Triaxial variation of the modulus of elasticity in the thermo-elastic range of six tropical wood species

This work highlights the effect of temperature on the modulus of elasticity following the orthotropic axis of six species of tropical woods: assamela, bibolo, doussie, iroko, movingui, and sapelli of scientific names Afzelia, Pericopsiselata, Distemonanthus benthamianus, Entandrophragma cylindricum, Miliciaexcelsa, and Lovoatrichilioides, respectively. The four-point bending and compression tests were conducted to determine the failure loads, which can help further tests performed in the elastic domain. In order to determine the Young's modulus in the thermoselastic field, the above tests were carried out at different levels of loads and temperature; the samples of 20 x 20 x 340 mm dimensions for bending tests and 20 x 20 x 60 mm dimensions for compression tests according to current standards. The strains were read by means of two strain gauges, connected to the strain gauge bridge. Test results under the different constant thermo-hydric conditions showed an increase in the longitudinal, radial and tangential MOE of all six species as the temperature increased from 22 degrees C to 40 degrees C, and a regression above 40 degrees C. In terms of lost in elastic modulus, due to the temperature, the tests showed the following classification: movingui < sapelli < iroko approximate to bibolo approximate to assamela < doussie. Those results may be crucial while selecting the wood species for a typical use in a range of temperature.