Effect of Moisture Content in Rubberwood with Heat Treatment on the Performance of Glued-laminated Timber Beams under Sustained and Cyclic Loads

2022 ◽  
Vol 34 (4) ◽  
Author(s):  
Thippakorn Udtaranakron ◽  
Warawit Eakintumas ◽  
Tawich Pulngern
Keyword(s):  
Heat Treatment ◽  
Moisture Content ◽  
Cyclic Loads ◽  
Glued Laminated Timber ◽  
Effect Of Moisture ◽  
Timber Beams

Study on the strength of glued laminated timber beams with round holes: difference in structural performance between homogeneous-grade and heterogeneous-grade timber

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Shigefumi Okamoto ◽  
Nobuhiko Akiyama ◽  
Yasuhiro Araki ◽  
Kenji Aoki ◽  
Masahiro Inayama
Keyword(s):  
Scots Pine ◽  
Maximum Shear Stress ◽  
Material Strength ◽  
Laminated Beams ◽  
Strength Grade ◽  
Glued Laminated Timber ◽  
The Difference ◽  
Materials Used ◽  
Beam Height ◽  
Timber Beams

AbstractVarious design codes and design proposals have been proposed for glued laminated timber beams with round holes, assuming that the entire beam is composed of homogeneous-grade timber. However, in Japan, glued laminated timber composed of homogeneous-grade timber is rarely used for beams. In this study, the difference in the load-bearing capacity of glued laminated beams composed of homogeneous-grade timber and heterogeneous-grade timber with round holes when fractured by cracking was investigated experimentally and analytically. The materials used in the tests were glued laminated beams composed of homogeneous-grade Scots pine timber with a strength grade of E105-F345 and heterogeneous-grade Scots pine timber with a strength grade of E105-F300. Experiments confirmed that although the glued laminated beams composed of heterogeneous-grade timber have a lower material strength in the lamina with holes, its resistance to fracturing due to cracks associated with the holes is almost the same as that of the glued laminated beams composed of homogeneous-grade timber. The stresses acting on the holes in the laminated timber with holes of less than half the beam height were lower in the glued laminated beams composed of heterogeneous-grade timber than in the glued laminated beams composed of homogeneous-grade timber. The ratio of the stresses was found to be approximately equal to the ratio of the maximum bending stress or the maximum shear stress acting on the inner layer lamina, as determined by Bernoulli–Euler theory.

scholarly journals Effect of Moisture Content on the Processing and Mechanical Properties of a Biodegradable Polyester

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1616
Author(s):  
Vincenzo Titone ◽  
Antonio Correnti ◽  
Francesco Paolo La Mantia
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Moisture Content ◽  
Mechanical Testing ◽  
Hydrolytic Degradation ◽  
Slight Reduction ◽  
Biodegradable Polyester ◽  
Molding Process ◽  
Elongation At Break ◽  
Effect Of Moisture

This work is focused on the influence of moisture content on the processing and mechanical properties of a biodegradable polyester used for applications in injection molding. The pellets of the biodegradable polyester were exposed under different relative humidity conditions at a constant temperature before being compression molded. The compression-molded specimens were again placed under the above conditions before the mechanical testing. With all these samples, it is possible to determine the effect of moisture content on the processing and mechanical properties separately, as well as the combined effect of moisture content on the mechanical properties. The results obtained showed that the amount of absorbed water—both before processing and before mechanical testing—causes an increase in elongation at break and a slight reduction of the elastic modulus and tensile strength. These changes have been associated with possible hydrolytic degradation during the compression molding process and, in particular, with the plasticizing action of the moisture absorbed by the specimens.

A thermal modification technique combining bulk densification and heat treatment for poplar wood with low moisture content

2021 ◽  
Vol 291 ◽  
pp. 123395
Author(s):  
Xianju Wang ◽  
Dengyun Tu ◽  
Chuanfu Chen ◽  
Qiaofang Zhou ◽  
Huixian Huang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Moisture Content ◽  
Thermal Modification ◽  
Poplar Wood ◽  
Modification Technique

Structural Changes on Charring Woods of Dichrostachys and Salix from Southern Africa: The Effect of Moisture Content

IAWA Journal ◽  
1986 ◽  
Vol 7 (3) ◽  
pp. 243-250 ◽  
Author(s):  
Juliet Prior ◽  
K. L. Alvin
Keyword(s):  
Moisture Content ◽  
Southern Africa ◽  
Structural Changes ◽  
Initial Increase ◽  
Dichrostachys Cinerea ◽  
Chemical Changes ◽  
Structural Alterations ◽  
Wood Pyrolysis ◽  
Effect Of Moisture ◽  
Physical And Chemical

Air-dried and saturated cubes of fully developed wood of Dichrostachys cinerea (Leguminosae) and Salix subserrata (Salicaceae) were charred for 60 minutes at 400°C. An initial increase in moisture content caused few structural alterations in Salix but in Dichrostachys it resulted in considerable ray distension and massive deformation of non-gelatinous fibres. An attempt is made to correlate these observations with the physical and chemical changes known to occur during wood pyrolysis.

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