Durability prediction and fatigue analysis
Virtual Strain Gauge and Virtual Sensor
Enables correlation between test and finite element results. Gauges (single or rosette) or displacement sensors may be graphically positioned and oriented on finite models as a post-processing step. Time histories due to applied loads can be extracted for direct correlation with your measured strain or displacement data.
Crack Growth
Provides a complete fracture mechanics capability using industry standard methodologies for specified locations on an FE model. Built-in growth laws include NASGRO, Forman, Paris, Walker and more. Select from a pre-populated library of geometries or supply custom stress intensity factors.
Signal Processing
nCode Fundamentals is included for basic data manipulation, analysis and visualization. Duty cycles can be defined by selecting from and building multiple cases. This feature makes it easy to create a composite duty cycle with repeats.
Materials Manager
Enables materials data to be added, edited and plotted. A standard database with fatigue properties for many commonly used materials is included.
Custom Analysis
Enables Python or MATLAB scripts to be used to extend existing analysis capabilities - perfect for proprietary methods or research projects.
FE-Display
Enables the graphical display of FE models with contours of stress results. Animating displacements from FE results or animation files display structural deformation under load.
Vibration Manager
Enables vibration specification data to be entered, edited, and viewed. A standard database containing over 100 vibration entries is included.
Processing Threads
Enables you to get finished results from raw inputs in faster. DesignLife can parallel process on machines with multiple processors, each Processing Thread license allowing another core to be utilized.
Strain-Life (EN) for low-cycle fatigue
The Strain-Life method is applicable to a wide range of problems including low-cycle fatigue with the local elastic-plastic strain controls the fatigue life. The standard EN method uses the Coffin-Manson-Basquin formula, defining the relationship between strain amplitude εª and the number of cycles to failure Nf. Material models can also be defined using general look-up curves. This enables the ability to interpolate multiple material data curves for factors such as mean stress or temperature.
- Material models:
- Standard EN
- EN mean multi-curve
- EN R-ratio multi-curve
- EN temperature multi-curve
- Gray Iron
- Strain combination methods or critical plane analysis
- Stress-strain tracking for accurate cycle positioning
- Back calculation to target life
- Multiaxial Damage models:
- Wang Brown
- Wang Brown with Mean
- Brown-Miller
- Brown-Miller with Mean
- Mean stress corrections:
- Walker
- Morrow
- Smith Watson Topper
- Interpolate multiple curves
- Plasticity corrections:
- Neuber
- Hoffman-Seeger
- Seeger-Heuler
- Multiaxial assessment:
- Biaxial
- 3D Multiaxial
- Auto-correction
DesignLife simplifies the process of setting up fatigue analysis of seam welds by intelligently identifying weld lines in an FE model. The Seam Weld option enables the fatigue analysis of seam welded joints including fillet, overlap, and laser welded joints. The method is based on the approach developed by Volvo (see also SAE paper 982311) and validated through years of use on vehicle chassis and body development projects.
- Uses stresses either from FE models (shell or solid elements) or stresses from grid point forces or displacements at the weld
- General material data for seam welds for both bending and tension conditions are supplied
- Appropriate for weld toe, root and throat failures
- Thick welds can be assessed using the stress integration method outlined in ASME Boiler & Pressure Vessel Code VIII (Division 2) standard
- Automated method to identify the weld locations from the solid FE model
- Corrections available for sheet thickness and mean stress effects.
- Structural stress at the weld toe, the hot-spot stress can be estimated by the extrapolation of the surface stress at points near the weld
- Supports BS7608 welding standard, together with required material curves
Frequency based fatigue analysis
The Vibration Fatigue option provides the capability to predict fatigue in the frequency domain and it is more realistic and efficient than time-domain analysis for applications with random loading such as wind and wave loads or where structures are excited by rotating machinery.
- Simulates vibration shaker tests driven by random PSD, swept-sine, sine-dwell, or sine-on-random loading.
- FE models are solved for frequency response or modal analysis. Vibration loading is defined in DesignLife and can include effect of multiple temperature and static offset load cases.
- Complete duty cycles can combine different vibration loading types and then with time-domain loads for more complex loadings.
- Multiple simultaneous frequency domain PSD loads can be applied including cross spectra to simulate real-world loading.
- Frequency domain inputs can be quickly and directly generated from time series data.
- Vibration fatigue can be used for stress-life, strain-life, seam weld, spot weld and short fibre composite analysis methods providing the most extensive frequency domain fatigue simulation capabilities commercially available.
Calculate loads from measured strains
The Strain Gauge Positioning option calculates the optimum position and number of gauges required to enable the subsequent reconstruction of applied load histories.
The Loads Reconstruction glyph uses the virtual strains created by unit loads along with the measured strain histories from gauges matching the virtual strain gauges to reconstruct the force histories that caused the measured strains.
Visualize, analyze, filter and report
nCode Fundamentals includes support for a wide range of data formats and types of displays. It is a pre-requisite for all other product options and provides visualization and basic manipulation, frequency spectrum analysis, filtering capabilities, and automated reporting.
- Electric Power glyph
- Input/output support of multiple data formats
- Channel calculator
- Channel reassignment
- Filtering
- Extraction and concatenation
- Statistics and running statistics
- Resampling
- Unit conversion
- Frequency analysis
- Time at level analysis
- Rainflow counting
- Graphical editor
- Visualization and reporting
- Batch and interactive interface
- SuperGlyph to encapsulate multiple analysis functions as a single glyph that can be saved and reused
- ScheduleCreate durability duty cycle definition
Vibration test profile design
Vibration Profile Design (formerly Accelerated Testing) provides the ability to create a representative PSD or swept sine shaker vibration test based on measured data. It uses the fatigue damage spectrum approach as described in NATO STANAG 4370 (AECTP-240)/ UK DefStan 00-35/Mil-Std-810G, allowing users to tailor vibration tests to a target vibration environment. With Vibration Profile Design, users can also compare existing test evidence against the requirements of a known test specification, enabling assessment of whether components in service will likely survive to the target service life. This known safety margin may help extend the life of parts in service or conversely avoid unexpected failures.
With Vibration Profile Design you can:
- Create an accelerated shaker test and assess the impact on shock and fatigue damage
- Rapidly compare an existing test specification with service vibration data
- Extend the life of parts in-service or avoid unexpected failures
- Understand the impact of exposure time in-service and on the test rig
