scholarly journals Nonelinear dynamic analysis of piping system using the pseudo force method

1980 ◽  
Author(s):  
P. Bezler ◽  
S. Prachuktam ◽  
M. Hartzman
Keyword(s):  
Dynamic Analysis ◽  
Piping System ◽  
Force Method

Seismic Analysis of Above Ground Piping in Process Plant

2014 ◽  
Author(s):  
Gaurav P. Bhende
Keyword(s):  
Dynamic Analysis ◽  
Seismic Analysis ◽  
Seismic Effect ◽  
Elastic Behavior ◽  
Piping System ◽  
Process Plant ◽  
Minimum Requirements ◽  
Computer Based ◽  
Design Requirements ◽  
Equivalent Method

The recent natural calamities, especially earthquakes, are making engineering design requirements stringent. The Process Plant Piping is no exception to it. Analyzing the seismic effect by ‘Static Equivalent Method’ is a common practice compared to performing ‘Dynamic Analysis’. This paper starts with the basic reason of earthquake and its effect on the above ground piping system. Further it compares between the results opted based on computer based ‘Spectrum Analysis (Dynamic Analysis) Method’ and ‘Static Equivalent Method’ as per the requirements of ASCE 7. One of the assumptions in Static or Dynamic seismic analysis is — ‘Pipe supports are rigid’. However, in reality the supports, especially structural supports, show elastic behavior based on their material and geometric properties. At the end, this paper compares between the results of seismic analysis performed by considering ‘Supports as rigid’ and ‘Supports as elastic’ and comments on it along with minimum requirements for safe design.

Estimation of Bending Stresses in Piping Systems Subjected to Transient Pressure

2020 ◽  
Author(s):  
Maral Taghva ◽  
Lars Damkilde
Keyword(s):  
Dynamic Analysis ◽  
Static Analysis ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Real Life ◽  
Piping System ◽  
Transient Pressure ◽  
Operational Conditions ◽  
Piping Systems ◽  
Bending Stresses

Abstract Modifications in aged process plants may subject piping systems to fluid transient scenarios, which are not considered in the primary design calculations. Due to lack of strict requirements in ASME B31.3 the effect of this phenomenon is often excluded from piping structural integrity reassessments. Therefore, the consequences, such as severe pipe motion or even rupture failure, are discovered after modifications are completed and the system starts to function under new operational conditions. The motivation for this study emanated from several observations in offshore oil and gas piping systems, yet the results could be utilized in structural integrity assessments of any piping system subjected to pressure waves. This paper describes how to provide an approximate solution to determine maximum bending stresses in piping structures subjected to wave impulse loads without using rigorous approaches to calculate the dynamic response. This paper proposes to consider the effect of load duration in quasi-static analysis to achieve more credible results. The proposed method recommends application of lower dynamic load factors than commonly practiced values advised by design codes, for short duration loads such as shock waves. By presenting a real-life example, the results of improved and commonly practiced quasi-static analysis are compared with the site observations as well as dynamic analysis results. It is illustrated that modified quasi-static solution shows agreement with both dynamic analysis and physical behavior of the system. The contents of this study are particularly useful in structural strength re-assessments where the practicing engineer is interested in an approximated solution indicating if the design criteria is satisfied.

Dynamic analysis of a reciprocrating compressor piping system

2020 ◽  
Vol 20 (2020) ◽  
pp. 297-298
Author(s):  
Claudio de Oliveira Mendonça ◽  
Jorivaldo Medeiros ◽  
Ediberto Bastos Tinoco
Keyword(s):  
Dynamic Analysis ◽  
Piping System

Dynamic Analysis of NPP Piping Systems and Components With Viscoelastic Dampers Subjected to Severe Earthquake Motions

2016 ◽  
Author(s):  
Ichiro Tamura ◽  
Masashi Kuramasu ◽  
Frank Barutzki ◽  
Daniel Fischer ◽  
Victor Kostarev ◽  
...  
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Characteristics ◽  
Seismic Analysis ◽  
Dynamic Properties ◽  
Maxwell Model ◽  
Shaking Table ◽  
Nonlinear Dependence ◽  
Piping System ◽  
Frequency Dependent ◽  
Viscoelastic Dampers

In Shimane nuclear power plant of Chugoku Electric Power Co., a number of safety improvements are planned to be implemented aiming for the highest level of safety in the world to be achieved. One of the new safety measures is the application of viscoelastic dampers for seismic protection of safety related piping system and components. High performance of viscoelastic dampers has been confirmed by direct testing of the piping natural scale model at the shaking table subjected to severe seismic accelerations up to 20 m/s2. However, viscoelastic dampers as a dynamic protection device have frequency-dependent dynamic characteristics, which are difficult to reproduce in the frame of conventional seismic analysis based typically on the use of response spectrum method. For example, the dynamic properties of viscoelastic dampers exhibit nonlinear dependence on dissipation energy, shear rate of viscous fluid, and temperature. Method for Seismic analysis of systems with viscoelastic dampers (SAVD-Method) is one of the analytical approaches capable of considering the dynamic properties and nonlinear behavior of viscoelastic dampers. The SAVD-Method is a comparatively simple but reliable approach for dynamic analysis of a piping system and components with viscoelastic dampers. Frequency-dependent dynamic characteristics of the viscoelastic dampers are able to be modeled by a four-parameter Maxwell model. To consider the nonlinearity of the dynamic properties of viscoelastic dampers, the Maxwell model parameters were determined for different usage conditions in conjunction with the adjustment dependent on the energy dissipation criteria. Direct comparison of the shaking table measurements and analysis according to SAVD-method shows good matching of results for all controlled parameters and levels of seismic excitation.

Nonlinear dynamic analysis using the pseudo-force method and the Lanczos algorithm

1988 ◽  
Vol 30 (4) ◽  
pp. 979-983 ◽  
Author(s):  
F.Venâncio Filho ◽  
Alvaro L.G.A. Coutinho ◽  
Luiz Landau ◽  
Edison C.P. Lima ◽  
Nelson F.F. Ebecken
Keyword(s):  
Dynamic Analysis ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Lanczos Algorithm ◽  
Force Method
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