The strength of a rib can be defined by several material properties, including Young's modulus, yield strength, and ultimate tensile strength. Specifically for human ribs, these properties have been measured and reported.
Rib Strength Properties
Based on research, human rib strength is characterized by the following:
- Young's Modulus: Measures stiffness. The Young's modulus of human ribs ranges from 10 to 17 GPa.
- Yield Strength: Measures the stress a material can withstand before permanent deformation occurs. Human ribs have a yield strength between 60 and 100 MPa.
- Ultimate Tensile Strength: Represents the maximum stress a material can withstand before it starts to break. For human ribs, the ultimate tensile strength is 80 to 120 MPa [14, 16].
Understanding the Properties
To understand these values better, consider the following:
- A higher Young's modulus indicates a stiffer material, meaning it requires more force to deform.
- A higher yield strength means the rib can withstand greater stress before permanently changing shape.
- A higher ultimate tensile strength implies the rib can endure more stress before fracturing.
Example
Imagine pulling on a rib. The ultimate tensile strength (80-120 MPa) is a measure of how much pulling force (tensile stress) the rib can handle before it breaks. The yield strength (60-100 MPa) indicates at what point the rib will start to bend or deform permanently under that pulling force. The Young's modulus (10-17 GPa) tells you how much the rib will stretch under a given amount of pulling force before it reaches its yield strength.
