engleski

Microtensile testing of wood – Overview of the practical aspects of methodology

Microtensile testing is a specific and delicate variant of standard tensile testing and is performed on small samples. Often also referred as “thin strip” method, the testing of thin veneers is described in this paper with particular aspects of its field and scope of application, along with comments on reliability and variability of results. Experimental guidelines of the precise technique are presented as well. The method consists of preparation of microtomed longitudinal wood sections which may be treated or exposed to various conditioins, agents or weathering, followed by tensile testing in a large number of replicas. Therefore the reduction in size of samples shortens and/or facilitates the testing. Testing at zero span (the jaws of testing instrument being initially in contact) reflects to a greater extent the mechanical properties of the cellulose component, while the finite (usually 10 mm) span test yields more information about matrix properties i.e. lignin intercellular material and the degree of fiber bonding. Shortcomings of the method exist insomuch that practical applicability is restricted to a small number of species, and that the great skill in material preparation, execution of testing and interpretation of results is required from an operator. The method may be time consuming and technically demanding, depending on species and type of experiment. However, further analyses on tested strips (like colour measurements, chemical analytical testing, biodeterioration studies etc.) render the method useful for a multi- aspect approach to specific studies on wood.

wood; thin strips; microtensile testing

nije evidentirano