SELECTION OF STRUCTURAL PARAMETERS FOR CORRECTING FREQUENCY RANDOM ERRORS

This paper deals with the correction of random errors of structural fr equencies and the optimal selection of parameters to be modified. The concepts of ideal parameter to be modified, optimal parameter to be mo dified and the optimal parameter group (in which parameters to be modi fied are all optimal) are introduced. When the number of the parameter s to be modified is given, the optimal parameters are selected from al l design parameters so that the expectation of the root-mean-square of the corrected frequency errors takes its minimal value, and the modif ications of those optimal parameters are also obtained. The formula to calculate this minimal value is given. Furthermore, the minimal numbe r of parameters to be modified in the optimal parameter group is obtai ned when the number of parameters to be modified is unknown. Finally, a 15-element truss structure is used to illustrate the application of the proposed methods. Copyright (C) 1996 Elsevier Science Ltd.