A combined experimental and numerical study of stab-penetration forces

TL;DR

This study combines experimental stabbing tests and finite element modeling to quantify the force involved in knife penetration of biological tissue, aiming to improve forensic analysis of stabbing incidents.

Contribution

It introduces a novel integrated experimental and numerical approach to measure stab forces, enhancing forensic tools for force estimation in stabbing cases.

Findings

Quantified stab forces at various speeds and blade types.

Developed a finite element model capable of simulating stabbing events.

Provided data for potential predictive models of stabbing force.

Abstract

The magnitude of force used in a stabbing incident can be difficult to quantify, although the estimate given by forensic pathologists is often seen as `critical' evidence in medico-legal situations. The main objective of this study is to develop a quantitative measure of the force associated with a knife stabbing biological tissue, using a combined experimental and numerical technique. A series of stab-penetration tests were performed to quantify the force required for a blade to penetrate skin at various speeds and using different `sharp' instruments. A computational model of blade penetration was developed using ABAQUS/EXPLICIT, a non-linear finite element analysis (FEA) commercial package. This model, which incorporated element deletion along with a suitable failure criterion, is capable of systematically quantifying the effect of the many variables affecting a stab event. This quantitative data could, in time, lead to the development of a predictive model that could help indicate the level of force used in a particular stabbing incident.