TAILIEUCHUNG - Simulation and computation of oscillation and stability of hammer pontoon systems

The ambient exciting loads are regarded as deterministic forces and as stochastic ones. In the latter case, the load is given as spectral density function and it is necessary to calculate probability characteristics of system responses. An example is investigated for illustration. | Vietnam Journal of Mechanics, NCST of Vietnam Vol. 22 , 2000 , No 1 (39 ~ 46) SIMULATION AND COMPUTATION OF OSCILLATION AND STABILITY OF HAMMER-PONTOON SYSTEMS NGUYEN CAO MENH, NGUYEN VAN DAC, VU TAN KHIEM, HOANG NGA Insti"tute of Mechanics, 264 Doi Can, Hanoi ABSTRACT. Hammer pontoon systems are usually used for pile-driving of onshore construction. The systems are constantly acted upon by marine wave, wind and current and have to be fixed by moorings. In this paper, on the basis of software ALASKA the system is simulated as dynamics of multi-body systems . Its natural frequencies and mode shapes are computed in order to avoid resonant phenomena by the change of design parameters . The vibration displacement at any point of the system is calculated for estimation of technical stability of the system. The reaction forces at joints between bodies and its inertial forces are obtained for calculation of system strength of material. The ambient exciting loads are regarded as deterministic forces and as stochastic ones. In the latter case, the load is given as spectral density function and it is necessary to calculate probability characteristics of system responses . An example is investigated for illustration. 1. Introduction A Hammer-pontoon system consists of a pontoon, a hydraulic hammer, a hammer-tower creating the direction for motion of the hammer and some equipment for its working such as pile-driving or changing working places (rig. 1). When the hammer-pontoon system is working, it is fixed by moorings and the hammer-tower is in high position, otherwise the hammer-tower is in lower position. The hammer-pontoon system is usually used for foundation pile-driving of onshore construction. The system is always under action of waves, wind and current. On the basis of software ALASKA (Advanced Lagrangfan Solver in Kinetic Analysis) developed by Institute of Mechatronics, TU-Cheriinitz, Germany, the hammer-pontoon system is modeled as dynamics of multi-body system

• Cơ khí - Chế tạo máy
• Vietnam Journal of Mechanics
• Simulation and computation
• Oscillation and stability
• Hammer pontoon systems
• Investigated for illustration
• 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