Dynamic response of a front end accessory drive system and parameter optimization for vibration reduction via a genetic algorithm

2016 ◽  
Vol 24 (11) ◽  
pp. 2201-2220 ◽  
Author(s):  
Hao Zhu ◽  
Yumei Hu ◽  
WD Zhu
Keyword(s):  
Genetic Algorithm ◽  
Dynamic Response ◽  
Flexural Rigidity ◽  
Optimization Method ◽  
Drive System ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Front End ◽  
Space Technique ◽  
External Forces

A typical engine front end accessory drive system (FEADS) is mathematically modeled through Hamilton’s principle and Newton’s second law. In this model, the belt’s flexural rigidity and pulley’s eccentricity are considered. Eccentricities of the pulleys are introduced into governing motion equations of the belt spans through the boundary conditions and then transformed to external forces acting on the belt spans. Vibration modes and natural frequencies of the FEADS are calculated by the state-space technique of the complex mode theory. Dynamic responses of the FEADS at different rotational rates of the crankshaft are calculated by solving the spatially discretized governing equations obtained by Galerkin method. The modeling and solution methods are formulated and programmed in a general purposed code. The study shows that the typical resonance and beat phenomenon happen in a certain portion of the belt spans at a certain rotational rate by the excitations of the pulley’s eccentricity. According to the modal analysis and dynamic response analysis, an optimization method based on a genetic algorithm is proposed. By comparing the vibration amplitudes of belt spans before and after optimization at different rotational rates, this optimization method is verified to be effective in reducing transverse vibrations of the belt spans.

Dynamic Response of the Steel Bridge Deck Thin Surfacing due to Vehicle Load

2010 ◽  
Vol 148-149 ◽  
pp. 544-547
Author(s):  
Xun Qian Xu ◽  
Ye Yuan Ma ◽  
Guo Qing Wu ◽  
Xiu Mei Gao
Keyword(s):  
Dynamic Response ◽  
Bridge Deck ◽  
Three Dimensional ◽  
Coupled Model ◽  
Interface Layer ◽  
Dynamic Responses ◽  
Steel Bridge ◽  
Vehicle Load ◽  
Moving Vehicles ◽  
Space Technique

Basing on the coupled vibration theory, dynamic behavior of steel bridge deck thin surfacing under rand moving vehicles is studied. A three-dimensional coupled model is carried out for the steel bridges deck thin surfacing and vehicle. A method based on modal superposition and state space technique is developed to solve dynamic response generated by vehicle-surfacing interaction. The dynamic responses of an actual steel bridge deck thin surfacing are studied. The results show that adding epoxy asphalt as a sub coat can improve interface adhesion strength, which would be designed as the interface layer of steel deck thin surfacing.

Dynamic Response Analysis of Bridge Pier Subject to Earthquake and Ice Loads

2011 ◽  
Vol 250-253 ◽  
pp. 2211-2215
Author(s):  
Fu Qiang Qi
Keyword(s):  
Dynamic Response ◽  
Dynamic Equilibrium ◽  
Work Conditions ◽  
Bridge Pier ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Analysis Method ◽  
Equilibrium Equations ◽  
Different Types ◽  
Ice Loads

In order to discuss the effect of earthquake and dynamic ice loads to a bridge pier, this paper considered the effect of added mass of dynamic water, and it deduced the dynamic equilibrium equations for a bridge pier subject to earthquake and dynamic ice loads on the basis of nonlinear Morision equation. Using numerical analysis method, it discussed the dynamic response of a bridge pier subject to different types of earthquake loads, forced ice loads, and both earthquake and forced ice loads. Through comparing the pier responses in different work conditions, it discovered that the dynamic responses of the bridge pier subject to forced dynamic ice loads rise and fall severely at the time of ice buckling broken periodic change. The coupling effects of forced dynamic ice loads and earthquake especially near-fault earthquake enhance the dynamic response of bridge pier significantly.

scholarly journals Numerical earthquake response analysis of the Liyutan earth dam in Taiwan

