The deformation characteristics of thin-walled parts during shot peening are simulated by the coupled finite and discrete element methods (FEM–DEM). A shot peening strengthening model with multiple random shots based on Almen strip is established and verified by shot peening test. The flat

straight and thin-walled specimen in the model warps upward in arc shape after random shot peening. The deformation characteristics are consistent with the actual shot peening deformation of Almen strip. When the shot peening pressure increases from 0.07 MPa to 0.11 MPa

the simulated arc height increases from 0.340 mm t

o 0.521 mm

and the simulation accuracy of arc height can reach 95%; The residual stress field introduced by random shot peening on the surface of Almen strip shows an S-shaped barb distribution along the depth direction. With the increase of shot peening pressure

the simulated surface residual compressive stress increases from about –400 MPa to about –700 MPa

and the maximum error comparing with the test results is 11.31%; The surface roughness R

a

of Almen strip rises with the increase of shot peening pressure

and the simulated roughness value increases from 0.476 μm to 0.630 μm

and the maximum error of simulation is 6.78%. Through comparison and verification

the simulation results of the model are in good agreement with the shot peening test results. FEM–DEM coupled random shot peening model can better simulate the variation law of deformation

residual stress field and roughness of thin-walled parts.