Amirabbas Haidarpour, Kong Fah Tee^*

Structural Durability & Health Monitoring, Vol.14, No.1, pp. 1-17, 2020, DOI:10.32604/sdhm.2020.08792

Abstract This paper provides a model updating approach to detect, locate, and characterize damage in structural and mechanical systems by examining changes in measured vibration responses. Research in vibration-based damage identification has been rapidly expanding over the last few decades. The basic idea behind this technology is that modal parameters (notably frequencies, mode shapes, and modal damping) are functions of the physical properties of the structure (mass, damping, and stiffness). Therefore, changes in the physical properties will cause changes in the modal properties which could be obtained by structural health monitoring (SHM). Updating is a process fraught with numerical difficulties. These… More >

Siyang Piao¹, Huajiang Ouyang^{1, 2}, Yahui Zhang^{1, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.2, pp. 571-591, 2020, DOI: 10.32604/cmes.2020.08789

Abstract A beam approximation method for dynamic analysis of launch vehicles modelled as stiffened cylindrical shells is proposed. Firstly, an initial beam model of the stiffened cylindrical shell is established based on the cross-sectional area equivalence principle that represents the shell skin and its longitudinal ribs as a beam with annular cross-section, and the circumferential ribs as lumped masses at the nodes of the beam elements. Then, a fine finite element model (FE model) of the stiffened cylindrical shell is constructed and a modal analysis is carried out. Finally, the initial beam model is improved through model updating against the natural… More >

Leandro Fleck Fadel Miguel¹, Letícia Fleck Fadel Miguel²

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 249-270, 2012, DOI:10.32604/sdhm.2012.008.249

Abstract Model updating may be defined as an adjustment on the FE model through modal parameters experimentally obtained, in order to better represent its dynamic behavior. From this definition, structural health monitoring (SHM) methods can be considered closely related with these procedures, because it refers to the implementation of in situ non-destructive sensing and analysis of the dynamic system characteristics, which aims to detect changes that could indicate damage. Within this context, the present paper evaluates an iterative model updating approach when it is subjected to experimental vibration data. In addition, after getting the experimental adjusted model, a numerical damage detection… More >

Soojin Cho¹, Jin-Hak Yi², Chung-Bang Yun¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.4, pp. 151-152, 2009, DOI:10.3970/icces.2009.012.151

Abstract The bridges are exposed to severe operational and environmental loadings, such as traffic, wind, and earthquake during their life time. Continuous exposure to such severe loadings may lead to structural damage requiring costly repair/retrofit and even may result in an unexpected disaster, which emphasizes the importance of assessing the current condition of bridges. From the last decade, FE model updating techniques based on the bridge dynamic characteristics are emerged to evaluate the current condition of bridges quantitatively. Most of the model updating techniques basically utilize an optimization process with an objective function built up by the residuals between the natural… More >

Lu Wang, Guangyan Liu, Yanan Yi, Shaopeng Ma^*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.2, pp. 31-31, 2019, DOI:10.32604/icces.2019.04974

Abstract Nuclear graphite is a key material in high temperature gas-cooled reactors. The evaluation of its damage evolution is of great importance for safety assessment of nuclear graphite structures. However, the damage properties of nuclear graphite are difficult to characterize by the traditional testing approaches, i.e., uniaxial tension and compression tests due to the inconvenience of conducting uniaxial tension/compression tests. In this paper, an inverse method was developed to identify the damage parameters of a nuclear graphite material IG11. The method is based on the non-contact digital image correlation and finite element model updating techniques, and damage-induced nonlinear stress-strain curves for… More >