Nonlinear reduced order modeling of bolted joints

Download
2019
Karapıstık, Gökhan
Most of the structural systems assembled by using bolted joints. Therefore, bolted joint models have a critical importance to estimate the behavior of the overall assembled system. There are several linear bolted joint models, which consist of spring and dashpot elements in literature. While they can estimate the resonant frequency of the overall system with a sufficient accuracy, linear bolted joint models are inadequate for approximating the damping, which arises from the friction in the contact interface of assembled system. On the other hand, there are examples of nonlinear bolted joint models, which utilize 3D contact models to account for the frictional damping behavior in the literature. However, modeling the structures with many bolted joints by using high fidelity 3D contact models is very time consuming. Therefore, reduced order bolted joint models with sufficient accuracy are in need. In this thesis, a method for modeling bolted joints in frequency domain is introduced. The joint model consists of microslip friction elements each one of which is constructed by several dry friction elements in parallel and located at the contact interface.

Suggestions

Reduced Order Modeling of Bolted Joints in Frequency Domain
Karapıstık, Gökhan; Ciğeroğlu, Ender (2019-01-31)
Most of the structural systems assembled by using bolted joints. Therefore, bolted joint models have a critical importance to estimate the behavior of the overall assembled system. There are several linear bolted joint models which consist of spring and dashpot elements in literature. While they can estimate the resonant frequency of the overall system with a sufficient accuracy, linear bolted joint models are inadequate for approximating the damping which arises from the friction in the contact interface o...
Dynamic modeling of structural joints
Tol, Şerife; Özgüven, Hasan Nevzat; Department of Mechanical Engineering (2012)
Complex systems composed of many substructures include various structural joints connecting the substructures together. These mechanical connections play a significant role in predicting the dynamic characteristics of the assembled systems accurately. Therefore, equivalent dynamic models of joints that consist of stiffness and damping elements should be developed and the joint parameters should be determined for an accurate vibration analysis. Since it is difficult to estimate joint parameters accurately by...
Damage detection in structures using vibration measurements
Aydoğan, Mustafa Özgür; Özgüven, Hasan Nevzat; Department of Mechanical Engineering (2003)
Cracks often exist in structural members that are exposed to repeated loading, which will certainly lower the structural integrity. A crack on a structural member introduces a local flexibility which is a function of the crack depth and location. This may cause nonlinear dynamic response of the structure. In this thesis, a new method is suggested to detect and locate a crack in a structural component. The method is based on the fact that nonlinear response of a structure with a crack will be a function of t...
Quasi-static nonlinear seismic assessment of a fourth century A.D. Roman Aqueduct in Istanbul, Turkey
Gonen, Semih; Pulatsu, Bora; Erdogmus, Ece; Karaesmen, Engin; Karaesmen, Erhan (2021-01-01)
The majority of architectural heritage consists of load-bearing masonry components made up of stone units and relatively weak mortar joints, yielding potential weak planes for masonry structures where tension and shear failures are expected to occur. Advanced nonlinear analyses are required to simulate these phenomena and predict the corresponding nonlinear structural behavior of historic masonry constructions. In this context, this paper presents a model of a stone masonry Roman aqueduct (the Valens Aquedu...
Dynamic characterization of bolted joints using FRF decoupling and optimization
Tol, Serife; Özgüven, Hasan Nevzat (2015-03-01)
Mechanical connections play a significant role in predicting dynamic characteristics of assembled structures. Therefore, equivalent dynamic models for joints are needed. Due to the complexity of joints, it is difficult to describe joint dynamics with analytical models. Reliable models are generally obtained using experimental measurements. In this paper an experimental identification method based on FRF decoupling and optimization algorithm is proposed for modeling joints. In the method the FRFs of two subs...
Citation Formats
G. Karapıstık, “Nonlinear reduced order modeling of bolted joints,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Mechanical Engineering., Middle East Technical University, 2019.