Failure Mode of ED and AD Type Head Plates Subject to Convex Side Pressure

2017 ◽  
Author(s):  
Hiroki Yada ◽  
Masanori Ando ◽  
Kazuyuki Tsukimori ◽  
Masakazu Ichimiya ◽  
Yoshinari Anoda
Keyword(s):  
Failure Mode ◽  
Convex Side ◽  
Bending Deformation ◽  
Containment Vessel ◽  
Side Pressure ◽  
Safety Margins ◽  
Bending Radius ◽  
Pressure Failure ◽  
The Relationship ◽  
Inside Out

Containment vessel is an important structure to prevent a significant and sudden radioactive release, however, the safety margin of the containment vessel against the internal or external pressure are not numerically clarified. Namely, the safety margins due to the relationship of the ultimate toughness of containment vessel structures and maximum design pressure is not clear. Indeed, to clarify the progress of events under the beyond design basis events (BDBE) and to design the BDBE countermeasure equipment, it is necessary to evaluate the pressure toughness of containment vessel adequately. The containment vessel of fast reactor is composed of the various structures. The head plate that composes the boundary between primary and secondary coolant in intermediate heat exchanger has an important role when the progress of the BDBE is considered. Therefore, in order to develop the evaluation method of the pressure toughness of the head plate under the BDBE, the pressure failure tests and finite element analysis of head plate structure subjected to convex side pressure was performed in this study. Two types of head plates were applied for pressure failure tests. ED type and AD type head plates were chosen as a representative to clarify the effect of shape. These head plates have 250mm diameter and 3mm thickness. The head plates were subjected to pressure on convex side by water in the pressure failure tests. In tests, almost completely inside-out of each head plate was caused after buckling. Then after that, leakage was observed near the rim. Two types of head plates had similar failure mode in spite of difference original shapes. The circumferential through-wall crack was observed near the rim of each head plates. According to the results of pressure failure tests, it is seemed that the circumferential crack was caused by straightening following bending associated with large deformation as inside-out. To clarify the relationship between bending radius and crack initiation, straightening following the bending deformation (bending-straightening) tests were performed. As a result, the crack was initiated in the test case of the bending radius smaller than 3 mm. 3 mm of bending radius generate 33 % strain. The bending radius at the time of leakage observed of head plates was estimated almost similar value at which crack initiated. Therefore, it can be concluded that a failure mode of a head plate subjected convex side pressure is circumferential through-wall crack caused by straightening following bending deformation near the rim.

Experimental Study on Ultimate Strength of a Ellipsoidal Dished Head Plate Under Pressure on Convex Surface

2016 ◽  
Author(s):  
Hiroki Yada ◽  
Masanori Ando ◽  
Kazuyuki Tsukimori ◽  
Masakazu Ichimiya ◽  
Yoshinari Anoda
Keyword(s):  
Evaluation Method ◽  
Convex Surface ◽  
Safety Margin ◽  
Fem Analysis ◽  
External Pressure ◽  
Containment Vessel ◽  
Side Pressure ◽  
Safety Margins ◽  
Intermediate Heat Exchanger ◽  
Radioactive Release

Containment vessel is an important structure to prevent a significant and sudden radioactive release, however, the safety margin of the containment vessel against the internal or external pressure are not numerically clarified. Namely, the safety margins due to the relationship of the ultimate toughness of containment vessel structures and maximum design pressure is not clear. Indeed, to clarify the progress of events under the beyond design basis events (BDBE) and to design the BDBE countermeasure equipment, it is necessary to evaluate the pressure toughness of containment vessel adequately. The containment vessel of fast reactor is composed of the various structures. The head plate that forms the boundary between primary and secondary coolant in intermediate heat exchanger has an important role when the progress of the BDBE is considered. In this study, in order to develop the evaluation method of the pressure toughness of the head plate under the BDBE, the ultimate pressure test of the head plate test specimen subjected to convex side pressure was performed, and also FEM analysis was performed for discussion.

