Abstract
This paper presents a procedure for the analysis of natural frequencies of finite element models with uncertain parameters. The uncertain model parameters are modeled with fuzzy numbers and then the uncertain natural frequencies are calculated by a fuzzy approach based on interval arithmetic. To obtain accurate intervals of natural frequencies, the interchange of mode shapes must be detected accurately. For this, a mode identification technique based on the MAC-value is proposed. The examples show that the procedure accurately produces the ranges of natural frequencies using the mode identification technique. In addition, the MAC-value can be used as an indicator for the proper number of α -cut levels.
