Positioning of bearings for curved continuous spread-box girder bridges

2002 ◽  
Vol 29 (5) ◽  
pp. 641-652 ◽  
Author(s):  
Magdy Samaan ◽  
Khaled Sennah ◽  
John B Kennedy
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Structural Response ◽  
Element Model ◽  
Extensive Study ◽  
Mode Shapes ◽  
Box Girder ◽  
Girder Bridges ◽  
Bridge Superstructure ◽  
Girder Bridge

The type and arrangement of bearings for a bridge superstructure are important considerations in bridge design. For a curved continuous spread-box girder bridge, the support conditions for the bridge superstructure may significantly influence the distribution factors for maximum stresses, reactions, and shear forces as well as the bridge natural frequencies and mode shapes. Current design practices in North America recommend very few guidelines for bearing arrangements and types. This paper describes an extensive study carried out using an experimentally calibrated finite element model, in which curved continuous prototype bridges were analyzed to determine their structural response. Six different types and arrangements of support bearings were studied to determine their effect on the maximum stress and reaction distributions as well as on the natural frequencies of such bridges. The results were used to suggest the most favourable bearing arrangement and type.Key words: bridge bearings, composite, continuous, curved bridges, design, distribution factors, finite element, spread-box.

Study of a curved continuous composite box girder bridge

1993 ◽  
Vol 20 (1) ◽  
pp. 107-119 ◽  
Author(s):  
S. F. Ng ◽  
M. S. Cheung ◽  
H. M. Hachem
Keyword(s):  
Finite Element ◽  
Structural Response ◽  
Shell Element ◽  
Elastic Response ◽  
Box Girder ◽  
Girder Bridges ◽  
Bridge Model ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Critical Sections

To better understand the behaviour of curved box girder bridges in resisting eccentric design truck loads, and the influence of plan curvature on the structural response, a model study was conducted at the University of Ottawa. In this study, the elastic response of a curved composite box girder bridge model was evaluated experimentally and confirmed analytically using the finite element method. Analytical predictions of both vertical displacements and normal stresses at critical sections compared fairly well with those evaluated experimentally. The isoparametric thin shell element employed in the analysis proved to be versatile and provided an accurate representation of the various structural components of a curved box girder bridge. Despite the eccentric nature of the applied OHBDC design truck loads and the bridge plan curvature, it was evident that in resisting the applied live loads, the girders at critical sections share equal proportions of the applied bending moments. Key words: bridge, curved, cellular, composite, eccentric loads, static, linear, experimental, finite element.

A materially nonlinear finite element model for the analysis of curved reinforced concrete box-girder bridges

1993 ◽  
Vol 20 (5) ◽  
pp. 754-759 ◽  
Author(s):  
S. F. Ng ◽  
M. S. Cheung ◽  
J. Q. Zhao
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Model ◽  
Element Model ◽  
Nonlinear Material ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Concrete Box Girder ◽  
Concrete Box Girder Bridges

A layered finite element model with material nonlinearity is developed to trace the nonlinear response of horizontally curved reinforced concrete box-girder bridges. Concrete is treated as an orthotropic nonlinear material and reinforcement is modeled as an elastoplastic strain-hardening material. Due to the fact that the flanges and webs of the structure are much different both in configuration and in the state of stresses, two types of facet shell elements, namely, the triangular generalized conforming element and the rectangular nonconforming element, are adopted to model them separately. A numerical example of a multi-cell box-girder bridge is given and the results are compared favourably with the experimental results previously obtained. Key words: finite element method, curved box-girder bridges, reinforced concrete, nonlinear analysis.

Coupled Bending-Torsion Vibration of Geared Rotors

1995 ◽  
Author(s):  
J. S. Rao ◽  
J. R. Chang ◽  
T. N. Shiau
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Mesh Stiffness ◽  
Present Program ◽  
Gear Mesh ◽  
Pressure Angle ◽  
Torsion Vibration ◽  
Gear Mesh Stiffness

Abstract A general finite element model is presented for determining the coupled bending-torsion natural frequencies and mode shapes of geared rotors. Uncoupled bending and torsion frequencies are obtained for examples available in literature and the present program is verified against these. The effect of the gear box is considered to determine the coupled frequencies. Parameters studied include the pressure angle, gear mesh stiffness, and bearing properties. The gear pressure angle is shown to have no effect on the natural frequencies of rotors supported on isotropic bearing supports. Several case studies with bending-torsion coupling are considered and the results obtained are compared with those available in literature. The results of a general rotor system with 8lodes are also presented.

Calculation of Cross Beam in Continuous Box Girder Bridge Based on Modified Shear Method

2014 ◽  
Vol 578-579 ◽  
pp. 642-647
Author(s):  
Ya Feng Gong ◽  
Xiao Bo Sun ◽  
Huan Li Wang ◽  
Hai Peng Bi
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Traditional Method ◽  
Element Model ◽  
Measured Data ◽  
Box Girder ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Simplified Calculation ◽  
The Finite Element Model

The mechanical properties of cross beam in continuous box girder bridge can be obtained through analyzing the finite element model and measured data of bridge. A new simplified calculation method for cross beam is proposed in this paper, which is called modified shear method. Comparative analysis with traditional method is used to verify its feasibility and practicability.

