Linear Elastic Fracture Mechanics (LEFM)

Lambda uses linear elastic fracture mechanics (LEFM) to predict fatigue crack growth behaviors of structures with damage and loading geometries. LEFM is used to understand crack growth behavior under the complex load history and residual stress distributions for LPB® and shot peening.

How does it work?

LEFM is based on the analysis of crack growth in linear elastic materials. It provides a tool for determining the life expectancy of structures and components. Based on linear elasticity theory, the stress intensity factor and the stress field near the crack tip can be calculated for a specific component. By comparing the total stress (calculated applied and measured residual) to the fracture toughness of the material, the onset of crack propagation can be determined. Our lab uses this in combination with the residual stresses measurement to determine the effect of residual stress on fatigue theoretically.

LEFM Features:

• Combines finite element applied stresses with measured residual stresses for life prediction
• Allows for quick understanding and comparison of beneficial compressive residual stress fields
• LEFM predictions are validated with component fatigue testing