Ansys nCode DesignLife: Stress & Strain Based Fatigue Life Prediction

Ansys nCode DesignLife works with Ansys Mechanical to reliably evaluate fatigue life. Using the results of finite element analysis (FEA) from Ansys Mechanical and Ansys LS-DYNA, it accumulates damage from repetitive loading to determine a product’s predicted life. The new user interface provides an end-to-end solution within an integrated workflow and single interface: Strain Life (EN), Stress Life (EN), Dang Van, Safety Factor, Seam Weld, Spot Weld, Vibration Fatigue, Thermo-Mechanical Fatigue, Adhesives Bonds.

Ansys nCode DesignLife the FEA Results from Ansys, Abaqus, LS-Dyna and other solvers

Import the FEA Results from Ansys, Abaqus, LS-Dyna and other solvers

nCode DesignLife is a CAE-based fatigue analysis system that contains a comprehensive set of solvers and advanced methods for predicting structural durability from major finite element analysis (FEA) result files. It identifies critical locations and calculates realistic fatigue lives for both metals and composites. Design engineers can go beyond performing simplified stress analysis and avoid under- or over-designing products by simulating actual loading conditions to avoid costly design changes.

Stress-Life (SN) for high-cycle fatigue

The primary application of the Stress-Life (SN) method is high-cycle fatigue (long lives) where nominal stress controls the fatigue life. Includes the ability to interpolate multiple material data curves for factors such as mean stress or temperature. Further options are also provided to account for stress gradients and surface finishes. Python scripting is also available for defining custom fatigue methods and material models.

  • Material models: 
    • Standard SN
    • SN Mean multi-curve
    • SN R-ratio multi-curve
    • SN Haigh multi-curve
    • SN temperature multi-curve
    • Bastenaire SN
    • Custom SN using Python scripting
  • Stress combination methods or critical plane analysis
  • Back calculation to target life
  • Multiaxial assessment: 
    • Biaxial
    • 3D Multiaxial
    • Auto-correction



Ansys nCode DesignLife Fatigue Life Prediction Software
  • Mean stress corrections:
    • FKM Guidelines
    • Goodman
    • Gerber
    • Walker
    • Interpolate multiple curves
  • Notch correction:
    • Stress gradiant corrections
      • FKM Guidelines
      • User defined
    • Critical distance



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
Strain-Life (EN) for low-cycle fatigue

Fatigue analysis of seam welds

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



Fatigue analysis of spot welds in thin sheets

The Spot Weld option enables the fatigue analysis of spot welds in thin sheets. The approach is based on the LBF method (see SAE paper 950711) and is well-suited to vehicle structure applications.

  • Spot welds are modeled by:
    • Stiff beam elements (e.g., NASTRAN CBAR), as supported by many leading FE pre-processors
    • Supports CWELD and ACM formulations using solid element representation
  • Cross sectional forces and moments are used to calculate structural stress around the edge of the weld
  • Life calculations are made around spot weld at multiple angle increments and the total life reported includes the worst case
  • Python scripting enables modelling of other joining methods such as rivets or bolts
weld fatigue simulation FEA Ansys nCode DesignLife Software

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.



Frequency based vibration fatigue Ansys nCode DesignLife Software

High temperature fatigue and creep

The Thermo-Mechanical Fatigue (TMF) option provides solvers for high temperature fatigue and creep by using stress and temperature results from finite element simulations. Mechanical loads that vary at a different rate to the temperature variations can also be combined. Applications include components that are both mechanically and thermally loaded such as vehicle exhaust systems and manifolds.

High temperature fatigue methods:

  • Chaboche 
  • ChabocheTransient

Creep analysis methods:

  • Larson-Miller
  • Chaboche creep



Thermo-Mechanical Fatigue Creep simulation FEA Ansys nCode DesignLife Software

Stress-life fatigue of anisotropic materials

The Short Fibre Composite option uses stress-life fatigue calculations for anisotropic materials such as glass fibre filled thermoplastics. The stress tensor for each layer and section integration point through the thickness is read by DesignLife from FE results. The material orientation tensor describing the “fibre share” at each calculation point is provided by mapping a manufacturing simulation to the finite element model. This orientation tensor can be read from the FE-results file or supplied from an ASCII file.