2010 ◽  
Vol 10 (6) ◽  
pp. 1269-1280 ◽  
Author(s):  
Z. Feng ◽  
P. H. Tsai ◽  
J. N. Li
Keyword(s):  
Dynamic Response ◽  
Function Analysis ◽  
Dynamic Responses ◽  
Earth Dam ◽  
Response Analysis ◽  
Vertical Acceleration ◽  
Seepage Analysis ◽  
Time Frequency ◽  
Acceleration Time Histories ◽  
Transfer Function Analysis

Abstract. The dynamic response of the Liyutan earth dam to the 1999 Chi-Chi earthquake (ML=7.3) in Taiwan was numerically analyzed. First, the staged construction of the dam was simulated. Then, seepage analysis, considering a 60-m water level, was performed. After seepage analysis, the initial static stress (prior to dynamic loading) was established in the dam. Both the horizontal and vertical acceleration time histories recorded at the base of the dam were used in the numerical simulations. The dynamic responses of the dam were analyzed for 50 s in the time domain. The simulated results were in agreement with the monitored data. The transfer function analysis and Hilbert-Huang Transform (HHT) were used to compare the results and to perceive the response characteristics of the dam. In particular, the time-frequency-energy plots of the HHT can reveal the timing and time frame of the dominant frequencies of the dynamic response. The influences of the initial shear modulus and uni-axial earthquake loading were also investigated.

Dynamic Response Analysis of Floating Storage Tank System Considering Hydrodynamic and Mechanical Interactions

2018 ◽  
Author(s):  
Ling Wan ◽  
Chi Zhang ◽  
Allan Ross Magee ◽  
Jingzhe Jin ◽  
Mengmeng Han ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Storage Tank ◽  
Hydrodynamic Interaction ◽  
Dynamic Responses ◽  
Hydrodynamic Interactions ◽  
Pile Foundations ◽  
Response Analysis ◽  
Mechanical Interaction ◽  
Tank System ◽  
Coastal Space

For better utilization of ocean and coastal space, hydrocarbon products can be stored in the floating tanks, which can be enclosed by barge system. The barge system can be moored through pile foundations. The tanks are moored through marine fenders connected to barges. In the system, hydrodynamic and mechanical interaction problems are involved. Different scenarios including two barge, three barge and four barge systems are investigated. In addition, one tank plus four barge system are also studied. Hydrodynamic interactions between different bodies are firstly studied to investigate the significance of interaction. Different barge configurations are then considered in terms of mechanical interaction significance. Tank dynamic responses with and without hydrodynamic interaction are evaluated.

scholarly journals Dynamic response analysis of the integrated station-bridge elevated station under the pile-soil interaction

2020 ◽  
Vol 165 ◽  
pp. 04081
Author(s):  
Shuqi Zhang ◽  
Jin Li ◽  
Jingyuan Li ◽  
Jiaolei Zhang
Keyword(s):  
Dynamic Response ◽  
Interaction Model ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Transverse Displacement ◽  
Rigid Foundation ◽  
Base Shear ◽  
Maximum Displacement ◽  
Finite Element Software ◽  
Mechanical Models

In order to study the dynamic response of the integrated station-bridge structure under the pile-soil interaction, a model was established by finite element software for dynamic analysis. According to a practical project, two mechanical models are established: one is the pile-soil interaction model, the other is the rigid foundation model. The dynamic responses of the two models were analyzed respectively, and then the results were compared. The results show that: the structure with pile-soil interaction has a longer period and higher flexibility; Under the action of frequently occurred earthquakes, the maximum displacement of the structure with pile-soil interaction increases and the base shear decreases; Under the action of seldomly occurred earthquakes, the structural displacement and base shear under the pile-soil interaction become larger, and the transverse displacement is more affected than the longitudinal displacement. It is concluded that: the assumption of rigid foundation makes the result more conservative, and the influence of pile-soil interaction cannot be ignored in seismic response analysis.

