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.

Design and Strength Analysis of the Wheelchair Switching Mechanism

2014 ◽  
Vol 494-495 ◽  
pp. 337-340 ◽  
Author(s):  
Yu Wen Li ◽  
Jian Kang Wei ◽  
Jin Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Theoretical Basis ◽  
Element Model ◽  
Strength Analysis ◽  
Electric Wheelchair ◽  
Switching Mechanism ◽  
Design Proposal ◽  
The Finite Element Model ◽  
Climbing Stairs

Based on studying the existing electric wheelchairs for disabled are not well adapted to a variety of road conditions, broken through the structure of traditional wheelchairs, a design proposal that can make electric wheelchair achieve the function of climbing stairs and walking was putted forward and a novel mechanism was designed. The mechanism can make the crawler chassis and the wheels of wheelchair switch when needed, and make the wheelchair travel freely and flexible on the ground or on the stairs. The finite element model of the mechanism was built, and the strength analysis was carried out. The strength analysis provide the theoretical basis for the prototype manufacture.

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.

Static Strength and Fatigue Analysis of the Automobile Sub-Frame by FEA Simulation Method and Fatigue Test

2011 ◽  
Vol 179-180 ◽  
pp. 186-191 ◽  
Author(s):  
Mao Tao Zhu ◽  
Zhong Wang ◽  
Wei Wei Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Finite Element Model ◽  
Element Model ◽  
Static Strength ◽  
Strength Analysis ◽  
Element Analysis ◽  
Fea Simulation ◽  
The Finite Element Model

Applying the method of finite element analysis, the finite element model of sub-frame of an automobile was built. With the aid of MSC software, longitudinal force operating mode which was pre-verified to be the most critical mode, was chosen for the static strength analysis and fatigue life simulation analysis of the sub-frame. Then the stress and fatigue life nephograms of the sub-frame were gotten. Comparison between finite element analysis and experiment result indicated that the finite element model can practically and properly reflect the real stress distribution of the sub-frame. Finally, based on this finite element model, some structure optimizations were done. After structure optimizations, the stress level was obviously improved. This method of FEA simulation together with experimental verification, significantly reduces the development cycle of new products, and is of important value in product design and quality improvement.

scholarly journals Sensitivity Analysis of the Influence of Structural Parameters on Dynamic Behaviour of Highly Redundant Cable-Stayed Bridges

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Structural Parameters ◽  
Element Model ◽  
Structural Behavior ◽  
Model Tuning ◽  
The Finite Element Model ◽  
Cable Stayed Bridges

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.

Biodynamics of Human Thorax With Body Armors Subject to Bullet Impact

2001 ◽  
Author(s):  
Y. W. Kwon ◽  
J. A. Lobuono
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Body Armor ◽  
Projectile Impact ◽  
Human Thorax ◽  
Trachea And Bronchi ◽  
Armor System ◽  
The Finite Element Model

Abstract The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.

Dynamic Analysis of a Turbocharger Centrifugal Compressor Impeller

1991 ◽  
Author(s):  
V. Ramamurti ◽  
D. A. Subramani ◽  
K. Sridhara
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Centrifugal Compressor ◽  
Element Model ◽  
Simplified Model ◽  
Cyclic Symmetry ◽  
Compressor Impeller ◽  
Cyclic Symmetric ◽  
The Finite Element Model

Abstract Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.

Analysis of Effective Pre-Stress of Continuous Rigid Frame Bridge in Service Based on Inversion Theory

2013 ◽  
Vol 671-674 ◽  
pp. 1012-1015
Author(s):  
Zhao Ning Zhang ◽  
Ke Xing Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Inversion Method ◽  
Vertical Deflection ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Inversion Theory ◽  
Rigid Frame Bridge ◽  
The Finite Element Model

Due to the environment, climate, loads and other factors, the pre-stress applied to the beam is not a constant. It is important for engineers to track the state of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress is analyzed by establishing the finite element model.

scholarly journals Physical Principles of a Piezo Accelerometer Sensitive to a Nearly Constant Signal

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3258 ◽  
Author(s):  
Valery Gupalov ◽  
Alexander Kukaev ◽  
Sergey Shevchenko ◽  
Egor Shalymov ◽  
Vladimir Venediktov
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Frequency Band ◽  
Linear Acceleration ◽  
High Sensitivity ◽  
Element Model ◽  
Wide Frequency Band ◽  
Piezoelectric Accelerometer ◽  
The Finite Element Model ◽  
Physical Principles

The paper considers the construction of a piezoelectric accelerometer capable of measuring constant linear acceleration. A number of designs are proposed that make it possible to achieve high sensitivity with small dimensions and a wide frequency band (from 10−5 Hz). The finite element model of the proposed design was investigated, and its output characteristic and scale factor (36 mV/g) were obtained.

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