Short Fibre Composite module features: 

  • Simulate complex loading scenarios using any time domain method (static or modal superposition, duty cycles, etc.)
  • Simulate vibration tests driven by random (PSD), swept sine, sine dwell or sine-on-random loading
  • Predict damage and life per layer and integration point
  • Incorporate results of manufacturing simulation including fibre orientation tensors or residual stresses
  • Model local fatigue properties based on microstructure (orientation tensor) and stress state
  • Calculate fatigue based on principal stresses or critical plane — including stresses calculated from FE-Digimat and multiaxial stress states
  • Choice of fatigue property model – SN curve interpolation or interface to Digimat
  • Use of homogenized matrix or fibre stresses as well as typical composite ones





Composite Fatigue simulation FEA Ansys nCode DesignLife Software


We pride ourselves on empowering each client to overcome the challenges of their most demanding projects.

Enteknograte offers a Virtual Engineering approach with FEA tools such as MSC Softwrae(Simufact, Digimat, Nastran, MSC APEX, Actran Acoustic solver), ABAQUS, Ansys, and LS-Dyna, encompassing the accurate prediction of in-service loads, the performance evaluation, and the integrity assessment including the influence of manufacturing the components.

Creep and Creep-Fatigue Interactions

considering Creep-Fatigue interaction in high temperature simulations identifies whether fatigue and/or creep are the dominant damaging mechanisms, thus allowing re-design to focus on the relevant damage mechanisms and significantly reduce pre-service component testing.

Vibration Fatigue Finite Element Simulation: Time & Frequency Domain

Structural vibration can be a source for many product related problems; it can cause fatigue and durability problems as well as adverse reactions to the user or bystanders in the form of undesirable vibrations that can be felt or heard. As well, undesired structural vibrations can prevent products from operating as required and potentially becoming a safety concern. The Vibration Fatigue simulation predict fatigue in the frequency domain and it is more realistic and efficient than time-domain analysis for many applications with random loading such as wind and wave loads.

Fatigue Analysis of Welded Structures Using the Finite Element Method

Enteknograte use advanced Numerical simulation software and methods to simulate the welding behavior in real service load condition and estimate its Durability and Fatigue Life with Ansys Ncode, Simulia FE-Safe, MSC CAEFatigue and FEMFAT. The Seam Weld and Spot Weld fatigue simulation enables the fatigue analysis of joints including different type of welding such as fillet, overlap, spot welds in thin sheets and laser welded joints.

Finite Element Analysis of Durability and Fatigue Life

Vibration Fatigue, Creep, Welded Structures Fatigue, Elastomer and Composite Fatigue with Ansys Ncode, Simulia FE-Safe, MSC CAEFatigue, FEMFAT
Durability often dominates development agendas, and empirical evaluation is by its nature time-consuming and costly. Simulation provides a strategic approach to managing risk and cost by enabling design concepts or design changes to be studied before investment in physical evaluation. The industry-leading fatigue Simulation technology such as Simulia FE-SAFE, Ansys Ncode Design Life and FEMFAT used to calculate fatigue life of multiaxial, welds, short-fibre composite, vibration, crack growth, thermo-mechanical fatigue.

Elastomer Materials Fatigue Finite Element Analysis​

Developers of rubber materials, components and systems increasingly rely on simulation as a routine means to address design issues. For metallic components, solutions for fatigue analysis from FEA have existed commercially for many years and have become an essential part of maturing and qualifying design concepts in many industrial sectors. Using modern multiaxial strain based fatigue methods enable us to simulate the fatigue analysis of elastomer materials and Rubber.

Composites Fatigue Finite Element Simulation

The structural durability of a component is one of the most expensive attributes to test, thus one of the most appealing for CAE. Fatigue modeling of chopped and continuous fiber polymer composites is challenging due to their anisotropic, heterogeneous and viscous material properties as well as their process-dependent microstructure. For simulation of high cycle fatigue (HCF) of fiber reinforced composites we use FEA tools Like VirtualLab Durability, nCode DesignLife , MSC CAEFatigue and FE-SAFE.

Additive Manufacturing and 3D Printing

FEA Based Design and Optimization with Simufact, Abaqus, ANSYS and MSC Apex for powder bed fusion (PBF), directed energy deposition (DED) and binder jetting processes
With additive manufacturing, the design is not constrained by traditional manufacturing requirements and specific number of design parameters. Nonparametric optimization with new technologies such as Artificial Intelligence in coupled with Finite Element method, can be used to produce functional designs with the least amount of material. Additive manufacturing simulations are key in assessing a finished part’s quality. Here at Eneteknograte, dependent of the problem detail, we use advanced tools such as MSC Apex Generative Design, Simufact Additive, Digimat, Abaqus and Ansys.

