Creative Design-by-Analysis Solutions Applied to High-Temperature Components

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.

2014 ◽  
Vol 919-921 ◽  
pp. 1016-1019 ◽  
Author(s):  
Xue Yu Xiong ◽  
Rong Jun Xue ◽  
Sen Zhang ◽  
Li Jun Wang

The masonry building takes a majority of town housings in these areas. Unlike the experimental study, the Finite Element Analysis is an important part for better comprehension of the finite element method and can reduce the investment and manpower. The aim of this paper is to simulate the structural response from the variety of masonry buildings under earthquake excitations by using finite element software called ABAQUS. There are four models of the masonry building with different storey, which include the one without constructional column and ring beam, with constructional column only, with ring beam only and with constructional column and ring beam simultaneously. In the process of modeling, we adopt the integrated model and regard walls, constructional columns, slabs and steels as homogenous continuums. Furthermore, we adopt concrete damaged plasticity material model to simulate the material of building and input El Centro earthquake wave N-S component. The result of analysis shows that setting ring beams or constructional columns can significantly improve the integrity of the building and reduce the mises stress on foundation. The result of analysis has a significant guidance on masonry building construction in seismic region.


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.   


Author(s):  
Rama Subba Reddy Gorla

Heat transfer from a nuclear fuel rod bumper support was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties in the performance parameters. Cumulative distribution functions and sensitivity factors were computed for overall heat transfer rates due to the thermodynamic random variables. These results can be used to identify quickly the most critical design variables in order to optimize the design and to make it cost effective. The analysis leads to the selection of the appropriate measurements to be used in heat transfer and to the identification of both the most critical measurements and the parameters.


2013 ◽  
Vol 690-693 ◽  
pp. 2327-2330
Author(s):  
Ming Bo Han ◽  
Li Fei Sun

By using finite element software, the paper establishes the main stand analysis model of the Ф140 pipe rolling mill and provides the model analysis of main stand in cases of full load. Verify the design of main stand fully comply with the technical requirements .In this paper, it provides the theoretical position of split casting and welding method using electric slag welding.


1999 ◽  
Vol 122 (1) ◽  
pp. 22-26 ◽  
Author(s):  
M. Law ◽  
W. Payten ◽  
K. Snowden

Modeling of welded joints under creep conditions with finite element analysis was undertaken using the theta projection method. The results were compared to modeling based on a simple Norton law. Theta projection data extends the accuracy and predictive capability of finite element modeling of critical structures operating at high temperature and pressure. In some cases analyzed, it was found that the results diverged from those gained using a Norton law creep model. [S0094-9930(00)00601-6]


2014 ◽  
Vol 898 ◽  
pp. 399-402
Author(s):  
Heng Sun ◽  
Bai Shou Li

For traditional ordinary concrete wall column prone to thermal bridges, posted outside the insulation board short life than the life of the building,in the glazed hollow bead of recycled concrete foundation with good thermal conductivity test and compressive strength of the proposed ,use glazed hollow bead of recycled concrete exterior wall column instead of the traditional ordinary concrete wall column ,and using the finite element software ANSYS simulation analysis the uniaxial compression of glazed hollow bead of recycled concrete short columns and ordinary concrete short columns. Comparative analysis showed the same intensity level glazed hollow bead of recycled concrete ultimate compressive bearing capacity of an analog value the same as ordinary concrete short columns. To validate the ANSYS simulation of concrete short columns under uniaxial compression condition .


