scholarly journals STUDY OF THE PLASTIC HINGE POSITION OF BURIED STEEL PIPE ON FAULT DISPLACEMENT

2016 ◽  
Vol 72 (4) ◽  
pp. I_161-I_166 ◽  
Author(s):  
Nobuhiro HASEGAWA ◽  
Junji KIYONO
Keyword(s):  
Plastic Hinge ◽  
Steel Pipe ◽  
Hinge Position ◽  
Fault Displacement

Change of Plastic Hinge Position in Radial Ring Rolling without Guide-Roll

2010 ◽  
Vol 42 ◽  
pp. 30-34
Author(s):  
Yong Xing Hao ◽  
Su Juan Shi ◽  
Lv Yun Yang ◽  
Song Wei Yang
Keyword(s):  
Wall Thickness ◽  
Plastic Hinge ◽  
Position Angle ◽  
Rolling Process ◽  
Ring Rolling ◽  
Thickness Change ◽  
Plastic Deformation Process ◽  
Hinge Position ◽  
Ring Rolling Process ◽  
Rolling Deformation

Radial ring rolling is an unsteady plastic deformation process. Internal stress of the ring is foundation of formation of the plastic hinge. The radial wall thickness of ring changes gradually along ring circumferential direction. Theoretical analysis and FE simulation show that: the plastic hinge is not always exactly opposite to the rolling deformation zone in ring rolling process without guide-roll. The plastic hinge position angle β0 is affected by ratio of rolling entrance wall thickness H0 and rate of wall thickness change η. Curve of β0-H0/η is shaped as double U staggered relative to each other. With the H0/η increasing, β0 reduces gradually and approaches to π in the range of H0/η>6.28. H0/η>14.6H0/R2. Only when the rolling process is steady, and H0≈R2, β0 is greater than π, and approximates to π. The β0 fluctuates dramatically when H0/η≈5.71. In some cases, H0/η may fluctuate in 0 to 6.28, leading to the instability of plastic hinge position.

scholarly journals Analysis on Fracture Behavior and Optimization of Beam-Column Connections with Expanded Flanges of Steel Frames

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hongwei Ma ◽  
Zhen Zhang ◽  
Kun Wang ◽  
Yan Liu ◽  
Kai Guo ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Plastic Hinge ◽  
Steel Frames ◽  
Stress Triaxiality ◽  
Simulation Models ◽  
Equivalent Strain ◽  
Evaluation Index ◽  
Hinge Position ◽  
Energy Dissipation Capacity ◽  
Plastic Equivalent Strain

In this study, the parameters of concave expanded flanges of beam-column connections of steel frames are optimized based on the effects of different sizes of concave expanded flanges on the fracture performance. Firstly, two beam-column connection models with concave expanded flanges are built and analyzed under cyclic loads, which have the same conditions as the specimens during the previous test. Secondly, the validity of the numerical simulation models is verified through analyzing the hysteretic behaviors of the connections with concave expanded flanges, such as the plastic hinge position, the hysteresis curves, the skeleton curves, the stiffness degradation, the ductility coefficient, and the energy dissipation capacity. Thirdly, in order to comprehensively evaluate the fracture status of metal materials, the relevant fracture evaluation index (the stress triaxiality ratio (Rσ), plastic equivalent strain index (PI), and cracking index (RI)) are introduced. Afterwards, eighteen numerical simulation models with differences in the length la of the reinforced section, the length lb of the transition section, and the width c of the reinforced section were analyzed. Finally, the parameters of the concave expanded flanges of the beam-column connections are optimized based on the results of the three fracture evaluation index.

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