Procedure for Initializing Interface Stiffnesses Based on Sensitizing Inputs

摘要

Parameter identification and optimization procedures often fail when the target model responses are insensitive to variations in the selected design variables (e.g., Young's modulus, plate thickness, etc.) of the nominal model. This insensitivity simply indicates that the kinetic and strain energies associated with a group of elements relative to a given variable are negligible with respect to the total energies of the complete structure. Two independent conditions can lead to this situation. First, the model displacement fields are localized and do not attain the design variable in question. Second, the nominal properties of both the elements governed by the design variable and environing structure are such that no load paths cross through the zone in question. We are interested in determining the domain of sensitivity of a design variable so that it can be reinitialized in preparation for an optimization procedure. The proposed methodology is based on the application of sensitizing inputs and uses the ratio of local to global energies to redefined nominal stiffness properties. The procedure is validated with academic and industrial structures.