ON CREEP STRAIN OBSERVATION OF PRESTRESSED CONCRETE STATICALLY INDETERMINATE FRAME STRUCTURE CASTED IN SITE AND ITS CREEP STRESS AND STRAIN ANALYSIS

1994 ◽  
Vol 59 (459) ◽  
pp. 131-141
Author(s):  
Seiichi WATANABE
Keyword(s):  
Creep Strain ◽  
Prestressed Concrete ◽  
Strain Analysis ◽  
Frame Structure ◽  
Stress And Strain ◽  
Creep Stress

Creep Stress Analyses Affected by Defect Geometries on P91 Pipe With Local Wall Thinning Under High Temperature

2010 ◽  
Author(s):  
Jilin Xue ◽  
Changyu Zhou ◽  
Jian Peng
Keyword(s):  
High Temperature ◽  
Creep Strain ◽  
Power Plants ◽  
Creep Condition ◽  
Service Condition ◽  
Stress And Strain ◽  
Steel Pipes ◽  
Creep Stress ◽  
Wall Thinning ◽  
Local Wall Thinning

P91 heat-resistant steel pipes are widely used at high temperature in power plants and nuclear power plants. The service condition and manufacturing process may produce defects of local wall thinning, which may result in stress redistribution of the pipes during the service process at elevated temperature. For the purpose of understanding the creep stress and strain accumulation affected by local wall thinning geometries under creep condition, three groups of models were calculated, using three-dimensional models based on finite element analyses (FEA) codes ABAQUS. In this study, monotonic internal pressure was conducted on P91 full-scale steel pipes at 625°C, with local wall thinning located at the inner surface. Then, the creep strain and stress of pipes after 100,000h could be obtained corresponding to different models. Based on the analysis, the figures of creep stress and strain varying with defect geometries were plotted. Then, the stress and strain of pipes with local wall thinning affected by defect geometries, including different defect depths, different defect axial lengths and different defect hoop angles, were discussed. The results indicate that creep stress and creep strain increase with defect geometries. The variation laws have been summarized. The research results can provide the possibility on safety assessment and structure integrity analysis of the pipe with local wall thinning at high temperature effectively.

Creep Stress Analyses Affected by Load Properties on P91 Pipe with Local Wall Thinning under High Temperature

2011 ◽  
Vol 704-705 ◽  
pp. 1304-1309
Author(s):  
Ji Lin Xue ◽  
Chang Yu Zhou ◽  
Jian Peng
Keyword(s):  
High Temperature ◽  
Internal Pressure ◽  
Creep Strain ◽  
Power Plants ◽  
Creep Condition ◽  
Stress Redistribution ◽  
Stress And Strain ◽  
Creep Stress ◽  
Wall Thinning ◽  
Local Wall Thinning

The local wall thinning defect is very normal on pipes in power plants, which may result in stress redistribution of the pipes during the service process at elevated temperature. For the purpose of understanding the stress redistribution and strain accumulation of pipes with local wall thinning affected by load properties under creep condition, three groups of models were calculated, using three-dimensional elastic-plastic finite element analyses (FEA) based on FEA codes ABAQUS. In this study, the pipes has an identical defect of local wall thinning, the load properties and values are changed. Three groups of load properties, considering here, were monotonic internal pressure, monotonic moment and both internal pressure and moment, respectively. The numerical simulation conducted on P91 full-scale steel pipes at 625°C, with local wall thinning located at the inner surface. Then, von Mises stress and creep strain of pipes after 100,000h could be obtained corresponding to different models. Based on the analysis, the figures of creep stress and strain varying with load properties were plotted. Then, the stress and strain of pipes with local wall thinning affected by load properties were discussed. The results indicate that creep stress and creep strain increase with load properties. The variation laws have been summarized. The research results can provide the possibility on safety assessment and structure integrity analysis of the pipe with local wall thinning at high temperature effectively.

scholarly journals Experimental Study of a New Precast Prestressed Concrete Joint

2018 ◽  
Vol 8 (10) ◽  
pp. 1871 ◽  
Author(s):  
Xueyuan Yan ◽  
Suguo Wang ◽  
Canling Huang ◽  
Ai Qi ◽  
Chao Hong
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Prestressed Concrete ◽  
Precast Concrete ◽  
Concrete Strength ◽  
Frame Structure ◽  
Loading Test ◽  
Concrete Frame ◽  
Concrete Joints ◽  
Precast Prestressed Concrete

Precast monolithic structures are increasingly applied in construction. Such a structure has a performance somewhere between that of a pure precast structure and that of a cast-in-place structure. A precast concrete frame structure is one of the most common prefabricated structural systems. The post-pouring joint is important for controlling the seismic performance of the entire precast monolithic frame structure. This paper investigated the joints of a precast prestressed concrete frame structure. A reversed cyclic loading test was carried out on two precast prestressed concrete beam–column joints that were fabricated with two different concrete strengths in the keyway area. This testing was also performed on a cast-in-place reinforced concrete joint for comparison. The phenomena such as joint crack development, yielding, and ultimate damage were observed, and the seismic performance of the proposed precast prestressed concrete joint was determined. The results showed that the precast prestressed concrete joint and the cast-in-place joint had a similar failure mode. The stiffness, bearing capacity, ductility, and energy dissipation were comparable. The hysteresis curves were full and showed that the joints had good energy dissipation. The presence of prestressing tendons limited the development of cracks in the precast beams. The concrete strength of the keyway area had little effect on the seismic performance of the precast prestressed concrete joints. The precast prestressed concrete joints had a seismic performance that was comparable to the equivalent monolithic system.

scholarly journals Stress and strain analysis from dynamic loads of mechanical hand using finite element method

2018 ◽  
Vol 352 ◽  
pp. 012017 ◽  
Author(s):  
Iskandar Hasanuddin ◽  
Husaini ◽  
M. Syahril Anwar ◽  
B.Z. Sandy Yudha ◽  
Hasan Akhyar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain Analysis ◽  
Dynamic Loads ◽  
Stress And Strain ◽  
Mechanical Hand ◽  
Element Method

Constitutive inequalities for isotropic elastic solids under finite strain

1970 ◽  
Vol 314 (1519) ◽  
pp. 457-472 ◽  
Keyword(s):  
Scalar Product ◽  
Finite Strain ◽  
Strain Analysis ◽  
Stress And Strain ◽  
Elastic Solids ◽  
Intrinsic Interest ◽  
Typical Member ◽  
Rates Of Change ◽  
Constitutive Inequalities ◽  
Strain Measures

Possible restrictions on isotropic constitutive laws for finitely deformed elastic solids are examined from the standpoint of Hill (1968). This introduced the notion of conjugate pairs of stress and strain measures, whereby families of contending inequalities can be generated. A typical member inequality stipulates that the scalar product of the rates of change of certain conjugate variables is positive in all circumstances. Interrelations between the various inequalities are explored, and some statical implications are established. The discussion depends on several ancillary theorems which are apparently new; these have, in addition, an intrinsic interest in the broad field of basic stress—strain analysis.

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