world’s first code for elastomer fatigue life simulation

Endurica LLC was founded in 2008 to provide services, technology, and training that accelerate reliable design for elastomer materials and components. We use the Endurica fatigue life prediction code – a patented system for analyzing the effects of multiaxial, variable amplitude duty cycles on elastomers. Endurica is the world’s first code for elastomer fatigue life simulation. We strive to make CAE-based fatigue life prediction for rubber as widely practiced and as well-understood as fatigue life prediction for other materials by empowering materials, component, and system developers with reliable methods and tools for assessing fatigue life. Our solutions help our clients understand and manage the effects on fatigue life of nonlinear material behavior, component geometry, and complex duty cycles. Endurica has served leading companies in the automotive, defense, medical device, offshore, and consumer products.

Endurica is the industry leading solution for rubber fatigue analysis.

Contours of fatigue life show the number of repeats of the displacement history that will be endured before cracks appear.

Contours of computed fatigue life in a truck tire for straight-ahead rolling conditions.

Founder & Developer

Dr. Will Mars is an international leader in the failure mechanics of rubber. He has received several awards for his scientific contributions and innovations, including the 2007 Sparks Thomas award of ACS Rubber Division, and the 1999 Henry Fuchs award of SAE Fatigue Design & Evaluation committee.

Dr. Mars is the editor of the journal Rubber Chemistry & Technology, and past editor of Tire Science & Technology with 40+ peer-reviewed publications and a patent. His experiences and contributions span a topic range including material characterization, product evaluation, constitutive modeling, crack nucleation, fracture mechanics and fatigue life prediction methods.

He has more than 20 years’ experience developing testing and simulation methods in the rubber industry. Dr. Mars’ professional activity has focused generally on applying experimental and computational mechanics in pursuit of better-performing rubber products. He has taught graduate courses as an adjunct professor at the University of Toledo in continuum mechanics and fracture mechanics. He has been an invited lecturer in numerous international venues. Dr. Mars earned his Honors BSME with Polymer Specialization at the University of Akron, and his MS and Ph.D. degrees at the University of Toledo. Dr. Mars is the author of the Endurica fatigue life solver – the world’s first commercially available simulation for fatigue analysis of rubber. As founder and president of Endurica LLC, he promotes use of the simulation software worldwide through lectures and workshops.

Critical Plane Analysis

Critical plane analysis enables accurate calculation of the effects of multiaxial loading on fatigue performance. The analysis considers how a series of potential microcracks will experience the 6 components of the stress tensor. Each potential microcrack is identified by its unit normal vector, and the set of all unit normals is represented as a sphere colored according to the life computed for each normal. The shortest life among all of the normals (colored red in the image) is reported as the fatigue life and its location on the sphere shows the plane on which cracks first initiate. We developed and patented the first critical plane analysis for elastomers. Our algorithm considers the effects of finite straining and of crack closure.

Rainflow Counting

Rainflow counting considers how variable amplitude loading will influence fatigue performance. The load signal experienced by each microcrack is first obtained via critical plane analysis. It is then parsed into a list of discrete events. Each event contributes to the total rate of crack development according to the crack growth rate law of the material. Our implementation includes an index back into the original time domain signal, so that the most damaging events can be quickly identified.

Nonlinear Material Behavior

Elastomers exhibit a rich set of behaviors. Physically realistic, nonlinear models are provided in our fatigue solver to represent cyclic stress-strain behavior, strain crystallization effects (or lack of), and time and temperature dependence. For each behavior, both minimalistic and high accuracy models are provided, giving analysts a high degree of control over analysis scope and accuracy.

Fatigue Testing Methods

Our 3rd generation testing methods reflect the state of the art in fatigue testing for elastomers. Traditional fatigue testing methods offer too little control over execution time and data scatter, and they indiscriminately confound various influences on fatigue performance. Our testing methods are designed to produce accurate results within a pre-specified time budget. They are physics-based and are optimized to give the best possible observation of each factor governing fatigue performance.





Whether you seek higher durability, or lower cost without compromising durability, Endurica’s Fatigue Property Mapping™ service offers you a comprehensive inventory of the fatigue capabilities of your material. Get durability right in your development and analysis projects with our uniquely efficient, reliable, and physics-based testing protocols.

Success is riding on your compound. Don’t leave its fatigue behavior uncharted… Our characterization service offers the following test modules for probing each of the behaviors that govern your material’s fatigue performance.

Start a project with ENDURICA CL, Ask for Demo & Free Trial


Engineers increasingly call on numerical simulation to solve design issues. Simulation provides a tired-and-true approach to evaluating design features before risking investment in physical evaluation. Endurica’s fatigue simulation software gives you the tools you need to get durability right, before you build and break.

Analyze fatigue performance of your Finite Element Model…

Endurica’s fatigue solver shows how your design will endure in specific application scenarios.

Endurica is the industry leading solution for rubber fatigue analysis.


  • Save the costs of build and break experiments for well-qualified designs.
  • Quickly see how changes to material behavior, part geometry, or load history influence fatigue life.
  • Inform design decisions with a patented tool that has been continuously developed for more than a decade, and successfully validated against a wide range of benchmarks and real-world problems.
  • Find out where your part might develop a crack, how long it can be expected to endure, which events are damaging and which are harmless.
  • Communicate effectively about durability issues with realistic, physics-based presentation of simulation results.