Finite element simulation and experiment combined material cross wedge rolling damage critical value evaluation method

The invention relates to the field of material damage assessment methods, in particular to a material cross wedge rolling damage critical value assessment method combining finite element simulation and experiments. The method comprises the following steps: firstly, carrying out cross wedge rolling forming experiments of different rolling distances on a plate-type cross wedge rolling mill under a certain working condition by adopting a round bar-shaped blank; then, the obtained rolled pieces are subjected to X-ray nondestructive inspection, and the initial rolling distance and the initial rolling position where the materials are damaged and cracked in the cross wedge rolling deformation process are obtained; thirdly, finite element simulation is applied, a certain damage model is selected, and the cross wedge rolling forming process of the same geometric model under the same working condition is simulated; and finally, according to a damage calculation result of simulating the same rolling distance and part by