simu_failTime {abcADM}R Documentation

Simulate samples of failure time using parameters θ

Description

Simulate n observations of failure time from θ = (μ_a, σ_a, μ_b, σ_b, μ_c, σ_c, μ_n, σ_n, μ_σ0 , σ_σ0) for constant load test or ramp load test.

Usage

simu_failTime(paras, n, tau_c, t_c, verbose = FALSE)

Arguments

paras

either a vector or a matrix where each row is θ

n

number of samples

tau_c

constant load level (can be set to infinity for ramp load test)

t_c

ending time of the constant load test in hours (can be set to infinity for ramp load test)

verbose

print information messages to console if TRUE

Details

* The default θ is provided and can be invoked via default_param.

* When sample pieces are subject to the load profile

τ(t) = kt if t <= T_0

τ(t) = τ_c if t > T_0

where τ_c is the selected constant-load level under the ramp-loading rate k, and T_0 is the time required for the load to reach τ_c under the ramp-loading rate k.

* The constant load level is assumed to be reached at the ramp-loading rate (k). The ramp-loading rate is 388,440 psi/hour.

Utilizes routines from the BRENT C++ root-finding library.

Value

Return a matrix of failure times. Each column contains samples from one θ. The name of the output matrix must be in the format "ID_τ_c_t_c(in years)", e.g. simuConstLoad_4500_1Y.

References

Brent, R. (2002). Algorithms for Minimization without Derivatives. Dover. ISBN: 0-486-41998-3.

Yang, C. H., Zidek, J. V., & Wong, S. W. (2019). Bayesian analysis of accumulated damage models in lumber reliability. Technometrics, 61(2), 233-245.

Examples

# simulate data with constant load 4500 psi and test of duration 1Y (8760 hours)
simuConstLoad_4500_1Y = simu_failTime(default_param, 30, 4500, 8760, TRUE)

# simulate data for ramp load
simuRampLoad_Inf_1Y = simu_failTime(default_param, 30, Inf, 8760)



[Package abcADM version 1.0 Index]