simLife-package: Simulation of Fatigue Lifetimes
In simLife: Simulation of Fatigue Lifetimes

Description Details References

Provides methods for simulation and analysis of a very general fatigue lifetime model for (metal matrix) composite materials.

These materials are usually made up of some reinforcement primary phase and a secondary phase which is generally considered to have negative properties with regard to the overall lifetime. A spatial geometric particle model [3,4] can be simulated according to some predefined distributional assumptions and then taken as an input to the simulation routine of the fatigue lifetime model. The distributional model parameters of the lifetime model are specified by the user and usually have to be estimated based on experimental data in general. The lifetime model roughly consists of two parts. First, a random individual failure time for all particles is generated based on two types of projected defects (square root projection areas) dependent on the considered joint size-shape-orientation distribution of the whole particle system. Second, a deterministic projected defects accumulation procedure is applied to find the most hazardous defect region which could lead to an overall failure of the specimen in a real life situation. Additionally we distinguish between particles which are hosted fully inside the material and those lying near the surface. Further, the lifetime model also allows for the inclusion of predefined densely clustered regions of particles which can be simulated beforehand. The user may also provide particular material constants such as Vickers hardness and others according to the phenomenological properties of specific material structures and for appropriateness of the lifetime model simulations. As an add-on hardcore particle packings can be generated by the well-known Random Sequential Adsorption (RSA) algorithm.

The high level functions simFracture, woehler and woehlerDiagram are intended as a simple introduction to utilizing the package.

Y. Murakami (2002). Metal Fatigue: Effects of Small Defects and Nonmetallic Inclusions. Elsevier, Amsterdam.
J.W. Evans. Random and cooperative sequential adsorption. Rev. Mod. Phys., 65: 1281-1304, 1993.
M. Baaske, A. Illgen, A. Weidner, H. Biermann, F. Ballani (2018). Influence of ceramic particle and fibre reinforcement in metal-matrix-composites on the VHCF behaviour. Part I: Stochastic modelling and statistical inference. In: Christ, H.-J. (ed.), Fatigue of Materials at Very High Numbers of Loading Cycles. Experimental Techniques - Mechanisms - Modeling and Fatigue Assessment. Springer Spektrum, Wiesbaden, pp. 319-342.
M. Baaske, A. Illgen, A. Weidner, H. Biermann, F. Ballani (2018). Influence of ceramic particle and fibre reinforcement in metal-matrix-composites on the VHCF behaviour. Part II: Stochastic modelling and statistical inference. In: Christ, H.-J. (ed.), Fatigue of Materials at Very High Numbers of Loading Cycles. Experimental Techniques - Mechanisms - Modeling and Fatigue Assessment. Springer Spektrum, Wiesbaden, pp. 295-318.