Dynamic Response Analysis of Ship Hull Structures

2000 ◽  
Vol 37 (03) ◽  
pp. 117-128
Author(s):  
T. V. S. R. Appa Rao ◽  
Nagesh R. Iyer ◽  
J. Rajasankar ◽  
G. S. Palani
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Element Model ◽  
Ship Hull ◽  
Response Analysis ◽  
Dynamic Response Analysis ◽  
Hull Structure ◽  
The Finite Element Model

Finite-element modeling and use of appropriate analytical techniques play a significant role in producing a reliable and economic design for ship hull structures subjected to dynamic loading. The paper presents investigations carried out for the dynamic response analysis of ship hull structures using the finite-element method. A simple and efficient interactive graphical preprocessing technique based on the "keynode" concept and assembly-line procedure is used to develop the finite-element model of the hull structure. The technique makes use of the body plan of a ship hull to build the finite-element model through an interactive session. Stiffened plate/shell finite elements suitable to model the hull structure are formulated and used to model the structure. The finite elements take into account arbitrary placement of stiffeners in an element without increasing the number of degrees-of-freedom of the element. A three-dimensional finite-element model and a procedure based on the Bubnov-Galerkin residual approach are employed to evaluate the effects of interaction between the ship hull and water. Mode superposition technique is used to conduct the dynamic response analysis. The efficiency of the finite elements and the procedures is demonstrated through dynamic analysis of a submerged cantilever plate and a barge when both are subjected to sinusoidal forces. The dynamic responses exhibit expected behavior of the structure and a comparison with the results available in the literature indicate superior performance of the finite element and methodologies developed. Thus, the finite-element models and the procedures are found to be efficient and hence suitable for the dynamic analysis of similar structures.

Instantaneous Dynamic Analysis of the New Stirring Kneader Shaft

2011 ◽  
Vol 221 ◽  
pp. 472-477
Author(s):  
Zhi Min Fan ◽  
Guang Ting Zhou ◽  
Jian Ping Liu
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Dynamic Analysis ◽  
Structural Parameters ◽  
Element Model ◽  
Fatigue Analysis ◽  
Exciting Force ◽  
The Finite Element Model

The finite element model of the stirring kneader shaft was built by PRO/E software, which was inserted into ANSYS. Next, the instantaneous dynamic analysis of the new stirring kneader shaft was carried out. The instantaneous dynamic response of stirring shaft about the exciting force of fluid was obtained, which was to optimize the structural parameters of the stirring shaft. The foundation for the next fatigue analysis was laid based on the instantaneous dynamic response; the fatigue life of stirring kneader shaft can be predicted.

Analysis of Dynamic Characteristic of Numerical Remanufacture Machine's Feeding System

2010 ◽  
Vol 156-157 ◽  
pp. 1360-1365
Author(s):  
Qiu Lin Pu ◽  
Xiao Diao Huang ◽  
Wen Zheng Ding
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Operating Conditions ◽  
Ball Screw ◽  
Response Analysis ◽  
Feeding System ◽  
Nature Frequency ◽  
Grinding Machine ◽  
The Finite Element Model

In this paper,the ball screw feeding system’s dynamic characteristics of a numerical remanufacture grinding machine is analyzed using the FEM. Discusses the modeling method of ball screw system into the finite element model and established the combination of finite element model. Through the modal analysis and the harmonious response analysis, the nature frequency and vibration mode of the feeding system and typical operating conditions of excitation in the harmonic responsehave have been gotten,thus the dependable basis for the construction’s optimization and dynamic function’s increasing of the feeding system is provided, ensure the numerical remanufacture will be success.

Simulating the Mechanical Properties of a Yarn Based on the Properties and Arrangement of its Fibers Part I: The Finite Element Model

1997 ◽  
Vol 67 (4) ◽  
pp. 263-268 ◽  
Author(s):  
Lieva Van Langenhove
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Theoretical Model ◽  
Finite Elements ◽  
Finite Element Model ◽  
Tensile Strain ◽  
Virtual Work ◽  
Element Model ◽  
Dynamic Relaxation ◽  
The Finite Element Model

A theoretical model is established to predict stress-strain and torque-tensile strain curves of a yarn. The yarn is described by its properties and the arrangement of its fibers, which have a finite length. The yarn is transformed into finite elements. Equilibrium is expressed by virtual work, and is calculated iteratively using the dynamic relaxation technique. The principles of the model, its potential, limitations, and possible improvements are discussed.

Dynamic Response Analysis of Stop Log Gates in Power Station’s Running Process

2014 ◽  
Vol 1070-1072 ◽  
pp. 1906-1910
Author(s):  
Min Zhe Zhou ◽  
Tong Chun Li ◽  
Yuan Ding ◽  
Yun Guo
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Pressure Distribution ◽  
Water Depth ◽  
Element Model ◽  
Response Analysis ◽  
Upstream Pressure ◽  
The Difference ◽  
Horizontal Displacements

In this paper, a 3-D finite element model was established for stop log gates. It is used for researching its force situation in process of power on and power off. The vertical pressure distribution around stop log gates shows that with water depth increasing, the difference of downstream pressure and upstream pressure of gates become more obvious. Between power on and power off processes, the stop log gates’ pressure differences and horizontal displacements are opposite.

