Tearing behaviour of two types of leather: A comparative study carried out at the local scale using the full kinematic and thermal field measurement techniques

Abstract

Leather materials undergo various strain and stress states during their elaboration process and their application in numerous different functions. Among the key properties required for such materials, tearing resistance appears as one of the most important. In this paper, the tearing behaviour of two types of leather, a grain pigskin leather and a grain calf leather, was investigated at the local scale using the full‐field techniques. During the tests, thermal fields were measured at the surface of the two leathers by means of an infrared camera. Measurements of the displacement and deformation fields were also performed at the surface of the pigskin sample using the digital image correlation technique, which was not possible for the calf sample due to surface wrinkling. The results obtained enable us to discuss and compare the tearing resistance of both leathers in terms of the thermal activity in the zone of influence of the crack. The best tearing resistance was obtained for the grain calf leather that has undergone a retanning operation and whose matrix contained a plasticiser.

Thermomechanical characterization of leathers under tension using infrared thermography

“…This type of information could be used to propose accurate thermomechanical behavior laws for specific leathers. An analysis of the tearing response of leathers is also available in [46], in which investigations were carried out at the local scale using two full-field techniques (IR thermography and digital image correlation) in order to discuss the material's resistance in terms of thermal activity in the crack zone of influence. Finally, temperature measurements under stretching may be used for quality control at different steps of the manufacturing process, in order, for instance, to assess viscosity properties from the material's calorific response.…”

A thermodynamic framework for non-isothermal phenomenological models of isotropic Mullins effect

“…Interestingly, experimental techniques that go beyond the early days of experiments with filled rubber by [1,2] allow one to simultaneously measure-with a sufficient spatio-temporal resolution and accuracy-both strain and temperature fields in a material, see, e.g. [8][9][10][11][12][13]. For the early developments, see also [14][15][16].…”

A thermodynamic framework for non-isothermal phenomenological models of Mullins effect

“…Interestingly, experimental techniques that go beyond the early days of experiments with filled rubber by Mullins (1948Mullins ( , 1969, allow one to simultaneously measure-with a sufficient spatio-temporal resolution and accuracy-both strain and temperature fields in a material, see for example Toussaint et al (2012), Martinez et al (2013), Martinez et al (2015), Wang et al (2017), Di Cesare et al (2019 and Charlés and Le Cam (2020). For the early developments see also Chrysochoos and Louche (2000), Boulanger et al (2004) and Chrysochoos (2012).…”