DYNAMICAL BEHAVIOR OF HARDWOOD SPECIES SUBJECTED TO CYCLIC BENDING STRESSES

Autor/autori: Mariana Domnica STANCIU, Ioan CURTU, Adriana SAVIN


Abstract: Hardwood species as beech, maple, cherry, alder are used in common application such furniture, musical instruments, ornaments in automotive construction, panels and floors. The stresses vary in time as intensity, duration and type. From this point of view, some mechanical properties decrease conducting to strength and stability loss. In this paper, it was analyzed dynamical behavior of four hardwood species in laboratory conditions using Dynamical Mechanical Analyzer. The samples were subjected to cyclic bending in isothermal conditions (30oC), with intensity force by 6 N with a frequency of 1 Hz applied on radial and tangential direction of wood structure. It was determined variation of storage and loss modulus (E’ and E”) and damping (tan δ). The second investigation based on temperature variation in range between 30oC and 90oC, it was analyzed the glass transition of wood, knowing that it is a natural lignocellulose composite.

Keywords: wood, dynamical mechanical analyzer, complex modulus, glass transition, damping

 

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