Nondestructive Techniques for Determination of Wood Mechanical Properties of Urban Trees in Madrid

Abstract

The aim of this paper is to analyze the mechanical properties of Robinia pseudoacacia L. (black locust), Platanus × hybrida Brot. (London plane), Ulmus pumila L. (Siberian elm), and Populus alba L. (white poplar), estimated using ultrasound wave equipment (USLab y Sylvatest Duo) and impact wave equipment (Microsecond Timer) on standing trees, felled logs and on specimens obtained from different parts of the trees. Bending strength, axial compression strength and tension parallel to grain were determined for each specimen, in order to subsequently correlate the strength and stiffness with the acoustic properties determined in the standing tree. For the relationship between the static modulus of elasticity of the specimens and the dynamic modulus of elasticity determined in standing trees using the USLab, coefficients of determination were found to be between 0.30–0.92, between 0.52 and 0.80 using the Sylvatest Duo and between 0.60 and 0.94 with the Microsecond Timer. It would be necessary to determine whether the removal of bark for the correct coupling of the ultrasonic sensors would provide an entry route for pests or diseases that could affect the health of the tree.

Based on the finite element method to analyse pull-out strength of round tenon joints in solid wood furniture

“…Round tenon is widely used in structures of traditional wood furniture and modern panel furniture due to its advantages of wood savings and its simple structure [4][5][6][7] . However, basic properties of wood, which is a natural polymeric biomaterial, inevitably deteriorate with age due to natural and human intervention; as a result, the mechanical properties of the mortise and tenon joints deteriorate, ultimately affecting the safety of the overall structure [8][9][10][11][12] . Structural strength of furniture products is the basis for realizing product functions; therefore, it is crucial to investigate the mechanical properties of mortise and tenon joints for the safety of solid wood furniture [13][14][15][16][17] .…”