Elastoplastic Analysis of Novel Parabola-Arc-Shaped Head for Internal Pressure Vessel

2015 ◽  
Vol 750 ◽  
pp. 352-362
Author(s):  
Ning Wang ◽  
Hong Qi Liu ◽  
Shan Tung Tu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Pressure Vessel ◽  
Mechanical Performance ◽  
Burst Pressure ◽  
Engineering Practice ◽  
The Novel ◽  
Limit Loads

In this paper, the elastoplastic stress analysis of a novel parabola-arc-shaped head subjected to internal pressure has been carried out using finite element method. Limit loads and burst pressures are obtained for various geometric parameters and compared with the conventional torispherical and ellipsoidal heads. For the same middle diameter and thickness, the novel parabola-arc-shaped head shows better mechanical performance than the torispherical head. The burst pressure is mainly determined by the size of cylinder and the burst always occurs in cylinder. The head can improve the burst load when the cylinder is relatively short. The improvement of the novel parabola-arc-shaped head is almost the same as the ellipsoidal head, while the torispherical head is slightly inferior. As the novel parabola-arc-shaped head can be more easily formed with less material consumed compared to the conventional ones, it should thus be applicable in engineering practice.

Stress Analysis and Stress Index Development for a Trunnion Pipe Support

1982 ◽  
Vol 104 (2) ◽  
pp. 73-78
Author(s):  
M. H. Sadd ◽  
R. R. Avent
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Wall Thickness ◽  
Pressure Vessel ◽  
Stress Index ◽  
Secondary Stress ◽  
Empirical Formulas ◽  
Stress Indices ◽  
Finite Element Stress Analysis

A finite element stress analysis is presented of a trunnion pipe anchor. The structure is analyzed for the case of internal pressure and various end moment loadings. Stress results were post-processed and decomposed into average and linear varying (through the wall thickness). These decomposed values were then interpreted within the ASME Boiler and Pressure Vessel Code to estimate primary and secondary stress indices. Several computer runs were made for a variety of structural sizes and empirical formulas were developed expressing the stress indices as a function of certain dimensionless ratios.

FEM Stress Analysis and Sealing Performance in Non-Circular Flange Connections With Gaskets Subjected to Internal Pressure

2003 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Wataru Maezaki
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Stress Distributions ◽  
Flange Connection ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Element Method

The contact gasket stress distributions of a non-circular flange connection with a compressed asbestos sheet gasket subjected to internal pressure were analyzed taking account a hysteresis of the gasket by using finite element method (FEM). Leakage tests were also conducted using an actual non-circular flange connection with a compressed asbestos sheet gasket under internal pressure. By using the contact gasket stress distributions and the results of the leakage tests, the new gasket constants were calculated. A difference in the new gasket constants between the values obtained from the present study and those by the PVRC procedure was substantial. In addition, a method to determine the initial clamping bolt force (bolt preload) for a given tightness parameter was demonstrated. abstract text here.

An Effect of Nozzle Flexibilities/Stiffness on Equipment Nozzle Loads and Local Stresses

2018 ◽  
Author(s):  
Sujay S. Pathre ◽  
K. Govindan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Analysis ◽  
Pressure Vessel ◽  
Closed Loop ◽  
Closed Loop Systems ◽  
Local Stresses ◽  
Load Evaluation ◽  
Element Method

The loads on the equipment nozzles are generally generated by the piping stress engineer by doing the stress analysis of entire closed loop systems. Subsequently the nozzle loads are passed on to the engineers of the pressure vessel equipment. The value of the loads which have been worked out for the nozzle mostly depends upon the methods/concept by which the piping stress engineer has evaluated the piping loop. Nozzle flexibility/stiffness is the important parameter in evaluation of various components of nozzle loads. The objective of this paper is to explain the effect/influence of flexibility/stiffness generated from three different methods (Anchor, WRC and Finite element method) on nozzle load evaluation and shell/nozzle junction stresses. WRC297 bulletin [6] gives the reference to nozzle flexibility in the appendix A, example no.3. The work presented in this paper is an attempt to compare the nozzle loads calculated by evaluating the flexibilities/stiffness in various methods. Further an attempt has been made to consolidate the results of junction local stresses obtained by the various methods of stiffness/flexibilities which would result in realistic results and overall code acceptable stresses without the results being either overly conservative or unconservative.

