tailieunhanh - Determination of the vibration characteristics of bridge in dynamic diagnosis

On the basis of dynamic diagnosis equipment VDIK-1-10 of Russia and finite element method (FEM), the procedures for finding the exciting places and measurement points of vibration are presented. They give us clear information of diagnostic parameters. After data processing we can determine the dynamic characteristics parameters of the bridge. | Vietnam Journal of Mechanics, NCNST of Vietnam T. XX, 1998, No 2 (18 - 26) DETERMINATION OF THE VIBRATION CHARACTERISTICS OF BRIDGE IN DYNAMIC DIAGNOSIS NGUYEN CAO MENH AND PHAM XUAN KHANG Institute of Mechanics ABSTRACT. On the basis of dynamic diagnosis equipment VDIK-1-10 of Russia and finite element method (FEM), the procedures for finding the exciting places and measurement points of vibration are presented. They give us clear information of diagnostic parameters. After data processing we can determine the dynamic characteristics parameters of the bridge. The parameters obtained are used to updating modeling parameters of FEM and therefore the technical state of the bridge could be estimated. An example for inyestigation of prestressed concrete bridge with 33 m span and 10m width is illustrated. 1. Introduction Dynamic diagnosis is the close combination of computation and measurement of dynamic responses of mechanical system such as structures and bridges. After data processing one can get important measurement parameters for updating the modeling parameters of FEM, estimating technical state of the systems and, finally, to detect their damages and defects. It is difficult to reach the latest purpose quickly but the results have to be improved gradually. The dynamical monitoring and diagnosis method for bridges is now developing and improving due to the progress of informatics and measurement equipments [1, 2). New equipment set VDIK-1-10 is made by Russia for this purpose. As we know that the FEM contains a large number of degrees of freedom and only a small number of data can be measured in the limited frequency range. Therefore, there is a need of determination of location of measuring points to assure that the necessary data is collected. On the other hand, it is necessary to find out some main parameters for comparison with computation results. 2. The VDIK-1-10 Equipment . The VDIK-1-10 equipment This equipment is used for dynamic diagnosis of .

• Cơ khí - Chế tạo máy
• Vietnam Journal of Mechanics
• The vibration characteristics of bridge in dynamic diagnosis
• Finite element method
• Determine the dynamic characteristics parameters
• Dynamic diagnosis equipment VDIK 1 10
• Dang Dinh Ang
• Nonlinear analysis and mechanics
• Dynamic problems involving stationary cracks
• The Wiener Hopt technique
• Dual integral equations
• Dual integrals in non linear fracture mechanics
• Non linear fracture mechanics
• Energy release rate
• Discuss the obtained
• The alpha finite element method (αFEM)
• Solid mechanics using triangular and tetrahedral elements
• Suitable computational cost
• NS FEM makes
• The upper bound property
• Non linear constitutive problems in solid mechanics
• Non linear constitutive problems
• Languages Gibian and special operators
• The application FEM
• Betts miller janjic convective parameterization scheme
• H14 31 model to forecast heavy rainfall in Vietnam
• Betts Miller Janjic
• Three rain seasons
• Manufacturing dry mixed cement mortar
• High compressive strength
• High flexural strength
• Low shrinkage and high watertightness for restoration
• Damaged hydraulic structures in Vietnam
• Standard gradient models and crack simulation
• Standard gradient models
• The propagation of cracks
• Damage mechanics and crack simulation
• The interaction between two parametric excitations
• The second and third degrees
• The asymptotic method of nonlinear mechanics
• Dynamic system governed
• Comparison of two hydrological model simulations
• Nam and Xinanjiang for Nong Son catchment
• The Central Vietnam
• The runoff components
• 3 D numerical simulation
• The tidal circulation
• The gulf of Tonkin
• The kinetic energy distribution
• Duality in the analysis of responses to nonlinear systems
• The analysis of responses
• The original nonlinear systems
• The study of nonlinear mechanics
• Aerodynamics of a wing in surface effect ship
• Theory and experiment
• Wing in surface effect ship
• The aerodynamic characteristics
• The Institute of Mechanics
• The error estimate
• The convergence rate for h
• p refinement
• The finite element analysis
• Three dimensional elastostatic mechanics problems
• Some initial experimental results
• Free water layer formation in horizontal pipes
• Water layer formation
• Hanoi Institute of Mechanics
• Bending vibration of beam elements under moving loads
• Considering vehicle braking forces
• Fluctuations of structures
• Beam elements according
• Continuous element for vibration analysis
• Thick shells of revolution
• Continous Element Method
• Finite element solutions
• Natural frequencies and harmonic responses
• Cast3m implementation of the extended finite element method
• The extended finite element method for cohesive crack
• Quasi brittle materia
• The proposed implementation
• The displacement discontinuities
• Buckling analysis of simply supported composite laminates subjected
• In plane compression load
• A novel mesh ffree method
• Alternative numerical technique
• Mesh free method
• A three story building
• Hedge algebras based fuzzy controller
• The structural system
• The El Centro earthquake
• Three story building against earthquake
• Laminar separation phenomenon combining with numerical calculations
• The turbulent separation
• The laminar separation
• Experimental study on mechanical properties
• Three phase polymer composite reinforced
• Glass fibers and titanium oxide particles
• Polymer composite reinforced
• Three phase composite
• Dynamic characteristics of elastically supported beam subjected
• A compressive axial force and a moving load
• The implicit Newmark method
• The Galerkin finite element method
• The axial force
• Eccentrically stiffened functionally graded plates and shallow shells
• Von Karman Donnell sense
• The formulation of governing equations
• The classical shell theory
• Mathematical modelling and control of the evolution
• Dynamic systems interacting with medium
• Mathematical modeling evolutional systems interacting
• Two conjugate mechanical subsystems
• Evaluating structural safety based on fuzzy set theory
• Evaluating structural safety
• The fuzzy reliability
• Simple beam structure