The Qualification of Safety Critical Structures by Finite Element Analytical Methods

Author(s):  
A J Morris

The paper introduces the concept of certifying or qualifying structures in a safety critical situation using the finite element method. Error control and error treatment methods for this purpose are discussed together with the associated role of testing. The underlying methodology follows the principles laid down in the SAFESA (SAFE Structural Analysis) method which is described in outline.

Author(s):  
Er. Hardik Dhull

The finite element method is a numerical method that is used to find solution of mathematical and engineering problems. It basically deals with partial differential equations. It is very complex for civil engineers to study various structures by using analytical method,so they prefer finite element methods over the analytical methods. As it is an approximate solution, therefore several limitationsare associated in the applicationsin civil engineering due to misinterpretationof analyst. Hence, the main aim of the paper is to study the finite element method in details along with the benefits and limitations of using this method in analysis of building components like beams, frames, trusses, slabs etc.


2019 ◽  
Vol 794 ◽  
pp. 220-225
Author(s):  
Daiki Towata ◽  
Yuichi Tadano

In this study, a novel numerical method to analyze the bifurcation problemof a rate dependent material using the finite element method is proposed. The consistent stiffness matrix, which is required for a bifurcation analysis using the finite element method, for a rate dependent material is generally hard to compute, therefore, a computational method to calculate the tangent stiffness matrix based on a numerical differential is introduced so that exact bifurcation analyses for the rate dependent material can be conducted. A numerical example of the proposed method is demonstrated, and the adequacy of the proposed method is discussed.


Author(s):  
Jianrong Zou ◽  
Shaochong Zhou

The main equipments of the reactor coolant system include the steam generator, the reactor coolant pump, the pressurizer and the reactor coolant loop. The reactor coolant system is equipped with a steam generator for each of the two loops, and pressurizer is connected with the hot leg of loop 1 using the surge line. The main loop support system design of AP series greatly simplifies the RCS loop support system. Pressurizer supports consist of columns, lower lateral supports, upper lateral support and ring girder, and the steam generator supports consist of columns, lower lateral supports, upper lateral supports and intermediate lateral supports. Ring Girder of pressurizer consists of two semi-circular girders, vertical supports and splice connection of girder and the two half-ring girders are connected with splice connection using 11 bolts. The steam generator upper lateral support is mainly composed of bracket, snubber, pin and ubar and the ubar and the steam generator is connected via 16 bolts in the initial design. These bolts are to ensure the support junction can withstand the force and torque of various conditions of the reactor coolant system, which are important components of the main equipment support. There are large numbers of bolts in the splice connection of ring girder and ubar of upper lateral support of steam generator, and the bolts load was calculated using the uniform method in the general engineering design and analysis. During the design review it was found that the bolts load was uneven and in order to determine the non-uniformity of the bolts the finite element method was used to calculate the load on each bolt, and the resulting stress ratio was greater than 1 did not meet the requirements of the ASME Code. In this paper, the calculation method was studied and the design improvements for parts was made using the nonlinear analysis method to meet the requirements of ASME Code in the case of master supports of main equipment supports have been made good. At the same time the impact of bolts load because of gap was studied. It had very good economic benefits. The calculation and research of this paper show that the finite element method can calculate the force of bolts finely, and can get a more reasonable result than the empirical formula. It can be referred to when the multi-bolt connection structure needs to be refined, such as flange connection of important equipments and valves and flange and bolt design optimization.


