Nonwovens are complex three-dimensional anisotropic structures and consisting of fibres orientated in certain directions, which are bonded by thermal, chemical, mechanical entanglement or a combination of these techniques. Thermally bonded are further classified in two categories, i.e. through-air and calendared nonwoven structures. In this study, a modified micromechanical model describing the tensile behaviour of thermally bonded nonwovens is proposed by incorporating the effect of fibre re-orientation during the deformation. The anisotropic behaviour of through-air bonded structures is demonstrated through theoretical stress-strain curves and the relationship between the fibre re-orientation and fabric strain is also analysed. Furthermore, the failure criterion of thermally bonded nonwovens is analysed using pull-out behaviour of fibres in the system. A parametric study revealing the dependencies of various structural and geometrical characteristics of fibres on pull-out behaviour of fibres in thermally bonded nonwovens is also discussed.