scholarly journals Some comments on reinforced concrete structures forming column hinge mechanisms

Author(s):  
T. E. Kelly

Three buildings relying on column hinge mechanisms for post-elastic energy dissipation were studied using an inelastic dynamic computer program. The structures were an eight storey wall structure with ground storey columns, an eight storey frame with rigid, non-yielding beams, and a single storey frame with rigid, non-yielding beams. Parameters varied were earthquake input, design base shear and strain hardening ratio. All structures exhibited deformations far in excess of deflections under code static loading. The eight storey structures showed a tendency towards incremental collapse from P-delta effects when low, probably realistic, strain hardening ratios were used.

2021 ◽  
Vol 11 (2) ◽  
pp. 605
Author(s):  
Antonio Agresta ◽  
Nicola Cavalagli ◽  
Chiara Biscarini ◽  
Filippo Ubertini

The present work aims at understanding and modelling some key aspects of the sloshing phenomenon, related to the motion of water inside a container and its effects on the substructure. In particular, the attention is focused on the effects of bottom shapes (flat, sloped and circular) and water depth ratio on the natural sloshing frequencies and damping properties of the inner fluid. To this aim, a series of experimental tests has been carried out on tanks characterised by different bottom shapes installed over a sliding table equipped with a shear load cell for the measurement of the dynamic base shear force. The results are useful for optimising the geometric characteristics of the tank and the fluid mass in order to obtain enhanced energy dissipation performances by exploiting fluid–structure interaction effects.


1933 ◽  
Vol 1 (4) ◽  
pp. 151-155
Author(s):  
H. Hencky

Abstract The knowledge of the inelastic behavior of metals has experienced considerable growth in the last few years. To draw all the advantages possible from the experiments, frequently very difficult, an effort has been made to bring the entire development under some dominating physical ideas. These ideas are in fact very old, and deal mainly with the proper conception of the hidden elastic energy that is responsible for the statical component of the strain hardening. The analytical treatment of the inelastic behavior gives promise of being valuable not only in the testing of materials, but even for the designer of machines used in the forming of metals.


1994 ◽  
Vol 211-212 ◽  
pp. 233-236 ◽  
Author(s):  
F.A. Lewis ◽  
R.-A. McNicholl ◽  
A. Biscarini ◽  
B. Coluzzi ◽  
C. Costa ◽  
...  

1958 ◽  
Vol 25 (4) ◽  
pp. 529-536
Author(s):  
J. F. Besseling

Abstract Stress-strain relations are given for an initially isotropic material, which is macroscopically homogeneous, but inhomogeneous on a microscopic scale. An element of volume is considered to be composed of various portions, which can be represented by subelements showing secondary creep and isotropic work-hardening in plastic deformation. If the condition is imposed that all subelements of an element of volume are subjected to the same total strain, it is demonstrated that the inelastic stress-strain relations of the material show anisotropic strain-hardening, creep recovery, and primary and secondary creep due to the nonuniform energy dissipation in deformation of the sub-elements. Only quasi-static deformations under isothermal conditions are considered. The theory is restricted to small total strains.


2019 ◽  
Vol 6 (11) ◽  
pp. 181795 ◽  
Author(s):  
Shaojie Chen ◽  
Dawei Yin ◽  
Huimin Liu ◽  
Bing Chen ◽  
Ning Jiang

In the present study, uniaxial compression tests were conducted on sandstone–coal composite samples to investigate the effects of original macro-cracks in coal on the rockburst tendency. First, the energy dissipation theory was used to derive the elastic energy attenuation index of composite samples during uniaxial loading. Then, based on the test results obtained, the rockburst tendency of composite samples was evaluated and analysed using the uniaxial compressive strength and elastic energy attenuation index. The results show that the original macro-cracks in coal deteriorated the rockburst tendency of composite samples. The original horizontal cracks had the lowest effect on the rockburst tendency, whereas the vertical penetrating cracks through the coal centre (parallel to the loading direction) displayed the greatest effect. The mechanism by which these macro-cracks weakened the rockburst tendency involved two steps: (i) changing the physical properties and energy accumulation conditions of composite samples and (ii) increasing the energy dissipation of composite samples during uniaxial loading. These aspects are important to understand the rockburst hazards induced by the structural instability and failure of the composite system of coal seam and roof rock during deep coal mining.


