Study on the Treatment of Nonlinear Roll Damping in Hydrodynamic Calculation and Structural Analysis

2014 ◽  
Vol 687-691 ◽  
pp. 423-427
Author(s):  
Wei Sun ◽  
Hui Long Ren ◽  
Hui Li
Keyword(s):  
Structural Analysis ◽  
Structural Model ◽  
Wave Loads ◽  
Torsional Moment ◽  
Roll Damping ◽  
Hydrodynamic Calculation ◽  
Moment Distribution ◽  
Calculation Results ◽  
Equivalent Nodal Forces ◽  
Reliable Basis

In order to insure the consistent wave loads in hydrodynamic calculation and structural analysis, the treatment of nonlinear roll damping in roll motion, wave torsional moment and structural analysis are studied. The nonlinear roll damping moment is applied to the structural model by means of the equivalent nodal forces. Taking a supply ship and a FPSO as example, the calculation results show that the problem of torsional moment distribution divergent on the bow and the unbalanced structural model is improved greatly, which would be helpful to provide the reliable basis to design the structures.

scholarly journals Model Analysis and Optimization of BIM Technology in High-rise Shear Wall Residential Structure

2019 ◽  
Vol 267 ◽  
pp. 02001
Author(s):  
Liangli Xiao ◽  
Yan Liu ◽  
Zhuang Du ◽  
Zhao Yang ◽  
Kai Xu
Keyword(s):  
Structural Analysis ◽  
Collaborative Design ◽  
Structural Model ◽  
Structural Information ◽  
Shear Wall ◽  
Structure Design ◽  
Secondary Development ◽  
Optimized Design ◽  
Analysis Model ◽  
High Rise

This study combines specific high-rise shear wall residential projects with the Revit to demonstrate BIM application processes. The use of R-Star CAD may help to realize the link barrier of the building information model and the structural analysis software PKPM. Sequentially, the information supplement of the structural analysis model is completed by extracting the structural information with the Revit secondary development. By the collaborative design platform based on BIM technology, the paper examines the collision check of structural model, conducts collision analysis on other professional models and modifies the design scheme for conflict points. After the statistics of material usage, an optimized design is proposed. The findings of this paper could contribute to provide some reference for the specific application of BIM in structural design and realize the application of BIM technology in the process of building structure design.

Coupling of a Reactor Analysis Code and a Lower Head Thermal Analysis Solver

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Hiroshi Madokoro ◽  
Alexei Miassoedov ◽  
Thomas Schulenberg
Keyword(s):  
Structural Analysis ◽  
Message Passing ◽  
Message Passing Interface ◽  
Severe Accident ◽  
Coupled Analysis ◽  
Accident Analysis ◽  
Analysis Tool ◽  
Lower Head ◽  
Calculation Results ◽  
Reactor Pressure

Due to the recent high interest on in-vessel melt retention (IVR), development of detailed thermal and structural analysis tool, which can be used in a core-melt severe accident, is inevitable. Although RELAP/SCDAPSIM is a reactor analysis code, originally developed for U.S. NRC, which is still widely used for severe accident analysis, the modeling of the lower head is rather simple, considering only a homogeneous pool. PECM/S, a thermal structural analysis solver for the reactor pressure vessel (RPV) lower head, has a capability of predicting molten pool heat transfer as well as detailed mechanical behavior including creep, plasticity, and material damage. The boundary condition, however, needs to be given manually and thus the application of the stand-alone PECM/S to reactor analyses is limited. By coupling these codes, the strength of both codes can be fully utilized. Coupled analysis is realized through a message passing interface, OpenMPI. The validation simulations have been performed using LIVE test series and the calculation results are compared not only with the measured values but also with the results of stand-alone RELAP/SCDAPSIM simulations.

scholarly journals Wave Loads Computation for Offshore Floating Hose Based on Partially Immersed Cylinder Model of Improved Morison Formula

2015 ◽  
Vol 8 (1) ◽  
pp. 130-137 ◽  
Author(s):  
Shi-fu Zhang ◽  
Chang Chen ◽  
Qi-xin Zhang ◽  
Dong-mei Zhang ◽  
Fan Zhang
Keyword(s):  
Mechanical Characteristics ◽  
Water Area ◽  
Wave Loads ◽  
Wave Load ◽  
Mechanic Analysis ◽  
Morison Equation ◽  
Offshore Pipeline ◽  
Cylinder Model ◽  
Calculation Results