Dynamic Response Analysis on Flexible Riser With Different Configurations in Deep-Water Based on FEM Simulation

2018 ◽  
Author(s):  
Shuangxi Guo ◽  
Yilun Li ◽  
Min Li ◽  
Weimin Chen ◽  
Yue Kong
Keyword(s):  
Dynamic Response ◽  
Numerical Simulations ◽  
Deep Water ◽  
Dynamic Responses ◽  
Body Motion ◽  
Response Analysis ◽  
Flexible Beam ◽  
Nonlinear Dynamic Model ◽  
Nonlinear Fem ◽  
Structural Length

For case of oil/gas exploitation and mining in deep water, the length of riser is pretty large and, consequently, it brings huge challenges in both offshore installation and production operations and results in significant cost elevation due to the factors such as extreme tension loads induced from riser suspended self-weight and large structural flexibility. Therefore, there are several alternative riser configurations, e.g. lazy wave, hybrid tower and lazy-wave riser beside free hanging catenary, which have been proposed. In this paper, the dynamic characteristics and responses of several risers with typical configurations are considered and compared with each other based on our numerical simulations. Firstly, the nonlinear dynamic model of the riser systems are developed based on our 3d dynamic riser equations along with the modified FEM simulations. Then the dynamic response is analyzed based on our 3d curved flexible beam approach where the structural curvature changes with its spatial position and time in terms of vector equations. Compared with the linear approach, the nonlinear FEM method is used so as to consider large displacement/deformation, configuration geometry and structural stiffness changing with body motion. Moreover, the hydrodynamic force is considered as being related to body motion too. Based on the FEM numerical simulations, the influences of the amplitude/frequency of the top vessel motion along with the buoyancy modules/tower distribution along structural length on riser’s dynamic responses, in terms of the temporal-spatial evolution of displacement, curvature/bending stress and dynamic tension, are studied for different riser’s configurations. Our results show that the dynamic responses, particularly the maximum top tension, of different riser systems significantly change. Among the examined riser configurations, the response of the riser with more buoyancy modules may have lower value, and buoyancy distribution along structural length can influence the top tension and curvature.

Dynamic Response Analysis of a Floating Offshore Wind Turbine During Severe Typhoon Event

2013 ◽  
Author(s):  
Tomoaki Utsunomiya ◽  
Iku Sato ◽  
Shigeo Yoshida ◽  
Hiroshi Ookubo ◽  
Shigesuke Ishida
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Dynamic Responses ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Dynamic Response Analysis ◽  
Floating Offshore Wind Turbine ◽  
Demonstration Experiment ◽  
Typhoon Event

In this paper, dynamic response analysis of a Floating Offshore Wind Turbine (FOWT) with Spar-type floating foundation is presented. The FOWT mounts a 100kW down-wind turbine, and is grid-connected. It was launched at sea on 9th June 2012, and moored on 11th for the purpose of the demonstration experiment. During the experiment, the FOWT was attacked by severe typhoon events twice. Among them, Sanba (international designation: 1216) was the strongest tropical cyclone worldwide in 2012. The central atmospheric pressure was 940 hPa when it was close to the FOWT, and the maximum significant wave height of 9.5m was recorded at the site. In this paper, the dynamic responses of the platform motion, the stresses at the tower sections and the chain tensions during the typhoon event, Sanba (1216), have been analyzed, and compared with the measured data. Through the comparison, validation of the numerical simulation tool (Adams with SparDyn developed by the authors) has been made.

