This paper presents a study on the uncertainty in material parameters of wave
propagation responses in metallic beam structures. Special effort is made to
quantify the effect of uncertainty in the wave propagation responses at high
frequencies. Both the modulus of elasticity and the density are considered
uncertain. The analysis is performed using a Monte Carlo simulation (MCS)
under the spectral finite element method (SEM). The randomness in the
material properties is characterized by three different distributions, the normal,
Weibull and extreme value distributions. Their effect on wave propagation
in beams is investigated. The numerical study shows that the CPU time
taken for MCS under SEM is about 48 times less than for MCS under a
conventional one-dimensional finite element environment for 50 kHz loading. The
numerical results presented investigate effects of material uncertainties on high
frequency modes. A study is performed on the usage of different beam theories
and their uncertain responses due to dynamic impulse load. These studies
show that even for a small coefficient of variation, significant changes in the
above parameters are noticed. A number of interesting results are presented,
showing the true effects of uncertainty response due to dynamic impulse
load.
Keywords
MCS, SEM, normal distribution, Weibull distribution,
extreme value distribution, wavenumber, group speeds
