalyptus, dos quais foram avaliadas as propriedades dendrométricas: diâmetro a altura do peito (DAP), espessura de casca (EC), altura (H), volume total (VOL); bem como a densidade básica (DB). As tensões de crescimento foram avaliadas de maneira indireta, por meio da deformação residual longitudinal (DRL), medida conforme o método CIRAD-Forêt. Foram definidas 12 variáveis Dummy com base nas características de cada clone. Após, a fim de estimar matematicamente a DRL, foram propostos quatro modelos utilizando-se como variáveis independentes: DAP, H, VOL, DB e as variáveis Dummy. Dentre as propriedades dendrométricas, a DB foi a única descartada por não aportar subsídios interessantes para a predição da DRL. Na comparação entre as variáveis Dummy, o clone 9 deu origem à variável mais discrepante em relação às demais. Contudo, os resultados obtidos indicaram que, embora tenha havido uma variabilidade significativa nos níveis de DRL na comparação entre os diferentes clones, os modelos matemáticos obtidos descreveram satisfatoriamente as tensões de crescimento dos mesmos.Palavras-chave: Parâmetros tecnológicos; Método CIRAD-Forêt; Modelos matemáticos.

show abstract

Section: Discussionsupporting

confidence: 89%

USE OF DUMMY VARIABLES TO PREDICT GROWTH STRESSES IN Eucalyptus ssp. CLONES

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Pin penetration should be negatively correlated with basic density, for the higher the density of the material the greater its resistance to pin penetration and, consequently, the shallower the depth reached by the Pilodyn ® pin (GOUVÊA et al, 2011a(GOUVÊA et al, , 2011bNEVES et al, 2011;THIERSCH et al, 2006;VALE et al, 1995;WU et al, 2010).…”

Section: Couto a M Et Almentioning

confidence: 99%

Modeling of basic density of wood from Eucalyptus grandis and Eucalyptus urophylla using nondestructive methods

Couto¹,

Trugilho

Neves³

et al. 2013

CERNE

Self Cite

View full text Add to dashboard Cite

ABSTRACT:The objective of this study was to evaluate the accuracy of nondestructive variables in inferring basic density of wood from Eucalyptus grandis and Eucalyptus urophylla. A total of 27 clones of Eucalyptus urophylla and 22 clones of Eucalyptus grandis were used, sourced from a clonal trial set up in Martinho Campos, Minas Gerais. After evaluation using nondestructive techniques of resistography and pin penetration at a constant pressure (Pilodyn ® ), individuals were felled and disks were removed from the 2%, 10%, 30%, 50% and 70% portions of the merchantable height section, and also from the portion 1.30 m above ground level. Basic density was determined by the water immersion method. Values of basic density ranged from 0.412 to 0.609 g.cm -3 for clones at age 42 months and from 0.408 to 0.664 g.cm -3 for clones at age 54 months. The clones of Eucalyptus urophylla provided higher values of average basic density in relation to Eucalyptus grandis. The variable 'amplitude' had better correlation with basic density in comparison with pin penetration at a constant pressure. Nondestructive evaluation can be used in mass preselection of genetic materials, prior to subjecting them to a more accurate, reliable evaluation.

show abstract

“…For., Piracicaba, v. 44, n. 111, p. 683-690, set. 2016 DOI: dx.doi.org/10.18671/scifor.v44n111.14 no uso final (ROSS; PELLERIN, 1994;GOUVÊA et al, 2011;TRIANOSKI, 2012;MIRBOLOUK;ROO-HNIA, 2015), além de promoverem economia de tempo e recursos finaceiros na obtenção dos dados, quando comparados aos ensaios destrutivos (SHOKRIEH;MOHAMMADI, 2014).…”

Section: Introductionunclassified

Determinações dos módulos de elasticidade e ruptura de madeiras por técnicas não destrutivas e destrutiva

Neto¹,

Paes²,

Segundinho³

2016

Sci. For.

View full text Add to dashboard Cite

ResumoEste trabalho objetivou avaliar o uso de técnicas não destrutivas (dinâmicas) por meio de frequências de vibração (longitudinal e transversal) e stress wave e relacionar os resultados com os obtidos no ensaio destrutivo (estático) na determinação da rigidez e resistência da madeira de quatro espécies florestais. Foram utilizadas tábuas com 200 x 40,0 x 5,0 cm (comprimento x largura x espessura) das madeiras de eucalipto (Corymbia citriodora), louro preto (Cordia alliodora), massaranduba (Manilkara sp.) e pau brasil (Caesalpinia echinata) e avaliados o módulo de ruptura (MOR) por técnica destrutiva (estática) e o módulo de elasticidade (MOE) por meio de técnicas destrutivas e não destrutivas ou dinâmicas (vibração longitudinal, transversal e stress wave). Para a análise e avaliação dos resultados, empregou-se um delineamento inteiramente casualizado, com quatro tratamentos (espécies) e 20 repetições por tratamento e os valores, quando significativos pelo teste F (p ≤ 0,05), tiveram suas médias comparadas pelo teste de Tukey (p ≤ 0,05). A avaliação das relações entre as técnicas estática e dinâmicas foi por meio do teste de Pearson. O eucalipto apresentou os maiores valores de módulos de elasticidade e ruptura. A técnica de vibração transversal proporcionou os maiores coeficientes de correlações entre as técnicas testadas. As melhores correlações entre os MOEs foram obtidas para as madeiras de menores massas específicas e para o MOR não foi observado nenhuma relação entre as massas específicas. Palavras-chave: técnicas de vibração, flexão estática, correlação linear. AbstractThis work aimed to evaluate the use of non-destructive techniques (dynamic) by means of vibration frequencies (longitudinal and transversal) and stress wave and to relate the results with those obtained in destructive test (static) in determining the stiffness and strength of the four woody forest species. Planks with 200 x 40.0 x 5.0 cm (length x width x thickness) of Corymbia citriodora, Cordia alliodora, Manilkara sp. and Caesalpinia echinata were evaluated and the modulus of rupture (MOR) by destructive technique (static) and modulus of elasticity (MOE) by means of destructive and non-destructive techniques or dynamics (vibration transversal and longitudinal stress wave). For the analysis and evaluation of the results, a completely randomized design with four treatments (species) and 20 repetitions per treatment was used and the values, when significant F test (p ≤ 0.05), had their averages compared by Tukey's test (p ≤ 0.05). The evaluation of the relationship between static and dynamic techniques was through the Pearson's test. Eucalypts presented the highest values of elasticity and rupture modules. The transverse vibration technique provided the greatest correlation coefficients among the tested techniques. The best correlations among the MOEs were obtained by woods of lower specific gravities for the MOR was and no relationship among the specific gravities was observed. Keywords INTRODUÇÃOA qualidade da madeira pode ser avaliad...

show abstract

Determinação da densidade básica da madeiras de Eucalyptus por diferentes métodos não destrutivos

Cited by 24 publications

References 6 publications

USE OF DUMMY VARIABLES TO PREDICT GROWTH STRESSES IN Eucalyptus ssp. CLONES

USE OF DUMMY VARIABLES TO PREDICT GROWTH STRESSES IN Eucalyptus ssp. CLONES

Modeling of basic density of wood from Eucalyptus grandis and Eucalyptus urophylla using nondestructive methods

Determinações dos módulos de elasticidade e ruptura de madeiras por técnicas não destrutivas e destrutiva

Contact Info

Product

Resources

About