Dynamic responses of an engine front-end accessory belt drive system with pulley eccentricities via two spatial discretization methods

2017 ◽  
Vol 232 (4) ◽  
pp. 482-498 ◽  
Author(s):  
Hao Zhu ◽  
Yumei Hu ◽  
Weidong Zhu ◽  
Haiqiang Long
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Bending Stiffness ◽  
Drive System ◽  
Dynamic Responses ◽  
Belt Drive ◽  
Discretization Method ◽  
Spatial Discretization ◽  
Galerkin Discretization ◽  
Front End

In this study, a generic mathematical model for calculating the natural frequencies and the dynamic responses of a typical front-end accessory drive system with any number of pulleys and arbitrary configurations of the tensioner and pulleys is established. The belt bending stiffness and the pulley eccentricities are considered in this model, and their influences on the natural frequency and the dynamic responses of the front-end accessory drive system are examined. A generic spatial discretization method and a Galerkin discretization method, which uses Lagrange multipliers to enhance the boundary conditions, are presented to discretize the continuous belt spans and to transform the governing partial differential equations into ordinary differential equations. The accuracies of the generic spatial discretization method and the Galerkin discretization method are validated by modal tests, and the advantages of the generic spatial discretization method with respect to the efficiency and the convenience of implementation are assessed by comparing the generic spatial discretization method with the Galerkin discretization method and the two-layer iteration approach. The dynamic responses of the typical front-end accessory drive system at different operational velocities are calculated from the governing ordinary differential equations derived from these two methods. It is shown that large vibration amplitudes occur in certain belt spans owing to the resonance conditions or the beat phenomena in certain operational conditions and that the belt bending stiffness has a negligible influence on the vibrations of the belt drive system because its value is small.

Dynamic Response and Reliability of Six-Leg Jack-Up Type Wind Turbine Installation Vessel

2017 ◽  
Vol 17 (03) ◽  
pp. 1750037 ◽  
Author(s):  
Sanghwan Heo ◽  
Weoncheol Koo ◽  
Min-Su Park
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Time Integration ◽  
Numerical Procedure ◽  
Slender Body ◽  
Dynamic Responses ◽  
Response Analysis ◽  
Natural Period ◽  
Jack Up ◽  
Turbine Installation

A fast, reliable and optimized numerical procedure of the hydrodynamic response analysis of a slender-body structure is presented. With this method, the dynamic response and reliability of a six-leg jack-up-type wind turbine installation vessel under various environmental conditions is analyzed. The modified Morison equation is used to calculate the wave and wind-driven current excitation forces on the slender-body members. The Det Norske Veritas (DNV) rule-based formula is used to calculate the wind loads acting on the superstructure of the jack-up leg. From the modal analysis, the natural period and standardized displacement of the structure are determined. The Newmark-beta time-integration method is used to solve the equation of motion generating the time-varying dynamic responses of the structure. A parametric study is carried out for various current velocities and wind speeds. In addition, a reliability analysis is conducted to predict the effects of uncertainty of the wave period and wave height on the safety of structural design, using the reliability index to indicate the reliability of the dynamic response on the critical structural members.

scholarly journals Dynamic Response Analysis of a Semi-Submersible Floating Wind Turbine in Combined Wave and Current Conditions Using Advanced Hydrodynamic Models

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5820 ◽  
Author(s):  
Takeshi Ishihara ◽  
Yuliang Liu
Keyword(s):  
Dynamic Response ◽  
Wind Turbine ◽  
Wave Spectrum ◽  
Full Scale ◽  
Dynamic Responses ◽  
Offshore Wind Turbine ◽  
Response Analysis ◽  
Water Tank ◽  
Hydrodynamic Models ◽  
Wide Range

In this study, advanced hydrodynamic models are proposed to predict dynamic response of a floating offshore wind turbine (FOWT) in combined wave and current conditions and validated by laboratory and full-scale semi-submersible platforms. Firstly, hydrodynamic coefficient models are introduced to evaluate the added mass and drag coefficients in a wide range of Reynolds numbers. An advanced hydrodynamic model is then proposed to calculate the drag force of cylinder in combined wave and current conditions. The proposed model is validated by the water tank tests in the current-only, wave-only and current-wave conditions and is used to investigate the effect of current on the dynamic response of FOWT. Finally, the full-scale semi-submersible platform used in the Fukushima demonstration project is investigated. It is found that the predicted dynamic responses of platform by the proposed hydrodynamic models are improved by the directional spreading function of the sea wave spectrum and show favorable agreement with the field measurement.

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