Calculation time optimization for stochastic analysis of an industrial structure

Abstract

-Dynamic analysis of industrial structures may be costly from a numerical point of view. Thus, the need and the importance of reducing the size of the problem become obvious. One of the main hypothesises in the use of component mode synthesis method is that the model is deterministic. That is to say the parameters used in the model have defined and fixed values. Furthermore, carrying out the structure's response involving uncertain material, geometrical parameters, limit conditions, manufacturing tolerances and/or loading conditions is essential in a global design process. Our main aim in the present work is to test and validate a method which consists in condensing the system (i.e. to reduce the number of unknowns) and carrying out the stochastic study with a noniterative method. This method makes it possible to solve these problems without using the classical method whereby a direct modal calculation combined with the Monte Carlo simulation is made. The classical method is by nature iterative and hence CPU intensive. A propeller is taken as an example in order to validate the proposed methods. The results obtained agree well with references results and show the effectiveness of the proposed method.

Optimization Safety Factors to Study an Ultrasonic Motor

“…Recently, the enhanced hybrid mean value method is proposed to improve numerical stability and efficiency in the Most Probable Point (MPP) search [9]. The major difficulty lies in the evaluation of the probabilistic constraints, which is prohibitively expensive and even unpractical for many applications [10].…”

“…In general, when considering the normal distribution law, the normalized variable u i is given by: (10) where y i is the component of the vector y. The standard deviation σ i can be related to the mean value m i by: (11) We introduce the safety factors corresponding to the design variables x i .…”