PSI - Issue 37

Valérie Nsouami et al. / Procedia Structural Integrity 37 (2022) 576–581 Nsouami et al. 2021/ Structural Integrity Procedia 00 (2021) 000 – 000 Nsouami et al. 2021/ Structural Integrity Procedia 00 (2021) 000 – 000

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Moabi wood has a density of 0.87 ± 0.07. It is classified as hardwood having a pinkish brown to reddish brown color. This species is very much adored by the quality of its wood for interior and exterior carpentry (doors, windows, parquet floors, stairs, various fittings, works in contact with the ground or with fresh water) and wood in permanent contact with seawater (pillars, pontoons, submerged timber), heavy framework, for veneer (furnishings and decoration), for marine construction, for cabinetmaking, slicing and sculpture (CIRAD 2011; Doucet et Kouadio 2007). The objective of this study is to evaluate the mechanical parameters of the specimens subjected to long-term loading (9 years) to ensure the reliability of the structure. In other words, studying the mechanical behavior of tropical woods, in the case of Gabonese species in their immediate environment, is crucial to control their lifetime and guide locals in their choice of construction materials (Odounga et al. 2017). The different specimens were kept in an air-conditioned room and the tests were carried out in this same room where the average temperature and relative humidity were respectively 24.3 ° C and 43.8%. The mechanical parameters were adjusted to a moisture content of 12% for comparison. Moabi wood ha a density of 0.87 ± 0.07. I is class fied as hardwood having a pi kish brown to r ddish brown color. This species is very much adored by the quality of its wood for interior and exte ior carp ntry (do rs, windows, parquet floors, stairs, various fittings, works in contact with the ground or with fresh water) and wood in permanent contact with seawater (pillar , pontoons, su m rged timber), heavy framework, for veneer (furnishings an decoration), f r mar n construction, for cabine making, slicing and sculpture (CIRAD 2011; Douce et Kouadio 2007). The objective of this study is to evaluate the mechanical parameters of the specimens subjected to long-te m load ng (9 years) o ensure the reliability of the structure. In o h r words, studying the me hanical b havior of tropical woods, in the case of Gabonese species i their immediate e vironment, is crucial to control the r lifetime and guide locals in heir ch ice of cons ruction materials (Odounga et al. 2017). Th different speci ens were kept in an air-conditioned oom and the tests were carried out in this same room wh e the average temperature and relative humidity were respectively 24.3 ° C and 43.8%. The mechanical parameters were adjusted to a moisture content of 12% for comparison.

Nomenclature Nomenclature

Force increment Force increm nt Increase in the arrow Increase in the arrow Thickness of the specimen Thickness of th specimen Maximum force Maximum force Failure stress Failure stress Length of the specimen Length of the specimen Length of the specimen

 F  w F  w

b b

Fmax

FS FS h

max

l h l

MOAC4B MOAC4B MOS4B MOU4B S U4B MOAC4H MOS4H MOU4H S U4H MOAC4M MOS4M MOU4M S MOU4M AC4H AC4M

Specimen 4 of Moabi in lower part in an air-conditioned environment Specimen 4 of Moabi in lower part in a sheltered environment Specimen 4 of Moabi in lower part in a sheltered environment Specimen 4 of Moabi in upper part in an air-conditioned environment Specimen 4 of Moabi in upper part in a sheltered environment Specimen 4 of Moabi in upper part in a sheltered environment Specimen 4 of Moabi in middel part in an air-conditioned environment Specimen 4 of Moabi in middel part in a sheltered environment Specimen 4 of Moabi in middel part in a sheltered environment Specimen 4 of Moabi in lower part in an air-conditioned environment low sheltered environment n air-con itioned environment upper part in a sheltered environment n air-con itioned environment Specimen 4 of Moabi in middel part in a sheltered environment

2. Materials and Methods 2.1. Materials 2. Materials and Methods 2.1. Materials

The Moabi ( Baillonella toxisperma ) specimens are debited from three beams (89 × 176 × 3090 mm 3 ) storage in three tropical environments (air-conditioned, unsheltered exterior and sheltered exterior), see figure 1. These beams had been loaded during 9 years (Manfoumbi, 2012). In addition, these beams were sawn into nine sections 340 mm long. Fig. 2.b and 2.c show the different specimens obtained in height (upper part, middle part and lower), see Fig. 2a. From each section, we shoot two bending specimens (81 samples of section 15 × 15 mm 2 and 300 mm long), two for traction and four for the compression tests (78 specimens of section 20 × 20 mm 2 for 120 mm long). Please note that only bending tests have been presented and discussed in this paper. Please note that the density is obtained by the classical weighing method. Th M abi ( Baillonella toxisperma ) specimens ar d bited from three beams (89 × 176 × 3090 mm 3 ) storag in three tropical environme ts (air-conditioned, unsheltered exter or and sh lt red ext rior), see figure 1. These beams had been loaded during 9 years (Manfoumbi, 2012). In additio , these beams we e sawn into nine sections 340 mm long. Fig. 2.b and 2.c show the different specimens obtained in height (upper part, middle part and lower), see Fig. 2a. F om each secti n, we s oot two bending pecimens (81 samples of section 15 × 15 mm 2 and 300 mm long), two for traction a four for t e compression tests (78 specim ns of section 20 × 20 mm 2 for 120 mm long). Ple se note t at only bending tests have been presented and discussed in this paper. Please note that the density is obtained by the classical weighing method.

Fig. 1. a) Air-conditioned environment. b) Unsheltered environment. c) Sheltered environment Fig. 1. a) Air-conditioned environment. b) Unsheltered environment. c) Sheltered environment