Modelling of Flexible Victaulic Couplings Using Basic Finite Element Software

Author(s):  
Roman W. Motriuk

In the past decade, Victaulic couplings have gained significant recognition as important piping elements, which are used mainly in water and slurry transportation systems. For example, grooved flexible Victaulic couplings offered significant economical and reliable piping connections when compared to other connecting elements such as flanges. Victaulic couplings are on average three times faster to install than welding piping connections. They are more reliable and cost-effective than flanges or threaded connectors. In addition, the speed and easiness of their assembly or disassembly as well as their flexibility and ability to provide thermal gaps make the couplings desirable as piping elements. Furthermore, the couplings provide stress designers with a rare opportunity to cheaply and reliably compensate for piping loads which are otherwise exerted on equipment attached to piping. For the above reasons Victaulic couplings are frequently used in current piping designs. In spite of their simple design and application they pose a significant challenge for stress designers. The stress software packages based on piping finite element theories which are commonly used in industry do not provide the means to model Victaulic couplings adequately. These packages are based on stress linear theories, and Victaulic couplings with their gaps are definitely non-linear elements. Therefore, the approach to model these elements is very approximate and is usually done by the use of nonlinear restraints built into the software. The stiffness and friction for Victaulic coupling “restraints” are rarely known and assumptions of their values have to be made in order to carry out calculations. Therefore, the prescribed values for the restraints directly influence the stress results. This work discusses assumptions based on several simple stress models. An attempt is made by the author to minimize conservatism as much as practical in the modelling of Victaulic couplings, while waiting for the manufacturers of these elements to test their products and provide meaningful statistical information, which could then be used to carry out stress predictions. The couplings’ stiffness, bending moment and axial force capabilities provided in this work must not be used for design purposes unless verified and accepted by the couplings’ manufacturers.

2013 ◽  
Vol 671-674 ◽  
pp. 974-979
Author(s):  
Jie Dai ◽  
Jin Di ◽  
Feng Jiang Qin ◽  
Min Zhao ◽  
Wen Ru Lu

For steel box girder of cable-stayed bridge, which using incremental launching method, during the launching process, structural system and boundary conditions were changing, structure mechanical behaviors were complex. It was necessary to conduct a comprehensive analysis on internal force and deformation of the whole structure during the launching process. Took a cable-stayed bridge with single tower, double cable planes and steel box girder in China as an example; finite element software MIDAS Civil 2010 was used to establish a model for steel box girder, simulation analysis of the entire incremental launching process was carried out. Variation rules and envelopes of the internal force, stress, deformation and support reaction were obtained. The result showed that: the maximum value of positive bending moment after launching complete was 60% of the maximum value of positive bending moment during the launching process. The maximum value of negative bending moment after launching complete was 78% of the maximum value of negative bending moment during the launching process.


1993 ◽  
Vol 115 (3) ◽  
pp. 221-227
Author(s):  
A. K. Dhalla

Elevated temperature design has evolved over the last two decades from design-by-formula philosophy of the ASME Boiler and Pressure Vessel Code, Sections I and VIII (Division 1), to the design-by-analysis philosophy of Section III, Code Case N-47. The benefits of design-by-analysis procedures, which were developed under a US-DOE-sponsored high-temperature structural design (HTSD) program, are illustrated in the paper through five design examples taken from two U.S. liquid metal reactor (LMR) plants. Emphasis in the paper is placed upon the use of a detailed, nonlinear finite element analysis method to understand the structural response and to suggest design optimization so as to comply with Code Case N-47 criteria. A detailed analysis is cost-effective, if selectively used, to qualify an LMR component for service when long-lead-time structural forgings, procured based upon simplified preliminary analysis, do not meet the design criteria, or the operational loads are increased after the components have been fabricated. In the future, the overall costs of a detailed analysis will be reduced even further with the availability of finite element software used on workstations or PCs.