2011 ◽  
Vol 2-3 ◽  
pp. 140-143
Author(s):  
Qing Feng Yang ◽  
Peng Wang ◽  
Yu Hong Wang ◽  
Kai Zhang

The resonance frequency of the cymbal transducer ranges from 2kHz to 40kHz and its effective electromechanical coupling factor is around 20%. Finite element analysis has been performed to ascertain how the transducer’s makeup affect the transducer’s performance parameters. Two-dimensional axisymmetric model of the cymbal transducer was founded by finite element software-ANSYS, the application of the element type was discussed and the FEM models were built up under the far field condition. Eight groups of cymbal transducers of resonance frequency around 3kHz with different structural dimensions were designed. It was better for choosing the cymbal transducer of the 8mm cavity coping diameter, 20.8mm cavity bottom diameter and 26.8mm piezoelectric ceramic wafer diameter than others for reducing distortion degree of the signal and improving communication turnover in the researched cymbal transducers. It was appropriate for choosing the cymbal transducer of the 8mm cavity coping diameter, 22.4mm cavity bottom diameter and 26.4mm piezoelectric ceramic wafer diameter in order to improve the free-field voltage sensitivity and transmission efficient.


2009 ◽  
Vol 33 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Mohamed Nizar Bettaieb ◽  
Mohamed Maatar ◽  
Chafik Karra

The purpose of this work is to determine the spur gear mesh stiffness and the stress state at the level of the tooth foot. This mesh stiffness is derived from the calculation of the normal tooth displacements: local displacement where the load is applied, tooth bending displacement and body displacement [15]. The contribution of this work consists in, basing on previous works, developing optimal finite elements model in time calculation and results precision. This model permits the calculation of time varying mesh stiffness and the evaluation of stress state at the tooth foot. For these reasons a specific Fortran program was developed. It permit firstly, to obtain the gear geometric parameters (base radii, outside diameter,…) and to generate the data base of the finite element meshing of a tooth or a gear. This program is interfaced with the COSMOS/M finite element software to predict the stress and strain state and calculate the mesh stiffness of a gear system. It is noted that the mesh stiffness is periodic and its period is equal to the mesh period.


2018 ◽  
Vol 29 (16) ◽  
pp. 3188-3198 ◽  
Author(s):  
Wissem Elkhal Letaief ◽  
Aroua Fathallah ◽  
Tarek Hassine ◽  
Fehmi Gamaoun

Thanks to its greater flexibility and biocompatibility with human tissue, superelastic NiTi alloys have taken an important part in the market of orthodontic wires. However, wire fractures and superelasticity losses are notified after a few months from being fixed in the teeth. This behavior is due to the hydrogen presence in the oral cavity, which brittles the NiTi arch wire. In this article, a diffusion-mechanical coupled model is presented while considering the hydrogen influences on the NiTi superelasticity. The model is integrated in ABAQUS finite element software via a UMAT subroutine. Additionally, a finite element model of a deflected orthodontic NiTi wire within three teeth brackets is simulated in the presence of hydrogen. The numerical results demonstrate that the force applied to the tooth drops with respect to the increase in the hydrogen amount. This behavior is attributed to the expansion of the NiTi structure after absorbing hydrogen. In addition, it is shown that hydrogen induces a loss of superelasticity. Hence, it attenuates the role of the orthodontic wire on the correction tooth malposition.


Author(s):  
H. Teng ◽  
D. W. Beardsmore ◽  
J. K. Sharples ◽  
P. J. Budden

A finite element analysis has been performed to investigate the effects of warm prestressing of a pre-cracked PTS-D (Pressurized Thermal Shock Disk) specimen, for comparison with the experimental work conducted by the Belgium SCK-CEN organisation under the European NESC VII project. The specimen was loaded to a maximum loading at −50 °C, unloaded at the same temperature, cooled down to −150 °C, and then re-loaded to fracture at −150 °C. This is a loading cycle known as a LUCF cycle. The temperature-dependant tensile stress-strain data was used in the model and the finite element software ABAQUS was used in the analysis. The finite element results were used to derive the apparent fracture toughness by three different methods: (1) Chell’s displacement superposition method; (2) the local stress matching method; and (3) Wallin’s empirical formula. The apparent fracture toughness values were derived at the deepest point of the semi-elliptical crack for a 5% un-prestressed fracture toughness of 43.96 MPam1/2 at −150 °C. The detailed results were presented in the paper.


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