Effect of 3-D Initial Imperfections on the Deformation Behaviors of Head Plates Subjected to Convex Side Pressure

2018 ◽  
Author(s):  
Hiroki Yada ◽  
Masanori Ando ◽  
Kazuyuki Tsukimori ◽  
Masakazu Ichimiya ◽  
Yoshinari Anoda
Keyword(s):  
Finite Element ◽  
Power Plants ◽  
Evaluation Method ◽  
Safety Margin ◽  
External Pressure ◽  
Convex Side ◽  
Element Analysis ◽  
Containment Vessel ◽  
Side Pressure ◽  
Post Buckling

Containment vessel (CV) of nuclear power plants is an important structure to prevent a significant and sudden radioactive release, however, the safety margin of the containment vessel against the internal or external pressure are not numerically clarified. The head plate is one of the components which constitute the CV boundary. In order to develop the evaluation method of the pressure toughness of the head plate at beyond design basis events, the pressure failure tests and finite element analysis of the head plates subjected to convex side pressure were performed. In the tests, non-axisymmetric deformations with local deformation concentration were observed in post buckling behavior in the case of the thin thickness head plate. In this study, to evaluate these non-axisymmetric deformations in the test, finite element analyses using detailed 3-D solid model constructed by precise dimensions of the head plates measured by 3-D scanner were performed. Moreover, FEA using simplified model with uniform or non-uniform thickness model were performed. Through a series of FEA, it was clarified the effect of each thickness pattern on post buckling non-axisymmetric deformation.

Machining Deformation Equation of FWP Based on Rayleigh-Leeds Method

2012 ◽  
Vol 562-564 ◽  
pp. 917-920
Author(s):  
Yao Hua Deng ◽  
Gui Xiong Liu
Keyword(s):  
Energy Conditions ◽  
Test Function ◽  
Bending Deformation ◽  
Flexible Workpiece ◽  
Deformation Equation ◽  
Flexible Part ◽  
Minimum Potential ◽  
Deformation Test ◽  
Function Finding ◽  
The Relationship

This paper discusses the FWP bending deformation processing computing problems. Using Rayleigh-Leeds method to solve the flexible part bending deformation. Designing flexible part bending deformation test function. Finding out the flexible part itself material characteristics, the relationship between Fz and deformation through satisfying FWP processing process of a flexible minimum potential energy conditions to work out the approximate solution of the flexible part bending deformation. Finally, think a rectangular flexible workpiece that made of polyurethane sponge as an experiment subject. The results show that the calculated results of the average of the relative deviation are only 6.85%. Proof that this bending deformation test functions satisfies the actual deformation calculation requirements.

Influence Parameters Analysis of Forming Quality and System Dynamics Simulation of Vertical Steel Bar Benting

2013 ◽  
Vol 483 ◽  
pp. 280-284
Author(s):  
Xi Jian Zheng ◽  
Xin Zhuo Wang ◽  
Jin Meng Zhang ◽  
Yu Fei Zhu
Keyword(s):  
Simulation Analysis ◽  
Reference Value ◽  
Dynamics Simulation ◽  
Forming Quality ◽  
Steel Bar ◽  
New Process ◽  
Cutting Length ◽  
Bending Radius ◽  
The Relationship

The vertical steel bar bending forming is a kind of new process of bending method. The bending speed, bending radius and clamping length H which is the parameters of vertical steel bar bending machine , is directly affect the quality of bending forming parts. This paper calculated the length of reinforcement before being incised and the springback angle of bending steel bar which obtained the reasonable cutting length and bending Angle; Then based on rigid-flexible virtual prototype technology to build the dynamics model of vertical steel bar bending system. Through simulation analysis ,it obtained the relationship between bending speed, bending radius , clamping length H and forming quality of bending steel bar. In this paper, the analysis method have reference value to the design of similar steel bar bending machines.

Association of Wall Stress of Human Intracranial Saccular Aneurysm With Coil Packing Density After Coil Embolization

2012 ◽  
Author(s):  
Joseph E. Pichamuthu ◽  
Alkiviadis Tsamis ◽  
Brian T. Jankowitz ◽  
David A. Vorp
Keyword(s):  
Coil Embolization ◽  
Intracranial Aneurysms ◽  
Cerebral Arteries ◽  
Wall Stress ◽  
Surgical Clipping ◽  
Risk Of Rupture ◽  
Relationship Of ◽  
The Relationship ◽  
Inside Out ◽  
Metallic Coils

Coil embolization has become a widely accepted endovascular procedure for intracranial aneurysms, as an alternative to surgical clipping [1,2]. This procedure involves treating an aneurysm from the inside out, whereby metallic coils are placed into the aneurysm to induce thrombosis of the lumen and eliminate the risk of rupture and hemorrhage. Successful endosaccular packing mainly depends on the morphological features and size of the aneurysm, and the relationship of the aneurysm to the cerebral arteries.

