TWI Industrial Member Report Summary 769/2003
C M Wignall
Normally when assessing the integrity of structures using fracture mechanics standard procedures such as BS 7910:1999 or R6 are used. These procedures are conservative, sometimes excessively so, because the toughness is usually measured using a specimen such as a single edge bend specimen that has a high degree of constraint at the crack tip. In many structural components the level of constraint can be much lower and this gives the structure higher fracture toughness than the equivalent fracture mechanics specimen.
- To establish a more realistic, yet conservative, approach to constraint based assessment procedures.
- To quantify the sensitivity of constraint to flaw dimensions, location and orientation.
- To quantify the sensitivity of constraint to changes in material properties.
- To determine whether the results of the analysis agree with data from the open literature.