Abstract:For clarifying the effect of intermittent multi-body contact state on kiln shell stress and mechanical strength,different shell thicknesses were selected as sample points by the design of experiment method,and the shell stresses and fatigue life were obtained corresponding with the sample points by finite element analysis,then kriging surrogate model was constructed.Taking the fatigue life of support segments,transition segments,and end and middle segments as the optimal goal,and considering shell thicknesses,cross section deformations,and flexibilities as constraints,the improved multi-objective genetic algorithm (MOGA Ⅱ) was applied to conduct a comprehensive search for the optimal results of surrogate model in a given design space,and the optimal shell thicknesses were obtained.The results showed that the minimum fatigue life enhances from 48.4 years to 89.3 years,and the shell lives tend to be equal,even,and the same at support segments,transitional segments,and middle segments,respectively.