2010 ◽  
Vol 456 ◽  
pp. 103-114
Author(s):  
Shi Ling Xing ◽  
Jian Shu Ye ◽  
Hang Sun

In order to use finite element software to complete the design or calculation of bridge multi-pile foundation, this paper discusses the finite element model (FEM) of a bridge multi-pile based on the theory and provisions in Code for Design of Ground Base and Foundation of Highway Bridges and Culverts (CDGBFHBC 2007) of china. For the FEM of a bridge-multi pile foundation, cap is regarded as a rigid body, piles are taken as beams, and boundary constraints are a series of horizontal springs and vertical springs. First, the formula of stiffness for horizontal springs and bottom vertical spring is derived according to elastic ground base theory and winkler hypotheses. Secondly, for the friction pile, the stiffness of vertical springs on piles side is derived basis of the principle of friction generated and simplified distribution of pile shaft resistance. Then, the FEM of multi-pile needs pay attention to three issues: the simulation of connections between piles and cap, elastic modulus needs discount, and the weight for pile underneath the ground line (or local scour line) needs calculate by half. Taking pile section bending moment often control the design and calculation of pile into account, this paper gives a simplified FEM of pile. Finally, an example is used to introduce the application of the FEM of bridge multi-pile foundation.


Author(s):  
Jiayue Liu ◽  
Mehrdad Kimiaei ◽  
Mark Randolph

Steel Catenary Risers (SCRs) provide a technically feasible and commercially efficient solution for the offshore field developments in deep waters. Fatigue design of SCRs in the touchdown zone (TDZ) is among the most complicated engineering challenges in riser design. The cyclic interaction of the riser with seabed leads to a number of complex nonlinear behaviors including soil suction, separation of the riser from the soil, trench formation and degradation of soil resistance during cyclic loading. Accurate simulation of the riser-soil interaction has significant effects on the fatigue performance in the TDZ. Few hysteretic nonlinear riser-soil interaction models have recently been introduced and some of them have been implemented in commercial software packages for analysis and design of riser systems. Due to complexity of the models and also limited access to special software packages with in-built nonlinear soil models, traditional simple linear soil models are still being used widely for riser analysis, in particular for fatigue design. In this paper, one of the existing nonlinear hysteretic seabed model, already been used in a commercial analysis program OrcaFlex [1], has been implemented into general finite element software Abaqus [2], through the coding of a user defined element (UEL) subroutine. The paper documents the implementation of UEL into Abaqus and the establishment of global riser model for both static and dynamic analysis on which the pipe is modelled efficiently as series of unidirectional beam elements from floater to seabed, resting on a bed of nonlinear springs. Longitudinal friction between pipe and seabed has also been considered. A series of simulations are performed to illustrate the capabilities of the model. All these results have good agreement with those from OrcaFlex. Results indicate that the proposed UEL is capable of modelling nonlinear riser-soil interaction phenomena and has been verified to be a cost-effective alternative to OrcaFlex in terms of global analysis of SCRs. In addition, as an open source code, UEL provides the required tool for future development on nonlinear soil models. A new type of nonlinear soil with bilinear soil shear strength is modeled and its effect on structural performances of SCRs is investigated.


Author(s):  
Yong Bai ◽  
Jiannan Zhao ◽  
Xinyu Sun ◽  
Xiaojie Zhang ◽  
Zhao Wang

Abstract Fiber glass reinforced flexible pipe (FGRFP) is a kind of submarine pipe widely used in oil and gas transportation and exploration. This paper mainly studies the theoretical and numerical simulation methods for calculating the fatigue life of the FGRFP. Firstly, the tension time-histories and bending moment time-histories of the FGRFP are obtained by using global analysis. The tension and bending moment frequency distribution histograms are obtained by using rain flow method. Then, the finite element software ABAQUS is used to build the model of the FGRFP, and the corresponding tension and bending moment are applied on the finite element model. Then, the stress time histories curve of the FGRFP is obtained. By comparing the results of numerical simulation, the main factors affecting the fatigue life of the FGRFP are studied. Finally, according to rain flow method, S-N curve and numerical simulation results, the fatigue life and single damage rate of FGRFP are obtained.


