scholarly journals FINITE ELEMENT ANALYSES FOR ULTIMATE BEHAVIORS OF PRESTRESSED CONCRETE CONTAINMENT VESSEL SUBJECTED TO INTERNAL PRESSURE : Part 1 Global analyses for 1/4 PCCV test model

Author(s):  
Takanori OGATA ◽  
Kenji YONEZAWA ◽  
Katsuyoshi IMOTO ◽  
Hitoshi MAENO
Author(s):  
Barry Millet ◽  
Kaveh Ebrahimi ◽  
James Lu ◽  
Kenneth Kirkpatrick ◽  
Bryan Mosher

Abstract In the ASME Boiler and Pressure Vessel Code, nozzle reinforcement rules for nozzles attached to shells under external pressure differ from the rules for internal pressure. ASME BPVC Section I, Section VIII Division 1 and Section VIII Division 2 (Pre-2007 Edition) reinforcement rules for external pressure are less stringent than those for internal pressure. The reinforcement rules for external pressure published since the 2007 Edition of ASME BPVC Section VIII Division 2 are more stringent than those for internal pressure. The previous rule only required reinforcement for external pressure to be one-half of the reinforcement required for internal pressure. In the current BPVC Code the required reinforcement is inversely proportional to the allowable compressive stress for the shell under external pressure. Therefore as the allowable drops, the required reinforcement increases. Understandably, the rules for external pressure differ in these two Divisions, but the amount of required reinforcement can be significantly larger. This paper will examine the possible conservatism in the current Division 2 rules as compared to the other Divisions of the BPVC Code and the EN 13445-3. The paper will review the background of each method and provide finite element analyses of several selected nozzles and geometries.


2013 ◽  
Vol 284-287 ◽  
pp. 1441-1445
Author(s):  
Doo Yong Cho ◽  
Sun Kyu Park ◽  
Woo Seok Kim

This paper presents the live load distribution in straight prestressed concrete (PSC) girder bridges with curved deck slab utilizing finite element analyses. Numerical modeling methodology was established and calibrated based on field testing results. A parametric study of 73 cases with varying 6 critical parameters was used to determine a trend over each parameter. Through live load girder distribution factor (GDF) comparisons between the AASHTO LRFD, AASHTO Standard factors and finite element analyses results, both AASHTO live load distribution predicted conservatively in most bridges considered in the parametric study. However, in the bridges with curved slab, GDF was underestimated due to curvature influences. This study proposes a new live load distribution formula to predict rational and conservative live load distribution in PSC girder bridges with curved slab for a preliminary design purpose. The proposed live load distribution provides better live load analysis for the PSC girder bridge with curved slab and ensures the GDF is not underestimated.


1971 ◽  
Vol 93 (4) ◽  
pp. 905-912 ◽  
Author(s):  
R. C. Gwaltney ◽  
J. M. Corum

Compact reinforcement for a series of models having single nozzles radially attached to spherical shells was examined by means of finite element analyses. Parameters studied were diameter-to-thickness ratios of the nozzles, diameter-to-thickness ratios of the spherical shells, percentage of reinforcement, outside reinforcement, inside reinforcement, and “balanced” reinforcement (reinforcement on both the inside and outside surfaces). The loading was internal pressure. Comparisons of theoretical predictions with experimental results are presented for one reinforced model. Twelve models were analyzed to examine the effect of compact reinforcement.


Author(s):  
Yasumi Kitajima ◽  
Satoru Shibata

We conducted the limit state tests of cylindrical shells to establish criteria for the occurrence of steel wall/liner tearing in the reactor containment vessels (such as Steel Containment Vessels (SCV), Prestressed Concrete Containment Vessels (PCCV) and Reinforced Concrete Containment Vessels (RCCV)) under the limit state pressure. In the tests, precisely manufactured cylindrical shell vessels (about 800 mm in height and 300 mm in diameter) were pressurized to the failure using water. We also conducted the finite element analyses. The conclusions are as follows: 1. We obtained good agreement (within 2–3%) between the tests and the analyses in structural behavior such as internal pressure loading vs. displacement and strain to the failure. However, in the case of the test piece which included weld line on the cylindrical wall, the difference between the tests and the analyses was larger (about 1.5 times) than the rest. 2. The localized strains began to increase when radial strains in general structure reached 5–10%. We are intended to apply these results to the finite element analyses and the integrity evaluation of containment vessels (SCV, PCCV and RCCV).


2004 ◽  
Vol 126 (2) ◽  
pp. 179-183 ◽  
Author(s):  
Do-Jun Shim ◽  
Jae-Boong Choi ◽  
Young-Jin Kim

Failure assessment of a pipe with local wall thinning draws increasing attention in the nuclear power plant industry. Although many guidelines have been developed and are used for assessing the integrity of a wall-thinned pipeline, most of these guidelines consider only pressure loading and thus neglect bending loading. As most pipelines in nuclear power plants are subjected to internal pressure and bending moment, an assessment procedure for locally wall-thinned pipeline subjected to combined loading is urgently needed. In this paper, three-dimensional finite element (FE) analyses are carried out to simulate full-scale pipe tests conducted for various shapes of wall-thinned area under internal pressure and bending moment. Maximum moments based on ultimate tensile stress were obtained from FE results to predict the failure of the pipe. These results are compared with test results, showing good agreement. Additional finite element analyses are then performed to investigate the effect of key parameters, such as wall-thinned depth, wall-thinned angle and wall-thinned length, on maximum moment. Moreover, the effect of internal pressure on maximum moment was investigated. Change of internal pressure did not show significant effect on the maximum moment.


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