Subject description
Wood is a natural, lignocellulosic material, in the technical sense an anisotropic polymer composite, with a wide range of uses. The variability and inhomogeneity of wood structure within and between tree species, which also depends on sociophysiological and other external natural factors, requires effective, rapid, and noninvasive measurement of relevant material properties. The need for monitoring wood properties ranges from standing trees in forest stands and trees in urban areas to processing, processing methods, and end products. Non-invasive techniques and methods based on the measurement of the vibromechanical response of the material provide an objective basis and enable rapid and effective monitoring of material properties and end products from wood and lignocellulosic composites.
The objective of this course is to familiarize students with the acoustic techniques and methods in sound, ultrasound, and infrasound available in the Department of Wood Science and Technology. Students will receive an overview of ultrasonic techniques, vibro-resonance techniques, and frequency response techniques. They will learn about acoustic tomography and its applications in forestry for quality assessment of standing trees and forest assortments, in arboriculture for detection of internal structural anomalies of trees, and in timber construction for investigation of load-bearing structural cross sections. Methods of modal analysis using vibro-resonance techniques will be explored for the study of elastomechanical properties of wood and wood-based composites, for the needs of wooden musical instrument manufacturing and building with wood. Ultrasonic analysis techniques for determining elastomechanical anisotropy and structural anomalies of solid wood and wood-based composites will be presented. Techniques for monitoring and analysing acoustic emissions will be also presented, which in conjunction with ultrasonic techniques are particularly important for monitoring and testing assemblies in timber constructions.
Acoustic measurement techniques will be presented by professional experts who regularly use these methods in their research work. The student will be able to select some relevant techniques and methods, master them theoretically and practically, and will be qualified to apply them to the chosen problem related to the topic of the proposed doctoral dissertation.
The subject is taught in programs
Objectives and competences
The aim of the course is to familiarize students with acoustic measurement techniques for the analysis of wood, lignocellulosic composites, and for the evaluation and monitoring of selected wood-based products. Students will be teached about both, the theoretical principles and the applications of acoustic measurement techniques throughout the entire forest-wood industry value chain. During the course the students will learn both the advantages and limitations of each method.
Competencies:
The individual methods will be tested on a real example. Students will be enabled to apply these methods independently in further research work.
Teaching and learning methods
Seminar (20 h)
Laboratory work (15 h)
Expected study results
Knowledge and Understanding:
Learn about the main acoustic measurement methods and techniques available for wood and lignocellulosic composites analysis and their application throughout the entire forest-wood industry value chain, from standing trees in the forest stand to processing of wood and lignocellulosic composites, and finally quality monitoring of end products.
Reflection:
Critically evaluate the suitability of individual acoustic measurement methods and techniques for testing research hypotheses and achieving research objectives.
Application:
Apply selected acoustic measurement procedures and methods to students’ own research question and test them on a practical example in a forest stand, a forest-wood value chain, a material or semi-finished product in processing or on the final product, respectively. The students will learn how to select appropriate methods when testing research hypotheses.
Basic sources and literature
Bucur, V. 2003. Nondestructive Characterization and Imaging of Wood. Springer. Berlin. 354 str.
Bucur, V. 2006. Acoustics of wood. Springer Series in Wood Science. Springer-Verlag, Berlin. 393 str.
Ross, R. 2015. Nondestructive Evaluation of wood. Forest Producty Laboratory, Madison, 169 str.
Študentom bo na razpolago gradivo s predavanj in vaj v elektronski obliki. Gradivo bo objavljeno pred začetkom predavanj na spletni strani. Za izdelavo seminarskih nalog in nadgradnjo razumevanja vsebin bodo študentje uporabili tudi svetovni splet.
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