Advanced science.  Applied technology.

Search

DARWIN Capabilities

 

DARWIN® supports users throughout the design process:

Input

DARWIN provides a graphical user interface (GUI) to facilitate the development of analyses for the underlying computational engine. Through the GUI, users can completely specify the deterministic and random variables needed to launch an analysis.

  • Geometries
    • 1-D stress profiles (no FE model provided)
    • 2-D axisymmetric FE models
    • 3-D FE models
  • Anomaly Size Distributions
    • Ellipsoidal inclusions/voids
    • Surface damage
    • Corrosion pitting
    • Anomalies introduced during maintenance at shop visits
    • Multiple anomalies
  • Inspections
    • NDE probability of detection (POD) curves
    • Variable inspection times
    • Multiple inspections with linked times
  • Mission Mixing
    • Build missions from multiple load steps
    • Define mission blocks composed of multiple missions
    • User defined mission sets
    • Randomly generated sets of missions
    • Global units of hours, flight cycles, and TACs
  • Input from Materials Processing Simulations
    • Deterministic and random residual stresses
    • Deterministic and random anomaly orientation
    • Deterministic and random average grain size

 

Methods

DARWIN features advanced computational methods to determine fracture lives of components subjected to cyclic stress history.

  • Automation
    • Zone definitions with one element per zone
    • Zone definitions using an optimal zone break-up
    • Zone definitions using an optimal zone break-up based on pre-zones
    • Fracture model definition
  • Crack Geometries
    • Elliptical embedded cracks
    • Semi-elliptical surface cracks
    • Quarter-elliptical corner cracks
    • Straight through cracks
    • Automatic crack transitioning
    • K tables for arbitrary cracks
  • Probabilistic Methods
    • Monte Carlo
    • Life approximation functions
    • Gaussian processes
    • Importance sampling
  • Optional Random Variables
    • Initial anomaly size (up to 6 variables)
    • Stress scatter
    • Life (material property) scatter (2 variables)
    • Inspection schedules
    • NDE Probability of detection
  • Anomaly Types
    • Inherent
    • In-service (shop visit)
    • Manufacturing (initial)
    • Stress induced
  • Crack Growth Models
    • Six da/dN equations
    • Three mean stress models
    • Tabular da/dN vs.DK data
    • Five stress-temperature models
    • da/dN + da/dt superposition models
  • Computational Engine Options
    • Parallel processing
    • Interactive and batch modes
    • Windows, Linux, and Mac
  • Life Assessment Options
    • Univariant or bivariant weight functions
    • Crack formation
    • Crack propagation
    • Time-dependent crack growth
    • Overload crack growth retardation
    • Fracture toughness multiplier
    • Vacuum properties for embedded cracks
    • High-cycle fatigue threshold
  • Risk Assessment Options
    • Manufacturing inspections
    • In-service inspections at random times
    • Component replacement
    • Fleet risk

Results

DARWIN summarizes data in the GUI from the computational engine that determine service lives and fracture risk values.

  • Contour Visualization
    • Stress
    • Temperature
    • Life
    • Fracture risk
    • Critical initial crack size
    • Residual stresses
    • Grain size
    • Response surfaces
  • Risk Summary Graphs
    • Fracture risk vs. load cycle
    • Fracture risk per cycle vs. load cycle
    • Local contribution to risk vs. load cycle
    • Relative contribution to risk of local regions
  • Fracture Mechanics Visualization for Individual Cracks
    • Crack dimensions vs. load cycle
    • Crack area vs. load cycle
    • SIF vs. load cycle
    • Crack growth per load cycle 
  • Stress Processing
    • View stress contours with crack location
    • Sort stresses by mission, location, and stress direction
    • Elastic, relaxed (elastic-plastic shakedown), and residual stresses
    • Normalized and real coordinates systems
    • Univariant and bivariant stress plots
    • Stress concentration effects

Interfaces

DARWIN connects with software packages that are commonly used and trusted for engineering systems. Click here for a list of software interfaces available with DARWIN.

  • Finite element data formats
    • ANSYS
    • Abaqus
    • SIESTA
    • HSIESTA
  • Third party software
    • DEFORM (Scientific Forming Technologies Corporation)
    • FRANC3D (Fracture Analysis Consultants)