Characterisation of human diaphragm at high strain rate loading

Area of Science:

• Biomechanics
• Trauma research
• Material science

Background:

• Motor vehicle crashes (MVCs) frequently cause severe thoracic and abdominal injuries.
• Accurate material models and tissue tolerance limits are essential for finite element analysis of automotive-related soft tissue injuries.
• Diaphragm rupture is a serious injury resulting from blunt trauma, necessitating an understanding of its high-rate failure properties.

Purpose of the Study:

• To determine the mechanical and failure properties of human diaphragm tissue.
• To investigate these properties at strain rates relevant to blunt thoracic and abdominal trauma.

Main Methods:

• Conducted 23 uniaxial tensile tests on human diaphragm tissue specimens.
• Tested specimens to failure at four distinct strain rates: 0.001s⁻¹, 65s⁻¹, 130s⁻¹, and 190s⁻¹.
• Utilized high-speed video to measure displacement and calculated engineering stress and strain.

Main Results:

• Human diaphragm tissue exhibits strain rate dependency.
• Higher strain rates resulted in significantly higher failure stress and failure strains.
• Failure stress ranged from 1.17 MPa to 4.1 MPa, and failure strain ranged from 12.15% to 24.62%.

Conclusions:

• The mechanical response and failure characteristics of the diaphragm are influenced by the rate of applied strain.
• These findings provide critical data for improving injury prediction models in automotive safety research.
• Understanding diaphragm tissue's rate-dependent behavior is vital for mitigating traumatic rupture in MVCs.