Modeling error assessment of reduced-order finite element models for SHM: A case study of Milad Tower

Abstract

Abstract Condition assessment, model updating, and basic studies of large and complex structures subjected to static and dynamic loadings necessitate establishing a reasonably low order model to enhance computational efficiency. An essential requirement for the development of a low-order model is to preserve the main characteristics of the full-scale model within the frequency range of interest or the desired static and/or dynamic response. In this regard, a novel reduced-order model (ROM) is developed based on a full-scale model (FSM) built using commercial finite element analysis software. Utilizing the common lumped mass matrix can introduce mass modeling errors. Hence, a method is proposed to extract the reduced consistent mass matrix model (RCMM) for use in the ROM. The modeling errors in the proposed ROM is studied for comparison with the static and dynamic responses. It can curtail capability of parameter estimation to capture the physical behavior of the structure using the ROM. Modeling error simulations prior to actual field-testing is highly recommended to determine the feasibility of non-destructive tests for successful system identification. The Milad telecommunication tower is the sixth tallest tower in the world, with a height of 435 meters. Using the proposed method, the consistency of the generated ROM based on the RCMM is verified with the Milad Tower’s FSM. In this regard, displacements due to equivalent static wind loads, natural frequencies, mode shapes, slopes of mode shapes, and time history response for earthquake loading are compared. The proposed ROM assessments utilizing RCMM confirm the accuracy of the static and dynamic characteristics.