2020 ◽  
Vol 165 ◽  
pp. 04039
Author(s):  
Teng Ma ◽  
Jingkai Zhao ◽  
Dafang Mei

In order to explore the rational suspender layout of reticulated suspender steel box tied arch bridge, eight different suspender layout schemes were established by using finite element software Midas civil, taking a real bridge as the background and the constant inclination angle of suspender as the research variable. The structural stress characteristics of vertical suspender and reticulated suspender layout were analyzed and compared. The results show that the bending moment of arch rib and tied beam of reticulated suspender system is smaller, and the stress of arch beam is closer to the ideal state of “arch rib is compressed, tied beam is pulled”. The results show that in the range of 60 ~90, the smaller the inclination angle is, the more favorable the stress of the structure is, but the lower the moment reduction efficiency is when the inclination angle of the suspender is less than 60.


2014 ◽  
Vol 611-612 ◽  
pp. 545-552
Author(s):  
Komi Soho ◽  
Farid Abed Meraim ◽  
Xavier Lemoine ◽  
Hamid Zahrouni

For the numerical simulation of sheet metal forming processes, the commercial finite element software packages are among the most commonly used. However, these software packages have some limitations; in particular, they essentially contain phenomenological constitutive models and thus do not allow accounting for the physical mechanisms of plasticity that take place at finer scales as well as the associated microstructure evolution. In this context, we propose to couple the Abaqus finite element code with micromechanical simulations based on crystal plasticity and a self-consistent scale-transition scheme. This coupling strategy will be applied to the simulation of rolling processes, at different reduction rates, in order to estimate the evolution of the mechanical properties. By following some appropriately selected strain paths (i.e., strain lines) along the rolling process, one can also predict the texture evolution of the material as well as other parameters related to its microstructure. Our numerical results are compared with experimental data in the case of ferritic steels produced by ArcelorMittal.


2018 ◽  
Vol 7 (3.10) ◽  
pp. 103
Author(s):  
T Subramani ◽  
R Nashreen

In the modern trend peoples are looking for alternate material which is cost effective and high stability in while subject to dynamic loading. Considering this as one of the factor in our proposed we choose steel scrap as reinforced material which has high durability and strength. To find out the withstanding capacity of  the dynamic loading model the structure using finite element software and analysis to predict the safety of the structure. From the analysis result we conclude for preventive measure of the structural failure and utilization of extra dampers has find out. To validating the result, analytical work is carried out and implemented by using ETAB software.   


2011 ◽  
Vol 250-253 ◽  
pp. 1483-1488
Author(s):  
Jin Song Gui ◽  
Zhen Guo Li ◽  
Qing Meng ◽  
Bo Zhang

The value selection of m has a greater influence on the internal force of pile. So, how to determine the value of m is very important for the “m” method. In this paper, a geotechnical finite element software PLAXIS is used for the nonlinear finite element analysis of elastic long pile under the horizontal force action. By using the calculated maximum bending moment and the maximum displacement at the ground, and combined with the related formula for “m” method given in 《Code for Pile Foundation of Harbour Engineering》, a more accurate value of m can be obtained conveniently. Because this method is simple and practical, it can provide a useful reference for the project designer to determine a reasonable value of m.


2014 ◽  
Vol 670-671 ◽  
pp. 755-758
Author(s):  
An Ning Zhang ◽  
Yu Ming Gu

This paper studied the difference between the segment loading static analysis method and the uniform loading static analysis method on the mobile refuge chamber. The structure strength static analysis of the mobile refuge chamber was made in the uniform and segment loading ways by the finite element software SolidWorks Simulation. The stress cloud charts and the displacement cloud charts were obtained. The comparison result indicates that the results of the segment loads method are less than those of the uniform loading method and is closer to those of the dynamic analysis method. Therefore the segment loading static analysis method is better than the uniform loading one.


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