Project Card 03

Simplified Finite Element Model of Head Impact for Injury Assessment

Project Pathway

🟦 Numerical / Computational Modeling (FEM)

1. Background & Motivation

Finite element (FE) modeling has become a central tool in trauma biomechanics for investigating head injury mechanisms that cannot be directly measured experimentally, such as internal stress and strain distributions in the skull and brain. Simplified FE head models are widely used for educational purposes, sensitivity studies, and early-stage injury analysis.

This project focuses on developing and using a simplified FE model of head impact to investigate head injury mechanisms and extract commonly used injury metrics. Emphasis is placed on modeling assumptions, injury metric interpretation, and sensitivity to impact conditions, rather than on geometric or material complexity.

2. Core Biomechanical Question

How do impact conditions and modeling assumptions influence biomechanical injury metrics predicted by a simplified finite element head model?

3. Injury Mechanisms & Relevant Injury Criteria

The project should consider:

Head injury mechanisms associated with impact:
- Translational acceleration
- Rotational motion
- Stress/strain development in cranial structures (conceptual level)
Role of impact direction and velocity

Relevant injury metrics may include:

Resultant head acceleration
Head Injury Criterion (HIC)
Peak rotational acceleration
Simplified strain-based indicators

Students must justify the choice of injury metrics and discuss their physical meaning and limitations.

4. Modeling / Analysis Approach

This is a numerical modeling project using a simplified FE framework.

The student is expected to:

Develop or adapt a simplified FE head model (e.g., skull-brain system)
Define appropriate material models (linear elastic, viscoelastic, or simplified alternatives)
Apply impact loading scenarios representative of head trauma
Extract and interpret injury-related outputs

High anatomical fidelity is not required. Model clarity and biomechanical reasoning are prioritized.

5. Technical Specification (Core Section)

The project must include a clear and detailed description of:

a) Geometry and Mesh

Head model geometry (simplified representation)
Mesh type and resolution
Justification of simplifications

b) Material Models

Material assumptions for skull and brain
Rate-dependence (if considered)
Rationale for chosen parameters

c) Boundary Conditions and Loading

Impact configuration (e.g., rigid surface, helmeted/unhelmeted)
Impact velocity or acceleration
Constraints and contacts

d) Output Quantities

Extracted kinematic signals
Injury metrics computation
Post-processing workflow

6. Parametric / Sensitivity Study

A limited parametric study is required, such as:

Variation of impact velocity
Variation of material stiffness or damping
Variation of boundary conditions

The goal is to assess trends, not precise injury thresholds.

7. Validation Strategy & Limitations

The project must explicitly discuss:

Qualitative or quantitative comparison with literature data
Sensitivity to modeling assumptions
Limitations due to:
- simplified geometry,
- material modeling,
- lack of experimental validation

Students must clearly state what conclusions are justified and what are not.

8. Feasibility & Computational Considerations

The project must address:

Software used (e.g., Abaqus/Explicit, LS-DYNA)
Computational cost and runtime
Mesh and timestep considerations
Reproducibility of simulations

Models requiring excessive computational resources are discouraged.

9. Expected Outcomes

By the end of the project, the student should deliver:

A working simplified FE head impact model
Injury metric results for selected scenarios
Sensitivity analysis results
A critical interpretation of injury predictions

The outcome should demonstrate numerical competence and biomechanical insight.

10. Deliverables

Final Report (20-25 pages, excluding appendices)
Model description and key figures
Injury metric plots and tables
Oral presentation (15-20 minutes)

Optional appendices:

Input files
Post-processing scripts
Additional simulation cases

11. Project-Specific Grading Rubric

Criterion	Description	Weight
Problem formulation & relevance	Clear definition of injury scenario and objectives	10%
Injury mechanism understanding	Correct biomechanical interpretation of head impact	15%
Injury metric selection & justification	Appropriate and critical use of injury criteria	10%
FEM model formulation	Quality of geometry, materials, BCs, and assumptions	20%
Parametric / sensitivity analysis	Meaningful exploration and interpretation of trends	15%
Validation & limitations	Honest discussion of model credibility and limits	15%
Technical clarity & professionalism	Quality of documentation, figures, and explanations	15%
Total		100%

12. Project Scope Agreement

By choosing this project, the student agrees to:

Prioritize interpretation over complexity
Clearly document assumptions and limitations
Avoid unjustified injury claims based on simplified models

Note:
A simplified FE model, when correctly interpreted, can provide deeper insight than a complex but poorly validated one.