Bending test for capturing the vivid behavior of giant reeds, returned through a proper fractional visco-elastic model

• Relationship between visco-elastic properties and moisture content is investigated.
• Stress relaxation tests in three point bending configuration are performed.
• The fractional model labeled spring-pot is the most suitable and simplest.
• Only two parameters labeled α and Cα properly characterize the fractional model.
• The Euler–Bernoulli beam embedded with the spring pot model is really appropriate.

This paper presents results of experimental investigations made to evaluate the vivid behavior of giant reed Arundo donax. In particular, attention was paid to the relationship between visco-elastic properties and moisture content, which is widely recognized as one of the key factor that influences the mechanical properties of all wood-based materials. To this aim, after a controlled drying treatment on samples of reed, stress relaxation tests in three point bending configuration were performed to evaluate the effects of moisture content on visco-elastic behavior of the giant reed. Further, the novel aspect of this paper is that of using an Euler–Bernoulli model embedded with an advanced visco-elastic constitutive law to fit experimental data of bending tests. Such a model of continuum beam takes into account different constitutive laws of viscoelasticity, being natural materials visco-elastic.