simDefect: Local damage accumulation

In simLife: Simulation of Fatigue Lifetimes

Description

Simulate fatigue lifetime of the geometry system

Usage

simDefect(stress, S, CLT, opt)

Arguments

stress	stress level
S	non-overlapping geometry system
CLT	the start (initialized) cluster of objects
opt	control list of fixed parameters, see simTimes

Details

The function simulates the fatigue lifetime model for the given geometry system. The overall fatigue lifetime is determined by the first accumulated convex area of projected defects which exceeds the predefined critical area. The process of defect accumulation is based on the general results for VHCF fatigue behaviour of material structures published by Murakami. Here we treat two nearby defects as an enlarged common one if the weighted (single-linkage) Euclidean distance inbetween (in 3D) is less than some portion (possibly including some material specific constant) of the minimum of the corresponding square roots of projected defect areas. The weight is chosen as the reciprocal value of the cosine of the angle between the main load direction and the rotational axis of the chosen object having minimum distance to the compared defect . Further, the argument opt defines the list of controls of fixed parameters with the following elements: vickers Vickers hardness, distTol as a (proportion) factor of the minium the corresponding square roots of projected defect areas (might be less than 0.95 but in general depends on the inverstigated material structure), inAreafactor default set to value 1.56, outAreafactor default set to value 1.43, pointsConvHull number of sampling points of each objects projection border for approximating the defect projection convex area, scale scaling factor (should be set to 1e+06 for μ m^2), pl print level of information output with some verbose messages for any value larger than 100. In this case only the accumulated defect projections after adding the last individual failed object are returned. Here the last element contains the defect with the highest projected area which leads to the overall failure.

Value

list of clusters, the following values are returned for further analysis:

• id the object id numbers in the accumulated defect

• n internal: accumulated defect id, zero means last element of cluster

• B corresponding defect types of projected objects

• interior whether each object is interior or not

• A projected areas, possibly convex area

• inner whether the defect lies in the interior or not

• T random individual times

• label phase labels

• areaMax attribute, the maximum area of defect projections

• aIn attribute, critical area for inner defect projections

• aOut attribute, critical area for outer defect projections

• maxSize attribute, maximum number of projected objects found in a defect

Author(s)

M. Baaske

simLife documentation built on May 2, 2019, 6:36 a.m.