SHEAR STRENGTH OF PINE WOOD BONDED JOINTS WITH DIFFERENT ANGLES OBTAINED USING COMPRESSION AND TORSIONAL TESTING METHODS

Padilha, Victor Hugo Lazzaretti; Petrauski, Alfredo; Santos, Alessandra dos; Possa, Desirè Coraça; Petrauski, Sandra Maria Ferreira Couri; Savaris, Gustavo

doi:10.1590/1806-908820230000027

Acessibilidade / Reportar erro

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Scientific Article • Rev. Árvore 47 • 2023 • https://doi.org/10.1590/1806-908820230000027 copy

SHEAR STRENGTH OF PINE WOOD BONDED JOINTS WITH DIFFERENT ANGLES OBTAINED USING COMPRESSION AND TORSIONAL TESTING METHODS

RESISTÊNCIA AO CISALHAMENTO À COMPRESSÃO E À TORÇÃO DE JUNTAS COLADAS DE PINUS E ADESIVO POLIURETANO CONFECCIONADAS COM DIFERENTES ÂNGULOS

Authorship SCIMAGO INSTITUTIONS RANKINGS

ABSTRACT

Glued Laminated Timber technology allows the construction of wooden structural components bonded with adhesive. This technology enables the creation of large-scale structures, with technological control over the material, and in a competitive industrial system. Focusing on the structural application of wood, the present study assessed the strength of bonded joints with different angles between the fibers of Pinus sp. wood, joined with a two-component polyurethane adhesive based on vegetable oils. The bonded joints were fabricated with angles of 0°, 10°, 20°, 30°, 45°, 60°, 70°, 80°, and 90°, and were evaluated for shear strength under compression and torsion. When regression analysis was performed, shear compression values showed compliance with Hankinson’s equation, with an R² value close to 0.76. However, shear torsion results yielded R² values near 0.17. Thus, Hankinson’s equation was unsuitable as an estimator for torsional shear strength values. The specimens showed a different mechanical response to shear when tested in compression compared to those tested in torsion.

Keywords:
Adhesion; Mechanical performance; Reforested wood

Table 1 Average shear strengths, including standard deviation, by test and bonding angles, and average shear strength and average density of test specimens by test and group.

Angles	Average shear strengths from shear tests (MPa)		Groups	Average strength and average density per group and shear test
Angles	Compression	Torsion	Groups	Compression		Torsion
0°	10.46± 1.58	7.13 ± 1.54		Mpa	g.cm^-3	Mpa	g.cm^-3
10°	10.22± 2.38	6.60 ± 2.10	G1	9.32	0.70	7.27	0.69
20°	9.87± 2.17	6.61 ± 1.24	G2	7.98	0.63	6.94	0.62
30°	8.44 ± 1.45	6.78 ± 1.65	G3	6.95	0.60	5.74	0.59
45°	6.40 ± 1.45	6.03 ± 1.68	G4	7.07	0.56	7.91	0.55
60°	5.10 ± 1.13	5.97 ± 1.52	G5	6.61	0.56	5.38	0.57
70°	4.39 ± 0.84	5.99 ± 1.33	G6	6.54	0.53	5.19	0.53
80°	4.22 ± 1.18	5.50 ± 0.82	G7	6.02	0.51	4.56	0.51
90°	3.90 ± 1.37	4.52 ± 1.20	G8	5.51	0.43	6.04	0.43

Table 2 ANOVA summary given the deployment of the test factor within angle.

Sources of Variation	df	Sum of squares	F-Test	p-value
Test / angle: 0°	1	44.57	34.67	<0.001
Test / angle: 10°	1	52.44	41.06	<0.001
Test / angle: 20°	1	42.49	33.27	<0.001
Test / angle: 30°	1	11.01	8.62	0.004
Test / angle: 45°	1	0.55	0.43	0.511
Test / angle: 60°	1	3.04	2.38	0.128
Test / angle: 70°	1	10.30	8.07	0.006
Test / angle: 80°	1	6.55	5.12	0.027
Test / angle: 90°	1	1.55	1.21	0.274
Error (subparcel)	63	80.46

Table 3 Estimated coeffi cients in the Hankinson model and their respective confi dence intervals and coeffi cient of determination.

Rehearsal	Parameters
Rehearsal	^fw^{^}0j	^fw^{^}90j	b^{^} j	Rj²
C	10.43 [9.63; 11.26]	3.97 [3.43; 4.53]	2.35 [2.00; 2.71]	0.756
T	6.79 [6.08; 7.56]	5.20 [4.59; 5.85]	2.19 [1.74; 2.64]	0.172

Sociedade de Investigações Florestais Universidade Federal de Viçosa, CEP: 36570-900 - Viçosa - Minas Gerais - Brazil, Tel: (55 31) 3612-3959 - Viçosa - MG - Brazil
E-mail: rarvore@sif.org.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] *Corresponding author.