Mechanical Capacity Analysis of Large Diameter Prestressed Concrete Cylinder Pipe (PCCP)

2012 ◽  
Vol 166-169 ◽  
pp. 3214-3219
Author(s):  
Yu Liang Wang ◽  
Yong Qing Bi ◽  
Xiao Jie Zhou
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Prestressed Concrete ◽  
Design Method ◽  
Large Diameter ◽  
Elastic Plane ◽  
Element Analysis ◽  
Crack Control ◽  
Concrete Cylinder ◽  
Prestressed Concrete Cylinder Pipe

Prestressed concrete cylinder pipe(PCCP) has been applied to oil, water conservancy and hydropower engineering and other fields as a kind of high quality composite pipe. Because of its complicated structure and work condition, mechanical behavior of PCCP is not uniform. In this paper, the mechanical model is established in PCCP working stage based on the elastic plane strain theory of axisymmetric multilayer cylinders and the mechanism of the ring-like strands action. Then the design method of prestressing is put forward according to the aim at the crack control. The stress is analyzed with finite-element analysis in the condition of different pressure, and also the method is amended compared with the finite-element analysis. It is indicated that the design method of prestressing is reasonable compared with specification of both domestic and international.

FINITE ELEMENT ANALYSIS OF PRESTRESSED CONCRETE VOIDED BRIDGE DECKS

PCI Journal ◽  
1973 ◽  
Vol 18 (3) ◽  
pp. 51-66 ◽  
Author(s):  
J. C. Jofriet ◽  
G. M. McNeice ◽  
P. Csagoly
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Prestressed Concrete ◽  
Bridge Decks ◽  
Element Analysis

Finite Element Analysis and Optimization of Long-Span Gantry NC Machining Center Structure

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Dynamic Performance ◽  
Plate Thickness ◽  
Element Model ◽  
Wall Structure ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Performance Analysis

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.

Standardization of Flattening Procedure of Transverse to Pipe Axis Strap Tensile Samples

2018 ◽  
Author(s):  
M. Rashid ◽  
S. Chen ◽  
L. E. Collins
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Tensile Testing ◽  
Standard Procedure ◽  
Large Diameter ◽  
Spring Back ◽  
Pipe Axis ◽  
Element Analysis ◽  
Line Pipe ◽  
Experimental Approaches

Tensile testing on large diameter line pipe is generally done using strap samples obtained in the transverse to pipe axis (TPA) orientation of a pipe. The strap samples are then flattened and machined prior to testing. Although the standardized tensile testing is well documented, the variability in the reported TPA tensile properties of the same material tested within a lab or at different labs has always been an issue. Recent work conducted at EVRAZ NA research lab has identified flattening as the main source of the variability in reported yield strength (YS) values for line pipe. The lack of a standard procedure for flattening TPA strap samples is a major obstacle to obtaining consistent results. Therefore, the main objective of this current study was to establish a standardized flattening procedure for TPA strap samples. Both finite element analysis (FEA) and experimental approaches were adopted. Various flattening methods and fixtures were studied. Extensive flattening experiments were conducted on TPA samples from different line pipe products. Results showed that the spring back after flattening in a TPA sample is different for pipes with different gauge and grades. It was established that consistent flattening can be achieved using appropriate fixtures for differerent ranges of tubular products defined by grade, diameter and gauges. Evaluation of the flattening fixture designs and experimental results are discussed in this paper.

Design of Ellipsoidal Heads Using Elastic-Plastic Finite Element Analysis

2002 ◽  
Author(s):  
Donald J. Florizone
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Vessel ◽  
Large Strain ◽  
Large Diameter ◽  
Spherical Shape ◽  
Element Analysis ◽  
Perfectly Plastic ◽  
Section Viii ◽  
Design Calculations

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.

Postliquefaction Deformation of Embankments and Effects on Restraining Piles

1998 ◽  
Vol 1633 (1) ◽  
pp. 19-25
Author(s):  
W.D. Liam Finn
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Residual Strength ◽  
Prestressed Concrete ◽  
Large Strain ◽  
Limit Equilibrium ◽  
Safety Evaluation ◽  
Equilibrium Analysis ◽  
Element Analysis ◽  
Seismic Safety

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.

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