Dynamic Response Analysis of Beam Mode Vibration of Piping System due to Turbulent Flow Around Bend

2019 ◽  
Author(s):  
Shunji Kataoka ◽  
Kota Matsuura ◽  
Shaoxiang Qian
Keyword(s):  
Structural Analysis ◽  
Pressure Fluctuations ◽  
Assessment Method ◽  
Design Stage ◽  
Response Analysis ◽  
Piping System ◽  
Fluid Turbulence ◽  
Mode Vibration ◽  
Dynamic Structural Analysis ◽  
Beam Mode

Abstract Prevention of piping vibrations during design stage has attracted attention recent years. Though the piping vibration occurs due to various mechanisms, the vibration due to fluid turbulence is one of a major topic discussed. The pressure fluctuation due to fluid turbulence occurs around flow discontinuities such as branches, elbows, flow expansions and valves, and the fluctuation can cause the piping vibration and both shell mode and beam mode vibration can occur. Guideline published by Energy Institute UK[1] (EI-AVIFF) shows a method to check the possibility of piping vibration due to flow induced turbulence and it gives some information on recommended piping span. The method is quite useful for screening purpose to select the piping system with potential vibration risks. However, it is known that the guideline is based on very conservative assumptions, as 90-degree miter bend, and it results in overdesign of piping systems, so more detailed vibration assessment approach succeeding the screening is demanded. In this paper, the method of detailed beam-mode piping vibration assessment using finite element dynamic structural analysis and Large Eddy Simulation (LES) based CFD are discussed. As an example, LES based CFD analyses were conducted on 90 degrees single miter bend, long and short elbow. The resultant pressure fluctuations are compared to past published report and good agreement was confirmed. The CFD results were reorganized and piping dynamic analysis were conducted. Based on these analysis results, the detailed piping vibration risk assessment method using CFD and dynamic structural analysis are proposed.

Dynamic structural analysis of connecting rod through adaptive mesh refinement for different materials

2018 ◽  
Vol 50 (04) ◽  
pp. 561-570
Author(s):  
I. A. QAZI ◽  
A. F. ABBASI ◽  
M. S. JAMALI ◽  
INTIZAR INTIZAR ◽  
A. TUNIO ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Adaptive Mesh Refinement ◽  
Mesh Refinement ◽  
Adaptive Mesh ◽  
Connecting Rod ◽  
Dynamic Structural Analysis

Research on Characteristics of Fluid Exciting Force of Reactor Internals

2021 ◽  
Author(s):  
Zhipeng Feng ◽  
Liwen Deng ◽  
Xuan Huang ◽  
Pingchuan Shen ◽  
Shuai Liu ◽  
...  
Keyword(s):  
Pressure Fluctuation ◽  
Nuclear Reactor ◽  
Wide Band ◽  
Exciting Force ◽  
Design Stage ◽  
Response Analysis ◽  
Flow Induced Vibration ◽  
Analysis And Evaluation ◽  
Safety And Reliability ◽  
Force Characteristics

Abstract Flow-induced vibration is an important issue related to the safety and reliability of nuclear reactor, which need to be analyzed and evaluated in the design stage. In order to obtain the input loads and key parameters used in the calculation of flow-induced vibration of reactor vessel internals (RVIs) that need to satisfy the engineering requirements. The typical RVIs are selected as the research object, and the fluid exciting force characteristics are studied based on the computational fluid dynamics methods. The results show that the fluid exciting force acting on the RVIs is a wide-band stochastic process. For upper internal, the largest pressure fluctuation occurs at the guide tubes and support columns located near the outlet. Therefore, it is necessary to pay more attention to these guide tubes and support columns in response analysis. As for core barrel, the root mean square value of the pressure fluctuation changes drastically at the inlet and outlet location. For lower internal, the lower flow field of RVIs is relatively disordered, and its pressure fluctuation possesses irregular characteristics. Each component of lower internal need to be considered in analysis and evaluation.

Frequency Response Analysis (FRA) Fault Diagram Assessment Method

2021 ◽  
pp. 1-1
Author(s):  
Asier B. Mugarra ◽  
Hernan Mayora ◽  
Jose Manuel Guerrero ◽  
Carlos Antonio Platero
Keyword(s):  
Frequency Response ◽  
Assessment Method ◽  
Response Analysis ◽  
Frequency Response Analysis

Performance-Based Seismic Design

2012 ◽  
pp. 23-50 ◽  
Author(s):  
Oscar Möller ◽  
Marcelo Rubinstein ◽  
Fabián Savino ◽  
Ricardo O. Foschi
Keyword(s):  
Neural Networks ◽  
Structural Analysis ◽  
Earthquake Engineering ◽  
Optimization Algorithm ◽  
Limit State ◽  
Design Parameters ◽  
Total Cost ◽  
Operational Life ◽  
Performance Based Seismic Design ◽  
Dynamic Structural Analysis

An approach is presented to structural optimization for performance-based design in earthquake engineering. The objective is the minimization of the total cost, including repairing damage produced by future earthquakes, and satisfying minimum target reliabilities in three performance levels (operational, life safety, and collapse). The different aspects of the method are considered: a nonlinear dynamic structural analysis to obtain responses for a set of earthquake records, representing these responses with neural networks, formulating limit-state functions in terms of deformations and damage, calculating achieved reliabilities to verify constraint violations, and the development of a gradient-free optimization algorithm. Two examples illustrate the methodology: 1) a reinforced concrete portal for which the design parameters are member dimensions and steel reinforcement ratios, and 2) optimization of the mass at the cap of a pile, to meet target reliabilities for two levels of cap displacement. The objective of this latter example is to illustrate model effects on optimization, using two different hysteresis approaches.

scholarly journals Frequency Domain Response of Jacket Platforms under Random Wave Loads

2019 ◽  
Vol 7 (10) ◽  
pp. 328
Author(s):  
Xiaoshuang Han ◽  
Weiliang Qiao ◽  
Bo Zhou
Keyword(s):  
Design Stage ◽  
Response Analysis ◽  
Random Wave ◽  
Preliminary Design ◽  
Wave Loads ◽  
Spectral Densities ◽  
Spectral Moments ◽  
Jacket Platform ◽  
Power Spectral ◽  
Power Spectral Densities

This article presents a procedure that simplifies an offshore jacket platform as a non-uniform cantilever beam subjected to an axial force. A Ritz method combined with a pseudo-excitation method is then used to analyze the responses of the jacket platform under random wave loads with the associated power spectral densities, variances and higher spectral moments. The theoretical basis and pertinent governing equations are derived. The proposed procedure not only eases the process of determining the pseudo wave loads, but also requires only the rudimentary structural details that are typically available at the preliminary design stage. Additionally, the merit of the proposed procedure is that the process does not require one to compute the normal modes, which saves time and is particularly convenient for the dynamic-response analysis of a complex structure (such as an offshore platform). An illustrative example based on a three-deck jacket platform is presented to demonstrate the procedure used to obtain the power spectral densities, variances and second spectral moments of jacket-top displacement and the bending moment of the jacket at the mud line. The results obtained are compared with those obtained using a Finite Element Mothed (FEM) model. Based on the findings of the study and good agreement shown in the comparison of results, it is concluded that the proposed method is effective, simple and convenient, and can be a useful tool for the preliminary design analysis of offshore platforms.

Sign in / Sign up

Export Citation Format

Share Document