EFFECTS OF UNCERTAINTY REDUCTION ON WEIGHT OF COMPOSITE LAMINATES AT CRYOGENIC TEMPERATURES

摘要

The effect of uncertainty reduction measures on the weight of laminates for cryogenic temperatures is investigated. The uncertainties in the problem are classified as error and variability. Probabilistic design is carried out to analyze the effect of reducing the uncertainty on the weight. For demonstration, variability reduction takes the form of quality control, while error is reduced by including the effect of chemical shrinkage in the analysis. It is found that the use of only error control leads to 12% weight reduction, the use of only quality control leads to 20% weight savings and the use of error and variability control measures together reduces the weight by 37%. In addition, the paper also investigates how to improve the accuracy and efficiency of probability of failure calculations (performed using Monte Carlo simulation technique). Approximating the cumulative distribution functions for strains is shown to lead to more accurate probability of failure estimations than the use of response surface approximations for strains.