Papers by Author: Shui Cheng Yang

Abstract: The flaws such as crack or slag inclusion, in the welded seam of header of a 300MW steam turbine generator unit, were detected by the ultrasonic non-destructive inspection. Based on the crack modeling, the finite element method (FEM) was used to calculate and analyze the displacement field, stress field and stress intensity factors of the cracks under the conditions of warm start, cold start and normal operation, and the residual service life was predicted. Analyzing results showed that these flaws would not bring about primary brittle fracture and propagation of crack was harmless to safe in operation.

Abstract: The authors present a procedure for the analysis of the stability and propagation of cracks in arch dams based on linear elastic fracture mechanics. A finite element method was used to calculate the stress intensity factors(KⅠ, KⅡ and KⅢ) of crack in the concrete arch dam, and fracture analysis for arch dams was carried out, which based on the criterion of three-dimensional mixed mode fracture of concrete from the experiment. The analysis method can be applied to evaluate the safety of the arch dam and improve the design for arch dam.