Project Card 05

Finite Element Simulation of Thoracic Compression and Injury Criteria

Project Pathway

🟦 Numerical / Computational Modeling (FEM)

1. Background & Motivation

Thoracic injuries are a leading cause of morbidity and mortality in automotive crashes, falls, and blunt impact accidents. The thorax exhibits a complex biomechanical response due to its composite structure, including ribs, sternum, spine, and internal organs. Injury mechanisms range from rib fractures to lung contusions and cardiovascular injuries.

In trauma biomechanics, thoracic injury risk is commonly assessed using global kinematic and deformation-based injury criteria, such as chest acceleration, chest compression, and the Viscous Criterion (VC). Finite element (FE) modeling provides a valuable tool for studying thoracic response under controlled loading conditions and for comparing the behavior of different injury criteria.

This project focuses on developing and using a simplified FE model of the thorax to investigate thoracic compression mechanisms and evaluate commonly used thoracic injury criteria.

2. Core Biomechanical Question

How do thoracic compression characteristics and loading conditions influence thoracic injury criteria predicted by a simplified finite element model?

3. Injury Mechanisms & Relevant Injury Criteria

The project should address the following biomechanical aspects:

Thoracic injury mechanisms:
- Chest wall compression
- Rib cage deformation
- Rate-dependent thoracic response
Frontal blunt loading scenarios

Relevant thoracic injury metrics may include:

Chest compression (deflection-based criteria)
Chest acceleration
Viscous Criterion (VC)
Combined thoracic indices (conceptual discussion)

Students must justify the selection of injury criteria and explain their biomechanical significance and limitations.

4. Modeling / Analysis Approach

This is a numerical FEM-based project using a simplified thoracic model.

The student is expected to:

Develop or adapt a simplified FE representation of the thorax
Model key structural components (rib cage, sternum, spine) at a conceptual level
Apply frontal compression or impact loading representative of thoracic trauma
Compute and interpret thoracic injury metrics

High anatomical fidelity is not required. The emphasis is on mechanisms, trends, and injury metric interpretation.

5. Technical Specification (Core Section)

The project must include a clear and structured description of:

a) Geometry and Model Structure

Simplified thoracic geometry
Representation of ribs and sternum
Justification of geometric simplifications

b) Material Modeling

Material assumptions for bony and soft tissues
Rate-dependence or damping (if considered)
Rationale for parameter selection

c) Boundary Conditions and Loading

Loading configuration (e.g., rigid impactor, distributed compression)
Loading rate or velocity
Constraints and contacts

d) Output Quantities

Chest deflection and compression
Chest acceleration
Computation of VC and other injury metrics
Post-processing workflow

6. Parametric / Sensitivity Study

A limited parametric study is required, such as:

Variation of loading rate or impact velocity
Variation of thoracic stiffness parameters
Comparison between different injury criteria responses

The goal is to identify relative trends and sensitivities, not absolute injury thresholds.

7. Validation Strategy & Limitations

The project must explicitly discuss:

Qualitative or quantitative comparison with published thoracic impact experiments
Sensitivity of injury metrics to modeling assumptions
Limitations related to:
- simplified thoracic anatomy,
- absence of internal organ modeling,
- lack of experimental validation

Students must clearly state which conclusions are supported by the model.

8. Feasibility & Computational Considerations

The project must address:

Software used (e.g., Abaqus/Explicit, LS-DYNA)
Computational cost and runtime
Mesh density and timestep considerations
Numerical stability and contact handling

Models requiring excessive computational resources are discouraged.

9. Expected Outcomes

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

A simplified FE thoracic compression model
Computed thoracic injury metrics for selected loading scenarios
Sensitivity analysis results
A critical interpretation of thoracic injury predictions

The outcome should demonstrate numerical competence and biomechanical insight.

10. Deliverables

Final Report (20-25 pages, excluding appendices)
Model description and representative 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 thoracic injury scenario	10%
Injury mechanism understanding	Correct interpretation of thoracic biomechanics	15%
Injury metric selection & justification	Appropriate and critical use of thoracic criteria	10%
FEM model formulation	Quality of geometry, materials, BCs, and assumptions	20%
Parametric / sensitivity analysis	Insightful exploration of trends and criteria comparison	15%
Validation & limitations	Realistic discussion of model credibility	15%
Technical clarity & professionalism	Quality of documentation and figures	15%
Total		100%

12. Project Scope Agreement

By choosing this project, the student agrees to:

Emphasize injury mechanism interpretation over model complexity
Clearly document assumptions and limitations
Avoid overinterpretation of simplified injury predictions

Note:
Thoracic injury criteria are context-dependent; understanding their assumptions is as important as computing their values.