Aimed at wave load computation of floating hose, the paper analyzes the morphologic and mechanical characteristics of offshore hose by establishing the partially immersed cylender model, and points out that the results of existing Morison equation to calculate the wave loads of floating hose is not precise enough. Consequently, the improved Morison equation has been put forward based on its principle. Classical series offshore pipeline has been taken as example which applied in the water area of different depth. The wave loads of pipeline by using the improved Morison equation and compared the calculation results with the existing Morison equation. Calculations for wave loads on pipelines in different depth were accomplished and compared by the improved Morison equation and the existing Morison equation. Results show that the improved Morison equation optimizes the accuracy of the computation of wave load on floating hose. Thus it is more suitable for analyzing the effects of wave loads on floating hose and useful for mechanic analysis of offshore pipeline.

scholarly journals A Matrix Formulation for the Moment Distribution Method Applied to Continuous Beams

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Arlindo Pires Lopes ◽  
Adriana Alencar Santos ◽  
Rogério Coelho Lopes
Keyword(s):  
Structural Analysis ◽  
Algebraic Equations ◽  
Displacement Method ◽  
Matrix Formulation ◽  
Distribution Method ◽  
Continuous Beams ◽  
Moment Distribution ◽  
Moment Distribution Method ◽  
Carry Over ◽  
The Moment

The Moment Distribution Method is a quite powerful hand method of structural analysis, in which the solution is obtained iteratively without even formulating the equations for the unknowns. It was formulated by Professor Cross in an era where computer facilities were not available to solve frame problems that normally require the solution of simultaneous algebraic equations. Its relevance today, in the era of personal computers, is in its insight on how a structure reacts to applied loads by rotating its nodes and thus distributing the loads in the form of member-end moments. Such an insight is the foundation of the modern displacement method. This work has a main objective to present an exact solution for the Moment Distribution Method through a matrix formulation using only one equation. The initial moments at the ends of the members and the distribution and carry-over factors are calculated from the elementary procedures of structural analysis. Four continuous beams are investigated to illustrate the applicability and accuracy of the proposed formulation. The use of a matrix formulation yields excellent results when compared with those in the literature or with a commercial structural program.

Structural analysis and 3D geological modelling of the Santerno transect in the Northern Apennines (Italy)

2020 ◽  
Author(s):  
Griso Lorenzo ◽  
Bistacchi Andrea ◽  
Storti Fabrizio
Keyword(s):  
Structural Analysis ◽  
Structural Model ◽  
Regional Scale ◽  
Structural Data ◽  
Northern Apennines ◽  
Geological Mapping ◽  
External Part ◽  
Recent Earthquakes ◽  
3D Framework ◽  
Combine Surface

<p>We present preliminary results of a structural analysis and 3D modelling project carried out along a transect in the Santerno Valley, between Firenzuola (Tuscany) and the outskirts of Imola. The aim of the project is to combine surface geological and structural data (available thanks to the national geological mapping CARG project and original surveys), with the available subsurface data (2D seismics and a few wells), and obtain a comprehensive 3D framework for deformation in this key area of the Northern Apennines. In addition, by combining geodetic, seismicity and interferometric data with the 3D structural model, we are able to obtain a better picture of the active structures in the area.</p><p>Our analysis shows that the studied transect is at the northern periclinal hinge of a regional anticline/window where the Marnoso-Arenacea Formation crops out and is crosscut by several regional-scale thrusts. Subsurface data suggest that these relatively shallow thrusts are rooted at the top of Mesozoic carbonates, that do not crop out in the area. Different balancing algorithms confirm a relevant along-strike variation of slip along these thrusts, that reduce their offset towards the periclinal hinge to the west.</p><p>In the more external part of the transect, towards the lower hills and the plain around Imola, a regional-scale pop-up, evidenced by the late-Messinian unconformity, is the main feature in subsurface datasets. This structure is rooted at the base of Mesozoic carbonates and is characterized by large and continuous ramps that can be considered candidates for recent earthquakes in the area.</p>

Wave Load and Structural Analysis for a Jack-Up Platform in Freak Waves

2007 ◽  
Author(s):  
Ould el Moctar ◽  
Thomas E. Schellin ◽  
Milovan Peric
Keyword(s):  
Structural Model ◽  
Stokes Equations ◽  
Nonlinear Effects ◽  
Breaking Waves ◽  
Wave Loads ◽  
Wave Load ◽  
Two Phase ◽  
Freak Waves ◽  
Highly Nonlinear ◽  
Jack Up

The paper analyzed effects of freak waves on a mobile jack-up drilling platform stationed in exposed waters of the North Sea. Under freak wave conditions, highly nonlinear effects, such as wave run-up on platform legs and impact-related wave loads on the hull, had to be considered. Traditional methods based on the Morison formula needed to be critically examined to accurately predict these loads. Our analysis was based on the use of advanced CFD techniques. The code used here solves the Reynolds-averaged Navier-Stokes equations and relies on the interface-capturing technique of the volume-of-fluid type. It computed the two-phase flow of water and air to describe the physics associated with complex free-surface shapes with breaking waves and air trapping, hydrodynamic phenomena that had to be considered to yield reliable predictions. Lastly, the FEM was used to apply the wave-induced loads onto a comprehensive finite element structural model of the platform, yielding deformations and stresses.