Thermal Stress and Fatigue Simulation: Coupled CFD and Finite Element Approach

Enteknograte’s Engineering Team provides a comprehensive Steady-State and Transient CFD Thermal Analysis & Design services using MSC Cradle, Siemens Star-ccm+, OpenFoam and Ansys Fluent Flow Simulation. CFD Thermal Analysis extends the capability of FEA thermal analysis with MSC Nastran, Abaqus and LS-Dyna by replacing the simplistic convection boundary conditions with direct calculations of the heat transfer coefficients based on the fluid flow properties and is often referred to a conjugate heat transfer analysis.

Hydrodynamics CFD simulation, Coupled with FEA for FSI Analysis of Marine and offshore structures

Transient Resistance, Propulsion, Sea-Keeping and Maneuvering Simulation, Cavitation, Vibration and Fatigue
Hydrodynamics is a common application of CFD and a main core of Enteknograte expertise for ship, boat, yacht, marine and offshore structures simulation based design. Coupling Hydrodynamic CFD Simulation in Ansys Fluent, Siemens Star-ccm+ and MSC Cradle with structural finite element solver such as Abaqus and Ansys, enable us to Simulate most complicated industrial problem such as Cavitation, Vibration and Fatigue induced by hydrodynamics fluctuation, Transient Resistance, Propulsion, Sea-Keeping and Maneuvering Simulation, considering two way FSI (Fluid Structure Interaction) coupling technology.

Integrated Artificial Intelligence (AI) & Machine Learning - Deep Learning with CFD & FEA Simulation

Machine learning is a method of data analysis that automates analytical model building. It is a branch of Artificial Intelligence based on the idea that systems can learn from data, identify patterns and make decisions with minimal human intervention. With Artificial Intelligence (AI) applications in CAE, that is Mechanical Engineering and FEA and CFD Simulations as design tools, our CAE engineers evaluate the possible changes (and limits) coming from Machine learning, whether Deep Learning (DL), or Support vector machine (SVM) or even Genetic algorithms to specify definitive influence in some optimization problems and the solution of complex systems.

Acoustics and Vibration: FEA and CFD for AeroAcoustics, VibroAcoustics and NVH Analysis

Noise and vibration analysis is becoming increasingly important in virtually every industry. The need to reduce noise and vibration can arise because of government legislation, new lightweight constructions, use of lower cost materials, fatigue failure or increased competitive pressure. With deep knowledge in FEA, CFD and Acoustic simulation, advanced Acoustic solvers and numerical methods used by Enteknograte engineers to solve acoustics, vibro-acoustics, and aero-acoustics problems in automotive manufacturers and suppliers, aerospace companies, shipbuilding industries and consumer product manufacturers.

Heat Transfer and Thermal Analysis: Fluid-Structure Interaction with Coupled CFD and Finite Element Based Simulation

We analyze system-level thermal management of vehicle component, including underhood, underbody and brake systems, and design for heat shields, electronics cooling, HVAC, hybrid systems and human thermal comfort. Our Finite Element (LS-Dyna, Ansys, Abaqus) and CFD simulation (Siemens Start-ccm+, Ansys Fluent , Ansys CFX and OpenFoam) for heat transfer analysis, thermal management, and virtual test process can save time and money in the design and development process, while also improving the thermal comfort and overall quality of the final product.

Multibody Dynamics

Robots Dynamics, Control Systems, Advanced Machinery, Full Vehicle MBD and NVH
Multibody dynamic analysis is important because product design frequently requires an understanding of how multiple moving parts interact with each other and their environment. From automobiles and aircraft to washing machines and assembly lines - moving parts generate loads that are often difficult to predict. Complex mechanical assemblies present design challenges that require a dynamic system-level analysis to be met. Accurate modeling can require representations of various types of components, like electronic controls systems and compliant parts and connections, as well as complicated physical phenomena like vibration, friction and noise.

Finite Element Simulation of Crash Test and Crashworthiness with LS-Dyna, Abaqus and PAM-CRASH

Crashworthiness focuses on occupant protection to reduce the number of fatal and serious injuries. This research is responsible for developing and upgrading test procedures for evaluating motor vehicle safety. Crashworthiness research encompasses new and improved vehicle design, safety countermeasures and equipment to enhance occupant safety. Finite Element Analysis (FEA) has been the trend in virtual crash design over the last decade. The predictive capabilities of FEA allow engineers to fully understand a crash event in a virtual environment, thus limiting the number of physical tests that need to be executed and thus saving costs.