R-Code
The R-code software was written to
support the calculations for cracked body structural assessments
following the R5 and R6 Procedures. However failure assessment
diagram methods based on R5 and R6 methodology have been
widely adopted around the world including the American ASME,
Swedish, French, Chinese and Japanese national procedures
as well as the British BS 7910 standard. The R-Code software
can therefore be of great help with all the above.
The software can calculate the stress
intensity factor and collapse loads for a wide variety of
geometries, for high order through section stress variations.
Integrated crack opening, area and gas flow calculations
can be performed, for penetrating defects, to aid leak before
break analyses. Many other features are available to all
geometries including fatigue crack growth, treatment of
residual stresses, temperature dependent materials. Facilities
for calling Visual Basic© functions, subroutines
and external programs enable user specified features such
as collapse solutions. These powerful features give the
user access to internal information through ‘public
variables’ and provide an additional route for user
specified output.
The R-Code program includes:
- Stress Intensity Factor and Limit
Load solutions for over 100 geometry crack combinations
- Integrated crack and gas flow
calculations for ‘leak before break’ analysis
- Automatic sensitivity analysis
- QA tracking of all data
- Interactive result presentation
plus tabular postprocessor with interface to standard
spreadsheet formats
- Temperature dependent materials
- Visual Basic©
interpreter and use of external subroutines
- Option for user defined Stress
Intensity factors and collapse solutions
- Novice and Expert User modes
- User defined input and output
units and data checking
- Reference state methods for user
defined geometries
- Materials Database Facility
R-Code features for High Temperature
Use (R5)
In addition to the features already
mentioned, high temperature assessments will take account
of time dependent material properties and behaviour. The
program accessed in R5 mode
may be used to perform assessments taking account of creep
and fatigue crack growth. Several creep strain equations
are incorporated plus the Visual Basic©
route for users’ own equations. Allowance can be made
for crack incubation and any stress redistribution using
a number of different methods. Continuum damage may be evaluated
in terms of life fraction or ductility exhaustion methods
and checks can be made for crack stability under short term
loading. The results may be looked at in the post processor
and include not only the crack depth but also the creep
and fatigue contributions plus growth rates and parameters
such as C*, C(t), rupture time and normalised creep crack
growth rate, lambda.
R-Code features for Low Temperature
Use (R6)
R-Code
used in R6
mode has a number of features that do not apply to the R5
mode. Assessments can be undertaken for both of the R6 analysis
types, initiation and tearing. Material properties may also
vary with temperature or radiation dose where these may
vary through the section for non-fatigue calculations. For
fatigue calculations these may vary with time or position.
Sensitivity studies can be undertaken with a large choice
of sensitivity variables.
R-Code and finite element analyses
Finite element results can be used
directly by R-Code
for transferring the uncracked body stress distributions.
In R-Code
(R6 mode) stresses and strains may also be required from
an elastic-plastic analysis of the uncracked body; especially
if the secondary stresses are high when compared to the
primary ones. This facility uses a modification to the previous
theory that gives less conservative results. |