FEM Stress Analysis and an Evaluation of the Sealing Performance in Non-Circular Flange Connections With Gaskets Subjected to Internal Pressure

2006 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Ryo Kurosawa ◽  
Wataru Maezaki
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Flange Connection ◽  
Bolt Preload ◽  
Sealing Performance ◽  
The Difference

The contact gasket stress distributions of a non-circular flange connection with a compressed sheet gasket subjected to internal pressure were analyzed taking into account of the hysteresis behavior of the gasket by using the finite element method (FEM). Leakage tests were also conducted using an actual non-circular flange connection with a compressed sheet gasket under internal pressure. Using the contact gasket stress distributions and the results of the leakage tests, the new gasket constants were calculated. The difference in the new gasket constants between the values obtained from the present study and those by the PVRC procedure was substantial. In addition, a method to determine the initial clamping bolt force (bolt preload) for a given tightness parameter was demonstrated.

Stress Analysis of Tire Sections

1996 ◽  
Vol 24 (4) ◽  
pp. 349-366 ◽  
Author(s):  
T-M. Wang ◽  
I. M. Daniel ◽  
K. Huang
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Strain Analysis ◽  
Experimental Stress ◽  
Inflation Pressure ◽  
Substantial Agreement ◽  
Finite Element Stress Analysis ◽  
Strain Components ◽  
Fringe Patterns

Abstract An experimental stress-strain analysis by means of the Moiré method was conducted in the area of the tread and belt regions of tire sections. A special loading fixture was designed to support the tire section and load it in a manner simulating service loading and allowing for Moiré measurements. The specimen was loaded by imposing a uniform fixed deflection on the tread surface and increasing the internal pressure in steps. Moiré fringe patterns were recorded and analyzed to obtain strain components at various locations of interest. Maximum strains in the range of 1–7% were determined for an effective inflation pressure of 690 kPa (100 psi). These results were in substantial agreement with results obtained by a finite element stress analysis.

scholarly journals Structural Damage Identification Based on Integrated Utilization of Inverse Finite Element Method and Pseudo-Excitation Approach

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 606
Author(s):  
Tengteng Li ◽  
Maosen Cao ◽  
Jianle Li ◽  
Lei Yang ◽  
Hao Xu ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Structural Damage ◽  
Damage Identification ◽  
Displacement Measurement ◽  
Engineering Practice ◽  
Position Measurement ◽  
Inverse Finite Element Method ◽  
Pseudo Excitation ◽  
Element Method

The attempt to integrate the applications of conventional structural deformation reconstruction strategies and vibration-based damage identification methods is made in this study, where, more specifically, the inverse finite element method (iFEM) and pseudo-excitation approach (PE) are combined for the first time, to give rise to a novel structural health monitoring (SHM) framework showing various advantages, particularly in aspects of enhanced adaptability and robustness. As the key component of the method, the inverse finite element method (iFEM) enables precise reconstruction of vibration displacements based on measured dynamic strains, which, as compared to displacement measurement, is much more adaptable to existing on-board SHM systems in engineering practice. The PE, on the other hand, is applied subsequently, relying on the reconstructed displacements for the identification of structural damage. Delamination zones in a carbon fibre reinforced plastic (CFRP) laminate are identified using the developed method. As demonstrated by the damage detection results, the iFEM-PE method possesses apparently improved accuracy and significantly enhanced noise immunity compared to the original PE approach depending on displacement measurement. Extensive parametric study is conducted to discuss the influence of a variety of factors on the effectiveness and accuracy of damage identification, including the influence of damage size and position, measurement density, sensor layout, vibration frequency and noise level. It is found that different factors are highly correlated and thus should be considered comprehensively to achieve optimal detection results. The application of the iFEM-PE method is extended to better adapt to the structural operational state, where multiple groups of vibration responses within a wide frequency band are used. Hybrid data fusion is applied to process the damage index (DI) constructed based on the multiple responses, leading to detection results capable of indicating delamination positions precisely.

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