This paper presents a numerical and experimental investigation into the forces generated when cutting biomaterials with surgical scalpel blades. An elastomer with similar non-linear mechanical properties to human skin was chosen as a reference material for the investigation.

A pilot experiment was carried out in which a surgeon performed cutting trials on artificial skin. An average cutting velocity and absolute (resultant) cutting force were estimated and used to design an experimental test rig to measure forces generated when cutting the elastomer.

Finite element models were constructed in the non-linear finite element code ABAQUS. Very fine meshes were used to capture the near singular stress/strain state under the blade tip. The non-linear behaviour of the elastomeric substrate was implemented using a three-term Ogden strain energy density function. Viscoelastic parameters were determined by performing stress relaxation tests and implemented using a Prony series. The growth of the “cut” was achieved using multi-point constraint equations. The decision to whether the cut advanced (or not) was based on an isotropic damage function evaluated in the elements directly under the blade tip.

Force results from the cutting experiments and simulations for one blade profile were compared for the purpose of validating the model. While quantitatively similar some differences between the experimental and predicted forces have been observed. The possible reasons for these discrepancies are discussed. The finite element model has almost been used to assess the effect of the tool profile on the cutting force which is a measure of the suitability of the tool.