simLife (version 0.3)

simFracture: Fatigue lifetime simulation

Description

Simulation of fatigue lifetime model

Usage

simFracture(stress, S, opt, param, last.defect = FALSE, CL = NULL)

Arguments

stress

applied stress level

S

non-overlapping geometry system

opt

control list for simulation of individual failure times

param

parameter list for generating individual failure times

last.defect

logical, last.defect=FALSE (default), return either all defect accumulations or only the last one

CL

optional, NULL (default), predefined clustered regions of objects

Value

a list made up of the following objects if last.defect=FALSE (default):

• fracture return value of simDefect

• times return value of simTimes

• cl_info additional cluster information of responsible defect cluster

otherwise only cl_info is returned.

Details

We provide a wrapper function for simDefect to simulate the proposed fatigue lifetime model including the generation of individual failure times with additional information of the responsible accumulated defect projection area (simply called defect area) which leads to the failure of the system. This information is returned in the following list with elements: crack the responsible defect itself, T the individual failure times of objects aggregated as a cluster of objects, ferrit whether any secondary phase (here called ferrit) is involved for overall failure, interior whether the defect occurs in the interior or at the boundaries of the simulation box. The optional list argument CL defines clustered regions, see simCluster, of objects sticking together more close than others. This is useful in case one also wishes to model densely lieing agglomerations of objects (i.e. clusters of particles or fibers) as an obvious phenomenon of some specimen in mind. This list is made up of the following elements: id, the id of the region, center the center point of the corresponding region, r the radius (as the Euclidean distance from the center point) which within all objects belong to this region, interior whether any object within radius r hits the box boundaries of the simulation box.

Examples

# NOT RUN {
## Load a particle system
## and simulate its defect accumulation

## primary reinforcement (fibres)  and secondary phase (ferrit)
data(AL2MC_15p_k10_F2p_S)  # loading SF

## locally clustered spatial domains
data(AL2MC_15p_k10_F2p_CL) # loading CLF

## the box is stored together with the geometry system
box <- attr(SF,"box")

## generate individual failure times
opt <- list("vickers"=107,"distTol"=1,"Tmax"=10^11,
		"inAreafactor"=1.56, "outAreafactor"=1.43,
		"pointsConvHull"=10, "scale"=1e+06,"pl"=0)

par <- list("P"=c(0.01,10,0.5,80,-15,2),
		"F"=c(0,0,0,105,-12,1),
		"const"=list("Em"=68.9,"Ef"=400,"nc"=28.2,"nu"=0.33,
				"pf"=0.138,"nE"=NULL,"sigref"=276,"Vref"=5891))


# stress amplitude applied
stress <- 120
## generate individual (particles') failure times
CLT <- simTimes(SF,par,vickers=opt$vickers,stress=stress)

T <- unlist(sapply(CLT,`[[`,"T"))
V <- unlist(sapply(CLT,`[[`,"V"))
U <- unlist(sapply(CLT,`[[`,"U"))

## show estimated densities
showDensity(list("Delamination"=log10(V),"Crack"=log10(U),"Time"=log10(T)),xlim=c(-2,15))


## run accumulation
RET <- simDefect(stress,SF,CLT,opt)

#### alternatively run
#SIM <- simFracture(stress,S,opt,par,last.defect=FALSE,CL=CL)
#SIM$cl_info
####

## some simple analysis
LR <- RET[[length(RET)]]
isInCluster <- any(unlist(lapply(CLF,function(x,y)
					any(y$id %in% x$id) , y=LR)))
cat("Broken cluster: ", isInCluster,"\t Ferrit: ",
	any("F" %in% LR$label),"\t Acc.size",length(LR$id),"\n")

## select only clusters of size larger than 'msize'
msize <- 1
id <- sapply(RET,function(x) ifelse(length(x$id)>msize,TRUE,FALSE))
cat("Number of defect projections in last cluster: ",length(RET[[length(RET)]]$id),"\n")

## draw all accumulation paths until failure
dev.new()
L <- plotDefectAcc(RET,last.path=FALSE)

## plot last
## get particle id numbers of last cluster
# qid <- LR$id
# cylinders3d(SF[qid],box=box, col=c("#0000FF","#00FF00","#FF0000","#FF00FF"))
## drawing only last cluster leading to failure
# drawDefectProjections(SF,list(LR))
# }