Estimating Mechanical Properties of Wood in Existing Structures—Selected Aspects

Abstract

The paper presents and discusses selected methods of wood classification and the evaluation of its mechanical properties. Attention was mainly paid to methods that may be particularly useful for examining existing elements and structures. The possibility of estimating the modulus of rupture—MOR and modulus of elasticity—MOE based on the non- destructive (NDT), semi-destructive (SDT), and destructive tests (DT) were considered. Known international, European, and American standards and research approaches were indicated. The selected testing methods and their interpretation were presented. These were, among others, the method of visual assessment, the resistance drilling method, methods of determining the dynamic modulus of elasticity, and procedures for testing small clear specimens. Moreover, some of our own research results from the conducted experimental tests were presented and discussed. In the destructive tests, both large elements and small clear specimens were examined. The results obtained from individual methods were compared and some conclusions were presented. The summary discusses the fundamental difficulties and limitations in applying the presented procedures and interpretations.

On-Site Risk Assessment Methodology of Historic Timber Structures: The Case Study of Santa Cruz Church

“…In the case of the resistography test, the first publication applied to structural timber was very relevant [40], and it was applied later to the specific use of heritage timber buildings [41,42] and more recently applied to specific mechanical properties [43,44]. In addition, Ref.…”

“…However, as explained in [36,41], it should be noted that the resistography test is a specific test that analyses the dimension of the hole, so discontinuous information samples are obtained that can in no case be used to positively validate an element. On the contrary, when detecting negative alterations or imperfections, it determines the time to reject the pieces or weigh their intervention [43].…”

Loading rate effects on MOE and MOR distributions in testing of small clear beech wood specimens

“…Several recent studies have addressed the relationships between MOE and MOR of small clear specimens and structural size specimens (Butler et al 2016;Krajnc et al 2019;Nowak et al 2021). Cunha et al (2021), went a step further and examined the possibilities for characterizing mechanical properties only through small clear specimens.…”

Rotational Stiffness and Carrying Capacity of Timber Frame Corners with Dowel Type Connections

“…It is also possible to use specific dynamic testing [ 3 ] or the vibration acoustic method [ 4 ]. The diagnostics of existing structures and the determination of mechanical properties are closely related to the testing of mechanical properties [ 5 ]. The current possibilities of wood processing technology and design of structures allow a wide range of applications from simple structures, through multi-story buildings [ 6 ] to long-span structures [ 7 ].…”