Abstract: Theoretical analysis and simulation research were carried out to explore TBM scraper force condition and working process. And a force model of the scraper and rock while they were interacting was established. A geotechnical damage constitutive model was established based on the DruckerPrager yield and failure criterion. The established FEM model was verified by the real tools of EPB Φ628m fullface TBM， which were used in Shenyang subway project. Influences of different working parameters in the cutting process， such as cutting depth and rake angles were discussed and summarized by simulating the scraper working process. The results were verified by the fact that the scraper forces conformed to the wear patterns， which provided significant research theory and experimental reference for the working mechanism of TBM scraper.

Key words: scraper, DruckerPrager criterion, finite element analysis, stress distribution, wear pattern