Finite element calibration for structural load identification

Inventors

Wu, Zheng Yi • Yin, Peng • Elhaddad, Wael

Assignees

Bentley Systems Inc

Abstract

In various example embodiments, model calibration techniques are used to identify one or more external structural loads on a structure. Initially, material or geometry attributes of elements of a model are adjusted to minimize discrepancy between measured responses and modeled responses. Thereafter, the model is used to search for external structural loads that minimize discrepancy between the measured responses and the modeled responses. Discrepancy may be measured by an error function that looks to dynamic responses and/or static responses. A solution that minimizes discrepancy may be determined using a genetic algorithm that generates a set of proposed external structural loads, applies the set to the model to produce the modeled responses, computes an error function that measures the difference between the measured responses and the modeled responses, and evolves the solutions to minimize an error produced by the error function, with such operation proceeding until a stopping criteria is reached.

Core Innovation

A method identifies one or more unidentified external structural loads by accessing a model of a structure that includes a plurality of elements and by measuring sensor responses to one or more known external structural loads during a calibration phase. The model is calibrated during the calibration phase by adjusting material or geometry attributes of the plurality of elements to minimize discrepancy between measured responses and modeled responses of the calibration phase.

During an operational phase when the structure is subject to one or more unidentified external structural loads, the method measures responses to the unidentified loads and searches, using the calibrated model, for a set of external structural loads between a minimum limit of structural load and a maximum limit of structural load that minimize a discrepancy between the measured responses and modeled responses in the operational phase. The searching generates a set of proposed external structural loads, produces modeled responses from the calibrated model, measures the discrepancy, and uses the genetic algorithm to evolve the set over a plurality of iterations to reduce the discrepancy until a stopping criteria is reached.

The method returns the set of proposed external structural loads when the stopping criteria is reached and displays indications of the set of external structural loads as identified external structural loads on the structure. In the context of a bridge or building, the approach includes displaying indications of progress of the calibration on a display screen and determining whether the identified external structural loads are compliant with limits to ensure safety.

Claims Coverage

Independent claims cover four inventive features: calibrated structure modeling, genetic algorithm-based discrepancy-minimizing search for load sets within limits, displaying identified loads, and, for the bridge/building claim family member, calibration progress display with a safety/compliance determination.

Across the independent claims, the inventive scope centers on calibrating a structure, bridge, or building model using sensor responses to known loads to minimize discrepancy, then using a genetic algorithm-based search within minimum and maximum load limits to find external structural load sets that minimize discrepancy between measured responses and modeled responses until a stopping criteria is reached, followed by displaying identified loads. For the bridge/building claim, the method additionally displays calibration progress and determines compliance with limits to ensure safety.

Stated Advantages

Documented Applications