2021 ◽  
Vol 83 (5) ◽  
pp. 9-17
Author(s):  
Supandi Sujatono

The content of level has a big enough role in the value of the physical characteristic and the mechanical of material. The behavior of water in these materials needs to be analyzed first in order to support the slope stability analysis. Modeling of water behavior in materials in the construction of Tailing Storage Facilities (TSF) will be integrated in the slope stability analysis. This study aims to provide an explanation about the analysis of the Fishing Storage Facilities (TSF) which integrates transient groundwater analysis using the finite element method in supporting the stability analysis of the embankment of Tailing Storage Facilities (TSF). The variables that are used in the analysis, they are the parameters of physical properties and mechanic material for embankment and permeability parameters in analyzing groundwater. The analysis method for geotechnical and geohydrology modeling uses the finite element method. The results of analysis showed that groundwater behavior in the embankment material can be known in detail so that it can be integrated with stability analysis.   It can be seen that there is a decrease in the value of the slope safety factor using the Integrated Slope Stability Analysis method compared to the conventional method. Adding an impermeable layer using a thickness of 5 m of clay material and a thickness of 20-30 m to support the retaining wall/foot is the criterion of optimal stability. The required lining material thickness (D) can be expressed by the following drawdown percentage equation function:  reduction percentage = (1-0.8661D (-0.031)) * 100%.  


Author(s):  
Yukihiro Iwata ◽  
Hiroto Inoue ◽  
Kenji Tsuji ◽  
Kazuhiko Hosokawa

Abstract Concerning the development of portable optical disk products, higher impact resistant of the optical pick-up is required. Conventionally, cut and try measures, mainly based on experiment were applied to these problems, and it took much time and cost. Therefore, we developed this drop impact analysis of the optical pick-up based on the Finite Element Method (FEM) and clarified the failure mechanism of the suspension wire breaking with drop impact. With this analysis method, we also developed a new optical pick-up with a curved suspension wire, and realized much higher impact resistance.


2009 ◽  
Author(s):  
Irina N. Sidorenko ◽  
Jan Bauer ◽  
Roberto Monetti ◽  
Dirk Müller ◽  
Ernst J. Rummeny ◽  
...  

2013 ◽  
Vol 831 ◽  
pp. 120-123
Author(s):  
Hitoshi Mitsunaga ◽  
Tomoe Kirita ◽  
Takashi Hara

This paper presented the result of analysis about R/C arch by use of finite element method. The design method for R/C shell has not been established due to its numerical difficulties. Using the finite element method, it was possible to analyze these structures. However, the precise experiments were required to verify the reliability of these analyses and it was necessary to improve the numerical analyses. An R/C arch is a basic form of the R/C shell. Under various conditions, that was, R/C arch without initial imperfection, different rise-span ratio, three types of loading points and supporting conditions, loading tests of R/C arch were performed. After experiment, analysis was also carried out. And as the result compared experimental and numerical results, accuracy of this analysis method was elucidated.


2017 ◽  
pp. 69-85
Author(s):  
Mariusz MAGIER ◽  
Adrian Nowak ◽  
Tomasz , MERDA ◽  
Paweł Żochowski

The paper presents simulation of flight path of an arrow shot with a longbow and its penetration process through a steel plate imitating an armor of a medieval heavy cavalry knights used during the Battle of Crécy on 26 August, 1346. The battle was a turning moment which had settled the specific role of the English bow in tactics and methods of its deployment on battle fields for almost 200 years until the firearms such as arquebuses or muskets started to be commonly used. The basic technical parameters necessary for the simulation process are based on historical information. On the basis of numerical calculations, the parameters of the flight path of the arrow with the "anti-armor" head were determined up to the maximum range. Thanks to use of the finite element method (AUTODYN) the penetration capacity of the arrow shot from longbow against horseman’s armor of XIV century was estimated.


2019 ◽  
Vol 18 (03) ◽  
pp. 1950013
Author(s):  
Z. Hashemi ◽  
M. R. Monazzam ◽  
A. Fahim

Perforated panels are one of the structures that are widely used nowadays. The sound absorption behavior of materials is studied by solving the equations governing the wave propagation in these materials. In this paper, the finite element method (FEM) was used to predict the absorption performances of few different perforated composite panels. Also, the studied structures were examined by two-microphone impedance tube to validate the results of the numerical method. The relative consistency of the results of the current method with the results of the impedance tube suggests the accuracy of this method in simulating the absorption rate of perforated composites. In addition, the results of evaluating various layouts (arrangements) showed that the use of absorber materials with higher flow resistivity at the back of the perforated panel and at the beginning of the sound wave entry increases the absorption performance by 1.6 times than that of the inverse layout ratio.


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