The anisotropic mechanical behaviour of electro-spun biodegradable polymer scaffolds: Experimental characterisation and constitutive formulation

During scaffold degradation, maximum stress and strain in circumferential direction decreased from 1.02±0.23 MPa to 0.38±0.004 MPa and from 46±11% to 12±2%, respectively. In longitudinal direction, maximum stress and strain decreased from 0.071±0.016 MPa to 0.010±0.007 MPa and from 69±24% to 8±2%, respectively. The constitutive parameters were identified for both directions of the non-degraded and degraded scaffold for strain range varying between 0% and 16% with coefficients of determination r2>0.871. The six-parameter constitutive formulation proved versatile enough to capture the varying non-linear transversely isotropic behaviour of the fibrous scaffold throughout various stages of degradation.