Dynamic Response Analysis of Working Device of Hydraulic Excavator under Working Impact Loading

2009 ◽  
Vol 16-19 ◽  
pp. 39-43
Author(s):  
Li Xin Guo ◽  
Hua Long Xie ◽  
Shu Wen Zhou ◽  
Jin Li Li ◽  
Zhao Wen Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Element Model ◽  
Structure Design ◽  
Resistance Force ◽  
Response Analysis ◽  
Hydraulic Excavator ◽  
Dynamic Response Analysis ◽  
Working Device ◽  
Resistance Forces

A there-dimensional finite element model of the working device of a single backhoe-bucket hydraulic excavator was developed to analyze and evaluate the rationality of structure design of the working device in this study. By finite element modal analysis, the resonant frequencies and vibration modes of the working device system were obtained. By dynamic response analysis, the changing trends of stress and strain of the device were obtained. In addition, the influence of different excavating resistance forces to the working device on dynamic response of the device system was compared for large and small resistance forces at the beginning excavation moment. The results show that a large resistance force at the initial excavating moment may result in the device vibrating with large vibration amplitude at the beginning excavation moment. These results might provide useful reference on design improvement of the excavator working device.

Study on Random Vibration Response Analysis for the Sphere Cylinder Assembly in Aerospace Vehicle

2014 ◽  
Vol 680 ◽  
pp. 258-262
Author(s):  
De Lin Sun ◽  
Zhe Zhao ◽  
Kun He ◽  
Ri Dong Liao
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basic Principle ◽  
Random Vibration ◽  
Structural Strength ◽  
Element Model ◽  
Vibration Response ◽  
Response Analysis ◽  
Vibration Load ◽  
The Finite Element Model

To assess the structural strength of spherical cylinder, the finite element model was constructed by the NX NASTRAN software. Firstly,the basic principle of random vibration response analysis was introduced, then the random vibration response analysis of the cylinder assembly was analyzed. The simulation result shows that the stress of the joint between spherical cylinder clamp and the base is larger than other areas in conditions of a given random vibration load. The spherical cylinder structure is safe and that the maximum RMS stress is about 20 MPa.

The Numerical Simulation Research of the Dynamic Response of RC Frame Structure under the Internal Explosion

2014 ◽  
Vol 1065-1069 ◽  
pp. 2090-2094
Author(s):  
Bin Jia ◽  
Xiao Wei Zhu ◽  
Zhu Wen ◽  
Qi Jiang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Dynamic Response ◽  
Finite Element Model ◽  
Element Model ◽  
Frame Structure ◽  
Rc Frame ◽  
Simulation Research ◽  
Rc Frame Structure ◽  
The Finite Element Model

The finite element model was established in this paper to study the process of dynamic response of RC frame structure under internal explosive loading. The burst point in the model was located in the center of the frame structure .The article analyzed the process of the dynamic response of the frame structure in the explosive environment and the result of the numerical simulation accorded well with the test. The result showed that the finite element model was feasible as well as providesed reference to the design and protection for the building structure.

Thermal Response Analysis of Large Aperture Optical Components

2008 ◽  
Author(s):  
Yi Zhou ◽  
Dong-hui Lin ◽  
Hai Zhou ◽  
Jun-wei Zhang ◽  
Shi-long Wang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Thermal Response ◽  
Element Model ◽  
Optical Component ◽  
Response Analysis ◽  
Optical Components ◽  
Large Aperture ◽  
Confinement Fusion ◽  
The Finite Element Model

This paper analyze the deformation of large aperture optical components under the thermal load based on the finite element model developed using the ANSYS software, which are used for inertia confinement fusion (ICF) experiments. High precision sensors are used to measure the temperature around the optical components in the target building and to form the temperature changing curve. The biggest temperature change is 0.3°C during 2 hours based on the measurement. The change is then loaded on the finite element model of a typical large aperture optical component to get the deformation of the optical component. The results indicate that the deformation of the optical component can satisfy the stability requirement in the current environment. Meanwhile, the deformation of the optical component is calculated for different temperature changes and the results show that the deformation of the optical component have a direct relationship with the change of temperature.

Load Generation for Structural Strength Analysis of Large Containerships

2008 ◽  
Author(s):  
Jo¨rg Ro¨rup ◽  
Thomas E. Schellin ◽  
Helge Rathje
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Structural Integrity ◽  
Element Model ◽  
Strength Analysis ◽  
Rule Based ◽  
Hull Structure ◽  
Global Strength ◽  
The Finite Element Model ◽  
Load Generation

Many modern ships, particularly large containerships, are characterized by extreme bow flare, large stern overhang, and low torsional rigidity due to an open deck structural configuration. Software package GL ShipLoad was developed as an aid to assess the structural integrity of such ships. This software tool became the standard method to generate rule based loads for a global strength finite element analysis of sea going displacement ships. It efficiently generates loads based on first principles. A graphical user interface facilitates the convenient application of ship and cargo masses to the finite element model and aids in the selection of relevant design wave situations. User defined selection criteria, such as maximum values of rule based bending moments, shear forces, or torsional moments, specify which waves have to be chosen for the global strength analysis. This approach yields a reduced number of balanced load cases that are sufficient to dimension the hull structure. To adequately simulate roll motion, additional roll angles are analyzed that simulate realistic distributions of torsional moments over the ship length. A strength analysis of a typical post-panamax containership demonstrated the load generation procedure. First, efficiently modeled mass items were grouped into reusable assembled masses for the ship at hydrostatic equilibrium. Second, regular design wave scenarios were estimated, and hydrodynamic pressures for a large number of regular waves were computed. Third, a reduced number of relevant wave situations were automatically selected, and balanced hydrostatic, hydrodynamic, and inertia loads were applied to the finite element model. Enforced roll angles were found to contribute significantly to the initial torsional moment in the fore holds. Finally, based on a locally refined FE submodel of the hatch corners in way of the ship’s fore hold, a fatigue analysis was performed to assess effects of critical loading under enforced roll angles.

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