Various laser shock processing methods are provided to establish selective
compressive residual stress distribution profiles within a workpiece. An
asymmetrical stress distribution profile may be formed through the
thickness of a thin section of a gas turbine engine airfoil. One method
involves simultaneously irradiating a workpiece with a set of laser beams
to form a corresponding set of adjacent non-overlapping laser shock peened
surfaces, enabling the shockwaves to encounter one another. Additionally,
opposite sides of the workpiece may be irradiated at different times to
form opposing laser shock peened surfaces, enabling the shockwaves to meet
at a location apart from the mid-plane. Furthermore, opposite sides of the
workpiece may be irradiated simultaneously using laser beams having
different pulse lengths to form opposing laser shock peened surfaces.
Moreover, opposite sides of the workpiece may be irradiated simultaneously
to form a set of laterally offset laser shock peened surfaces.
