Finite element analysis of hydrogen diffusion/plasticity coupled behaviors of low-alloy ferritic steel at large strain

2017 ◽  
Vol 42 (31) ◽  
pp. 20324-20335 ◽  
Author(s):  
T.C. Cui ◽  
P.F. Liu ◽  
C.H. Gu
2014 ◽  
Vol 76 ◽  
pp. 281-293 ◽  
Author(s):  
Dong Jun Lee ◽  
Eun Yoo Yoon ◽  
Dong-Hyun Ahn ◽  
Byung Ho Park ◽  
Hyo Wook Park ◽  
...  

1988 ◽  
Vol 61 (5) ◽  
pp. 879-891 ◽  
Author(s):  
Robert H. Finney ◽  
Alok Kumar

Abstract The determination of the material coefficients for Ogden, Mooney-Rivlin, Peng, and Peng-Landel material models using simple ASTM D 412 tensile data is shown to be a manageable task. The application of the various material models are shown to be subject to the type and level of deformation expected, with Ogden showing the best correlation with experimental data over a large strain range for the three types of strain investigated. At low strains, all of the models showed reasonable correlation.


2009 ◽  
Vol 2009.22 (0) ◽  
pp. 270-271
Author(s):  
Reza Miresmaeili ◽  
Hirofumi Notsu ◽  
Takuya Nakagawa ◽  
Jean-Marc Olive ◽  
Masao Ogino ◽  
...  

Author(s):  
Donald J. Florizone

Traditional design techniques result in excess material being required for ellipsoidal heads. The 2001 ASME Boiler and Pressure Vessel Code Section VIII Division 1, UG-32D and Section VIII Division 2, AD-204 limit the minimum design thickness of the heads. ASME Boiler and Pressure Vessel Code Case 2261 provides alternate equations that enable thinner head design thickness. VIII-2 Appendix 3 and 4 methods potentially could be used to further optimize the head thickness. All the equations in the code use one thickness for the entire head. On large diameter thin heads the center or spherical area is often thicker than the knuckle area due to the method of manufacture. Including this extra material in the design calculations results in an increase of the MAWP of large diameter thin heads. VIII-2, AD-200 of the code permits localized thinning in a circumferential band in a cylindrical shell. Applying these same rules to elliptical heads would permit thinning in the knuckle region as well. Engineers have powerful finite element analysis tools that can be used to accurately determine levels of plastic strain and plastic deformed shapes. It is proposed that VIII-2 Appendix 4 and 5 methods be permitted for the design of elliptical heads. Doing so would permit significant decreases in thickness requirements. Different methods of Plastic Finite Element Analysis (PFEA) are investigated. An analysis of a PVRC sponsored burst test is done to develop and verify the PFEA methods. Two designs based on measurements of actual vessels are analyzed to determine the maximum allowable working pressures (MAWP) for thick and thin heads with and without local thin regions. MAWP is determined by limit analysis, per VIII-2 4-136.3 and by two other proposed methods. Using Burst FEA, the calculated burst pressure is multiplied by a safety factor to obtain MAWP. Large deflection large strain elastic perfectly plastic limit analyses (LDLS EPP LL) method includes the beneficial effect of deformations when determining the maximum limit pressure. Elliptical heads become more spherical during deformation. The spherical shape has higher pressure restraining capabilities. An alternate design equation for elliptical heads based on the LDLS EPP LL calculations is also proposed.


Author(s):  
W.D. Liam Finn

There are three levels of analysis for assessing the postliquefaction stability of embankments: limit equilibrium analysis using residual strength, Newmark sliding block analysis using residual strength, and finite element large strain displacement analysis. The first two types are well known and often used. In recent years, finite element analysis has been used increasingly for important projects involving life safety and large remediation costs. The application of finite element analysis is illustrated by two case histories—failure of a river protection dike in Japan, and the seismic safety evaluation and subsequent remediation of Sardis Dam in Mississippi. The latter example is particularly relevant to pile-supported abutments because the upstream slope of the dam was nailed to a stable foundation layer using prestressed concrete piles. The determination of the static and dynamic moments and shears in these piles would not have been possible without the finite element analysis. A crucial problem affecting the reliability of all methods of analysis is determining the appropriate value for the residual strength.


2010 ◽  
Vol 2010.23 (0) ◽  
pp. _F-42_-_F-43_
Author(s):  
Lijun Liu ◽  
Reza Miresmaeili ◽  
Masao Ogino ◽  
Hiroshi Kanayama

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