Support-Condition Analyses of Rotating Beams Under Distributed Imbalance Loading

2011 ◽  
Author(s):  
Kai Jokinen ◽  
Erno Keskinen ◽  
Marko Jorkama ◽  
Wolfgang Seemann
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cross Section ◽  
Cross Sections ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Constant Cross Section ◽  
Support Condition ◽  
Beam Elements

In roll balancing the behaviour of the roll can be studied either experimentally with trial weights or, if the roll dimensions are known, analytically by forming a model of the roll to solve response to imbalance. Essential focus in roll balancing is to find the correct amount and placing for the balancing mass or masses. If this selection is done analytically the roll model used in calculations has significant effect to the balancing result. In this paper three different analytic methods are compared. In first method the mode shapes of the roll are defined piece wisely. The roll is divided in to five parts having different cross sections, two shafts, two roll ends and a shell tube of the roll. Two boundary conditions are found for both supports of the roll and four combining equations are written to the interfaces of different roll parts. Totally 20 equations are established to solve the natural frequencies and to form the mode shapes of the non-uniform roll. In second model the flexibility of shafts and the stiffness of the roll ends are added to the support stiffness as serial springs and the roll is modelled as a one flexibly supported beam having constant cross section. Finally the responses to imbalance of previous models are compared to finite element model using beam elements. Benefits and limitations of each three model are then discussed.

Hydroelastic Modal Analysis of the Perforated Cylindrical Shell in SMART

2011 ◽  
Author(s):  
Youngin Choi ◽  
Seungho Lim ◽  
Kyoung-Su Park ◽  
No-Cheol Park ◽  
Young-Pil Park ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Steam Generators ◽  
Structure Interaction ◽  
The Finite Element Model ◽  
Reactor Internals

The System-integrated Modular Advanced ReacTor (SMART) developed by KAERI includes components like a core, steam generators, coolant pumps, and a pressurizer inside the reactor vessel. Though the integrated structure improves the safety of the reactor, it can be excited by an earthquake and pump pulsations. It is important to identify dynamic characteristics of the reactor internals considering fluid-structure interaction caused by inner coolant for preventing damage from the excitations. Thus, the finite element model is constructed to identify dynamic characteristics and natural frequencies and mode shapes are extracted from this finite element model.

Research on Temperature Effect on the Natural Frequencies of Continuous Beams Based on Stochastic Subspace Identification

2013 ◽  
Vol 706-708 ◽  
pp. 1545-1548
Author(s):  
Yong Chun Cheng ◽  
Yu Ping Shi ◽  
Guo Jin Tan
Keyword(s):  
Dynamic Response ◽  
Temperature Effect ◽  
Natural Frequencies ◽  
Element Model ◽  
Effect Of Temperature ◽  
Subspace Identification ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Stochastic Subspace Identification ◽  
Girder Bridges

Natural frequencies are of great value to bridge structural design, health monitoring and detection. Related research data show that the ambient temperature can affect the natural frequencies of the continuous box-girder bridges. In order to research the effect of temperature on the bridge structure and conclude the influence law, theoretical analysis of temperature effect on the natural frequencies of the continuous box girder bridges is conducted based on the stochastic subspace identification. First, the finite element model of the bridge is built to conduct thermal-structural coupling analysis. Then regard the analysis results as the original state, and exert white noise excitation on the structure to obtain the dynamic response of the structure. And then analyze the dynamic response based on the stochastic subspace identification and calculate the natural frequencies of the bridges under the temperature effect. At last, based on the practical project of one 3-span continuous box-girder bridge, the validity and the reliability of this method is verified.

Natural Vibrations of a Clamped-Clamped Arch With an Open Transverse Crack

1997 ◽  
Vol 119 (2) ◽  
pp. 145-151 ◽  
Author(s):  
M. Krawczuk ◽  
W. Ostachowicz
Keyword(s):  
Finite Element ◽  
Stiffness Matrix ◽  
Edge Crack ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Curved Beam ◽  
Natural Vibrations ◽  
Crack Location ◽  
Cracked Arch

The paper presents a finite element model of the arch with a transverse, one-edge crack. A part of the cracked arch is modelled by a curved beam finite element with the crack. Parts of the arch without the crack are modelled by noncracked curved beam finite elements. The crack occurring in the arch is nonpropagating and open. It is assumed that the crack changes only the stiffness of the arch, whereas the mass is unchanged. The method of the formation of the stiffness matrix of a curved beam finite element with the crack is presented. The effects of the crack location and its length on the changes of the in-plane natural frequencies and mode shapes of the clamped-clamped arch are studied.

Mechanical Analysis of Deck Pavement of Curved Continuous Steel Box Girder

2011 ◽  
Vol 243-249 ◽  
pp. 1941-1946
Author(s):  
Mu Cao ◽  
Guo Fen Li ◽  
Hua Ping Zhu
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Mechanical Analysis ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Steel Box Girder ◽  
Deformation Features ◽  
Stress And Deformation ◽  
Steel Deck

The geometric structure of steel deck plates is complex. So it is difficult to get precise results in the mechanics calculation of deck pavement with traditional methods. This paper adopts the finite element method for the mechanics analysis of the composite guss asphalt surfacing layer of curved steel box girder bridges. By taking the orthotropic steel deck and the pavement as a whole, a reasonable finite element model is established and optimized for the mechanical study of steel deck pavement. This model can be used to study the stress and deformation features of the surfacing layer. According to the common diseases in steel deck pavements and the effect of the overload and the horizontal load in braking to the pavement, this paper puts forward the comprehensive control indicators for pavement failures.

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