Experimental Study on the Shear Capacity of Rabbet Cast-in-Place Prefabricated Beam

2020 ◽  
Vol 980 ◽  
pp. 266-274
Author(s):  
Jian Hua Xiao ◽  
Miao Liu ◽  
Jin Li Wang ◽  
Abdulhamid Yakubu Anvah
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Concrete Beam ◽  
Joint Stiffness ◽  
Load Level ◽  
Shear Capacity ◽  
Oblique Section ◽  
Shear Bearing Capacity ◽  
The Relationship

In order to investigate the shear capacity of prefabricated beam, experiments about shear bearing were performed on one integral pouring contrast beam and two prefabrication and assembly beams. Inspecting the relationship between load and deflection under the load, the development regularity of strain between longitude reinforced and stirrup, the shear capacity of cracking load and ultimate bearing capacity, analyzing failure mode of oblique section and connection performance of old and new concrete in the groove, and compared with the mechanical properties of cast-in-place concrete beam. The experimental results indicate that: prefabrication and assembly beam and cast-in-place beams have similar shear bearing capacity and failure mode of oblique section, along with the load level continues to increase, the groove joint stiffness weakened, but has little effect on the overall deformation.

An Approach for Performance-Based Capacity Assessment of Prestressed Concrete Containment Vessels for Internal Accidents Application to VVER 1000 Containment Vessel

2010 ◽  
Vol 5 (4) ◽  
pp. 452-462 ◽  
Author(s):  
Anton Andonov ◽  
◽  
Dimitar Stefanov ◽  
Marin Kostov
Keyword(s):  
Failure Mode ◽  
Prestressed Concrete ◽  
Structural Integrity ◽  
Damage Index ◽  
Capacity Assessment ◽  
Assessment Procedure ◽  
Performance Levels ◽  
Containment Vessel ◽  
Leak Tightness ◽  
Load Intensity

A direct procedure is proposed for capacity assessment of prestressed concrete containment structures subjected to internal accident loads. The assessment procedure is based on graphical comparison between the structural capacity and the load intensity by plotting both parameters in the same “temperature gradient – overpressure” coordinate system. Furthermore, the capacity in terms of structural integrity and leak tightness is evaluated, corresponding to different limit states or performance levels. A new damage index is proposed in order to correlate the intensity of damages on the containment structure with the load intensity. The criteria for leak tightness and structural integrity are adopted for VVER-1000 containment structure. The ultimate pressure capacity, the failure mode and the capacity corresponding to different performance levels of the containment structure are assessed. The influence of the temperature load on the structure response is also studied. Conclusions are drawn on the VVER-1000 containment vessel overpressure capacity and its response to different design basis and severe accidents. The main failure mode and the critical zones of the structure are also determined.

A Correlation Model Based Failure Mode Analysis Method for Mechatronics Systems

2015 ◽  
Vol 727-728 ◽  
pp. 637-640
Author(s):  
Ying Liu ◽  
Zheng Hu ◽  
Shi Gang Zhang
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Cognitive Map ◽  
Fuzzy Cognitive Map ◽  
Mode Analysis ◽  
Correlation Model ◽  
Analysis Method ◽  
Failure Mode Analysis ◽  
The Relationship ◽  
Reasoning Technique

Failure mode analysis formechatronics systems has many problems in real applications in terms of excessivedependency on experience, lack of uniform description and tedious analysis work. In order to increaseits effectiveness, an automatic failure modes analysis framework is constructedand an extended fuzzy cognitive map is used as a reasoning technique toanalysis the effect of the failures. A function-failure correlation model witha standard description is adopted to describe the relationship between failuremodes and functions, so that designers and engineers from different fields cancomprehend and communicate within the same framework. Functional flows andfailure modes are defined as basic concepts in the fuzzy cognitive map, whichprovides an easy way to carry out an automatic cause and effect reasoning.

Effect of grain angle on shear strength of Douglas-fir wood

Holzforschung ◽  
2012 ◽  
Vol 66 (5) ◽  
pp. 655-658 ◽  
Author(s):  
Rakesh Gupta ◽  
Arijit Sinha
Keyword(s):  
Shear Strength ◽  
Root Mean Square ◽  
Failure Mode ◽  
Shear Plane ◽  
Douglas Fir ◽  
Mean Square ◽  
Rolling Shear ◽  
Grain Angle ◽  
Shear Block ◽  
The Relationship

Abstract The effect of grain angle (GA) on shear strength of Douglas-fir has been evaluated. Shear block specimens with a GA varying from 0 to 90° was loaded in the shear plane, resulting in failure mode transitioning from parallel to grain shear to rolling shear. As expected, shear strength decreased as the GA increased from 0° to 90°. A root-mean-square equation was found to be suitable to predict the relationship between GA and shear strength. Traditional Hankinson formula and the Tsai-Wu criteria were less effective with this regard.

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