Ansys nCode DesignLife
Stress & Strain Based Fatigue Life Prediction

Ansys nCode DesignLife, the industry-leading tool for durability analysis, gives you a comprehensive diagnostic fatigue process to predict your product’s operational lifetime.

Optimize Product Fatigue Life for Expected Use Scenarios

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. You can quickly evaluate the effects of different materials and alternative geometries for new designs, and then optimize them for the product’s expected usage — long before the first prototype is built or expensive testing takes place.

Unparalleled Accuracy and Technology
Reduce Overall Product Development & Validation Cost
Simulation-Led Design to Reduce Reliance on Physical Test
Flexible and Easy-to-Use User Interface

Quick Specs

Ansys partnered with HBK to bring unparalleled simulation-based durability technology to Ansys Workbench, providing end-to-end solutions for customers finding fatigue failure a key challenge.

Stress life (SN)
Strain life (EN)
Vibration and fatigue
Thermal Mechanical Fatigue

Seam Welds
Spot Welds
Material Management
Vibration Manager

Virtual Strain Gauge and Virtual Sensor
FEA Display
Crack growth
Customization

Designing So Cool Heads Prevail

Ural Diesel-Motor Works uses multiphysics simulation to avoid thermal cracking in a cylinder head

The new cylinder head design delivers the long life and high quality that the company’s customers have come to expect.

View Case Study

Ural Diesel-Motor Works needed to upgrade a locomotive engine made decades before. The aluminum cylinder heads were cracking near the injector as water leaked, mixing with fuel to cause the engine to stop running. Ural turned to Ansys for simulation software to replicate the head’s internal geometry and simulate fluid flow.

Engineers created a structural model and added mechanical loading, temperature fields, thermal stresses, temperature loads and pressures generated during the engine’s working cycle. Using several load cases, they calculated a complete range of stresses to clearly identify the root cause of the cracking and then create a solution by using the modeling to determine the cast iron needed to replace aluminum. Ansys nCode DesignLife captured the data, data flow and parameters in the Ansys Workbench integrated environment and performed a comprehensive fatigue analysis using the stress-life approach, giving Ural a successful solution.

Understand and Simulate Fatigue Early in the Design Process

Ansys nCode DesignLife works with Ansys Mechanical and Ansys LS-DYNA to reliably evaluate fatigue life. You can quickly evaluate the effects of different materials and alternative geometries for new designs, and then optimize them for the product’s expected usage before a costly prototype.

With a new interface on the Ansys Workbench, you can enjoy a customized workflow that integrates with other products while staying within a single interface. You also have the flexibility to access your nCode user interface directly from Ansys Workbench. The ease-of-use makes the power of nCode DesignLife even easier to realize.

Key Features

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

Strain Life (EN)

Strain-Life is applicable to a wide range of problems, including low-cycle fatigue (LCF) where 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 and the number of cycles to failure.

Stress Life (SN)

This is primarily applicable to high-cycle fatigue (HCF) where nominal stress controls the fatigue life.

A wide range of methods are provided for defining the SN curves, including 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.

Dang Van

Multiaxial fatigue limit criterion is used to predict the endurance limit under complex loading situations.

Output is the safety factor. The program uses material parameters calculated from tensile and torsion tests. Account for manufacturing effects by using equivalent plastic strain in the unloaded component.

Safety Factor

Evaluate stress-based factors of safety and standard mean stress corrections or user-specified Haigh diagrams to assess durability.

This is widely used as a key design criterion for engine and powertrain components.

Seam Weld

Simplifies the process of setting up fatigue analysis of seam welds by intelligently identifying weld lines in the FEA Model.

Covers seam welded joints including fillet, overlap and laser welded joints. Stresses can either be taken directly from FEA models (shell or solid elements) or calculated from grid point forces or displacements at the weld. The approach is appropriate for weld toe, root and throat failures.

Spot Weld

Enables fatigue analysis of spot welds in thin sheets. Cross sectional forces and moments are used to calculate structural stress around the edge of the weld.

Life calculations are made around a spot weld at multiple angle increments and the total life reported includes the worst case. Python scripting enables modeling of other joining methods such as rivets or bolts.

Vibration Fatigue

The Vibration Fatigue option enables the simulation of vibration shaker tests driven by random (PSD), swept-sine, sine-dwell or sine-on-random loading.

It provides the capability to predict fatigue in the frequency domain and is more realistic and efficient than time-domain analysis for many applications with random loading, such as wind and wave loads.

Thermo-Mechanical Fatigue

Components in high-temperature operating environments such as engine pistons, exhaust systems and manifolds can suffer from complex failure modes.

The Thermo-Mechanical Fatigue (TMF) option provides solvers for high-temperature fatigue and creep by using stress and temperature results from finite element simulations. TMF includes high temperature fatigue methods Chaboche and Chaboche Transient. Creep analysis methods include Larson-Miller and Chaboche creep.

Adhesive Bonds

Enables fracture-mechanics-based method to assess which joints in the structure are most critically loaded.

The adhesive bonds option enables durability calculations on adhesive joints in metallic structures. Adhesive bonds are modeled with beam elements and grid point forces are used to determine line forces and moments at the edge of the glued flange. Approximate calculations of the strain energy release rate are made at the edge of the adhesive and, by comparison to the crack growth threshold, a safety factor is calculated.

NCODE RESOURCES & EVENT

Featured Webinars

On Demand Webinar

Suffering from Fatigue? Learn About Durability with Ansys

The Ansys platform is focused on an easy-to-use single UI, integration with industry-leading products and native automation.

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On Demand Webinar

How to Assess and Prevent High-Cycle Fatigue Failure

Learn how Ansys Mechanical and Ansys nCode DesignLife can help ensure designs — early in development — meet fatigue specifications and will continue to perform beyond the warranty period.

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