Strain Energy Release Rate

Strain energy release rate, abbreviarted as G, is used in fracture mechanics to quantify the energy required to propagate a crack in a material.  When a material contains a crack or a flaw, applying stress to the material may cause the crack to propagate, leading to failure.  In simpler terms, when a material with a crack is subjected to stress, the crack tends to propagate.  The strain energy release rate measures how much energy is needed to extend the crack per unit area.  It's a parameter used in understanding and predicting the propagation of cracks in materials under various loading conditions.

Understanding the strain energy release rate is used in fracture mechanics for assessing the propensity of materials to fracture and for designing structures to withstand such fractures.  It helps engineers and scientists evaluate the toughness and durability of materials under various loading conditions.

 

Strain Energy Release Rate formula
\( G_1 \;=\; K_1^2 \;/\; E \)     (Strain Energy Release Rate) \( K_1 \;=\; \pm  \sqrt{ G \; E  }  \) \( E \;=\; K^2 \;/\; G  \)
Symbol	English	Metric
\( G_1 \) = strain energy release rate	\(lbf-ft\;/\;ft^2\)	\(J\;/\;m^2\)
\( K_1 \) = stress intensity factor in Mode I	\( dimensionless \)
\( E \) = Young's modulus	\(lbf\;/\;in^2\)	\( Pa \)

 

Strain Energy Release Rate formula
\( G_1 \;=\; (1 - v^2) \; K_1^2  \;/\; E \)
Symbol	English	Metric
\( G_1 \) = strain energy release rate	\(lbf-ft\;/\;ft^2\)	\(J\;/\;m^2\)
\( V \) = Poisson's ratio	\( dimensionless \)
\( K_1 \) = stress intensity factor in Mode I	\( dimensionless \)
\( E \) = Young's modulus	\(lbf\;/\;in^2\)	\( Pa \)