scholarly journals Structure Analysis of Deep Water Spar Platform

2021 ◽  
Author(s):  
Wenjia Hu ◽  
Shisheng Wang
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Deep Water ◽  
Structural Model ◽  
Structural Strength ◽  
Low Frequency ◽  
Global Structure ◽  
Spar Platform ◽  
Dynamic Part ◽  
Wave Parameters

In order to study calculation technology of global structure strength for the deep water typical Spar platform its global structural strength analysis is completed. The dynamic-part and a low frequency-part loads are considered in this analysis. First, according to the 100-year return storm design wave parameters are obtained through search. wave loads with design wave parameters are calculated, and are applied to the structural model built. The stresses of global structure are gotten by finite element structural analysis. Then, low frequency-part loads which include wind, current and mooring forces also are applied to the structural model. The stresses produced by low frequency-part loads are gotten by finite element structural analysis. Finally the stresses produced by dynamic-part and a low frequency-part loads are combined to form total stresses of structure of Spar, and evaluation of structural strength of Spar is made in term of the rule. Analysis method for the structural strength of the deepwater typical Spar platform can be used as reference for relative technical people.

scholarly journals Analysis of the resistance frame of the equipment for opening and compartmentalizing watering furrows, using 3D finite elements

2021 ◽  
Vol 286 ◽  
pp. 03009
Author(s):  
Petru Cardei ◽  
Marius Oprescu ◽  
Nicolae Constantin ◽  
Ștefan-Sorin Biriș ◽  
Sebastian Muraru
Keyword(s):  
Structural Analysis ◽  
Finite Elements ◽  
Stress Field ◽  
Structural Model ◽  
Equivalent Stress ◽  
Relative Displacement ◽  
Cad Cam ◽  
Bearing Structure ◽  
Cam Model

The proposed article sets out the results of the finite element structural analysis for the open and compartmentalised watering furrow equipment (OCWFE). It uses a 3D structural model with 3D finite elements. The analysis set out in the article is made in order to determine the field of relative displacement and equivalent stress in the load-bearing structure of the OCWFE. The structural model is generated in CAD-CAM. For the structural analysis, it is necessary the CAE model, which is obtained from the CAD-CAM model, mainly by eliminating gaps and interferences, but also by the techniques of realizing the contact between the components of the assembly and a careful mashing of the structure. The structural model thus created is supported and loaded in accordance with the experimental results from the literature. The relative displacement field and the equivalent stress field within the resistance frame of the OCWFE is obtained following the linear static analysis. The field of relative displacements is used to assess the effects on the quality of the work performed. The equivalent stress field is used to estimate the safety factor of the structure, by reference to the flow stress of the material from which the structure is built.

scholarly journals On the Completeness of Three-Dimensional Electron Diffraction Data for Structural Analysis of Metal-Organic Frameworks

2021 ◽  
Author(s):  
Meng Ge ◽  
Taimin Yang ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Electron Diffraction ◽  
Structural Model ◽  
Metal Organic Frameworks ◽  
Three Dimensional ◽  
Electron Diffraction Data ◽  
Dimensional Electron ◽  
Data Completeness ◽  
Continuous Rotation ◽  
Metal Organic

<p>Three-dimensional electron diffraction (3DED) has been proven as an effective and accurate method for structure determination of nano-sized crystals. In the past decade, the crystal structures of various new complex metal-organic frameworks (MOFs) have been revealed by 3DED, which has been the key to understand their properties. However, due to the design of transmission electron microscopes (TEMs), one drawback of 3DED experiments is the limited tilt range of goniometer, which often leads to incomplete 3DED data, particularly when the crystal symmetry is low. This drawback can be overcome by high throughput data collection using continuous rotation electron diffraction (cRED), where data from a large number of crystals can be collected and merged. Here, we investigate the effects of improving completeness on structural analysis of MOFs. We use ZIF-EC1, a zeolitic imidazolate framework (ZIF), as an example. ZIF-EC1 crystallizes in a monoclinic system with a plate-like morphology. cRED data of ZIF-EC1 with different completeness and resolution were analyzed. The data completeness increased to 92.0% by merging ten datasets. Although the structures could be solved from individual datasets with a completeness as low as 44.5% and refined to a high precession (better than 0.04 Å), we demonstrate that a high data completeness could improve the structural model, especially on the electrostatic potential map. We further discuss the strategy adopted during data merging. We also show that ZIF-EC1 doped with cobalt can act as an efficient electrocatalyst for oxygen reduction reaction. </p>

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