2013 ◽  
Vol 479-480 ◽  
pp. 1170-1174
Author(s):  
Hee Cheul Kim ◽  
Dae Jin Kim ◽  
Min Sook Kim ◽  
Young Hak Lee

The purpose of this study was to evaluate seismic performance of rehabilitated beam-column joint using FRP sheets and Buckling Restrained Braces (BRBs) and provide test data related to rehabilitated beam-column joints in reinforced concrete structures. The seismic performance of total six beam-column specimens is evaluated under cyclic loadings in terms of shear strength, effective stiffness, energy dissipation and ductility. The test results showed wrapping FRP sheets can contribute to increase the effect of confinement and the crack delay. Also retrofitting buckling restrained braces (BRBs) can improve the stiffness and energy dissipation capacity. Both FRP sheets and BRBs can effectively improve the strength, stiffness and ductility of seismically deficient beam-column joints.


2017 ◽  
Vol 873 ◽  
pp. 259-263
Author(s):  
Hao Zhang ◽  
Zi Hang Zhang ◽  
Yong Qiang Li

The dynamic behavior of the prefabricated and cast in situ concrete shear wall structures subjected to seismic loading is investigated by finite element method. This paper adopted a prefabricated concrete shear wall in a practical engineering. The Precise finite element models of prefabricated and cast in situ concrete shear wall were established respectively by ABAQUS. The damaged plasticity model of concrete and kinematic hardening model of reinforcing steel were used. The top displacement, top acceleration, story drift ratio and base shear forceof prefabricated and cast in situ concrete shear wall under different seismic excitation were compared and analyzed. The earthquake resistant behaviorsof the two kinds of structuresare analyzed and compared. Results show that the performances of PC structure were equal to the cast-in-situ ones.


2019 ◽  
Vol 6 (4) ◽  
pp. 181965 ◽  
Author(s):  
Jia Suizi ◽  
Cao Wanlin ◽  
Liu Zibin

This study developed a low-energy consumption composite wall structure constructed with a pre-fabricated lightweight steel frame that is suitable for houses in villages and towns and evaluated its anti-seismic performance. A low-reversed cyclic-loading test was conducted on four full-scale pre-fabricated structure specimens, including a lightweight, concrete-filled steel tube (CFST) column frame specimen (abbreviated as SFCF), a lightweight CFST column frame composite wall specimen (abbreviated as SFCFW), an H-steel column frame specimen (abbreviated as HSCF) and an H-steel column frame composite wall specimen (abbreviated as HSCFW). The failure characteristics, hysteretic behaviour, strength, rigidity, ductility and energy dissipation capacity of each specimen were compared and analysed. The results demonstrated that the pre-fabricated, double L-shaped beam–column joint with a stiffener rib which was proposed in this study worked reliably and exhibited good anti-seismic performance. The yield, ultimate and frame yield loads of the specimen SFCFW were 1.72, 1.80 and 2.03 times higher than those of specimen SFCF. The yield load, ultimate load and frame yield loads of specimen HSCFW were 1.27, 1.68 and 1.82 times higher than those of specimen HSCF. This indicates that the embedded composite wall contributed significantly to the horizontal bearing capacities of the SFCF and HSCF specimens. The embedded composite wall was divided into multiple strip-shaped composite panels during failure and achieved a stable support for the frame in the later stages of elastoplastic deformation. The horizontal strips of the tongue-and-groove connection between the strip-shaped composite panels produced reciprocating bite displacements, and ultimately improved the structure's energy dissipation capacity significantly.


2014 ◽  
Vol 11 (6) ◽  
pp. 589-596
Author(s):  
Valesyan Shant

The effect of ageing on the dissipative properties of getinacks subjected to repeated static loading has been investigated. Specimens were tested at the age of 1, 4, and 8 years. The approximation of experimental data is done, and the energy of dissipation is calculated. Based on the investigation of getinacks manufactured by the technology of regulated thermo-pressing, this technology can be recommended for the manufacturing of appropriate products.The results of experimental investigation of the effect of temperature field on the dissipative properties of layered getinacks widely applicable in electrical manufacturing, electronics and microelectronics are considered in this paper. The approximation of the experimentally obtained dependences between σ and ε for the loading (→) and unloading (←) parts of the hysteresis loop are calculated and plotted. The factor of energy dissipation is defined. Estimated that the temperature field affects the dissipative properties of the layered getinacks and that effect is depending on the value of applied load cyclically acting on the material.


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