scholarly journals THE ELASTOPLASTIC CALCULATION OF FRAMES USING THE DISPLACEMENT METHOD

2019 ◽  
Vol 15 (3) ◽  
pp. 120-130
Author(s):  
Alexander Potapov
Keyword(s):  
Lower Boundary ◽  
Displacement Method ◽  
Margin Of Error ◽  
Limiting Load ◽  
Plastic Stage ◽  
Plastic Zones ◽  
Two Stages ◽  
Previous Loading ◽  
Incremental Equations ◽  
Elastic Stage

We proposed a method for calculating statical indeterminacy frames taking into account plastic defor­mations, which is based on the use of a schematized diagram of material with hardening. Two types of standard beams with supports are used during the implementation of the displacement method (DM) and the elastic solu­tion of the problem: “fixed” - “pinned” and “fixed” - “fixed”, but unlike the elastic solution, standard beams con­tain plastic zones (PZs). So as the stresses in these zones did not exceed the limit of yielding in the nonlinear frame calculation, we took measures to transform the PZs into equal strength plastic zones (ESPZ). The calcula­tions were made for both types of beams for all single and load impacts. The frame calculation consists of two stages (elastic and plastic). At the elastic stage, we determine an elastic moment diagram and the corresponding load. For a practical use of the DM in a nonlinear frame calculation, we introduced a simplifying prerequisite sup­plementing the well-known hypotheses of the classical version of the method, and formulated a Statement of the limiting load. According to the Statement, each length of the PZ can correspond to the lower boundary of the lim­iting load. The plastic stage of the calculation is performed at a given length of the PZ using the method of se­quential loadings. At each loading stage, incremental equations are written using the DM equations, which estab­lish relations between incremental moments and the incremental load, that allows you to get the resulting moment diagram. This diagram represents a sum of the elastic diagram and the diagrams of incremental moments at all previous loading stages. According to the resulting diagram, we calculate the length of the PZ, together with the limiting load. The calculation is considered complete if the length of the PZ does not exceed the specified value within the margin of error.

Nonlinear Analysis of Steel and Concrete Composite Beams Strengthened with Prestressed FRP Bars

2012 ◽  
Vol 256-259 ◽  
pp. 775-778
Author(s):  
Jia Yang
Keyword(s):  
Nonlinear Analysis ◽  
Composite Beam ◽  
Composite Beams ◽  
Deformation Curve ◽  
Shear Connectors ◽  
Plastic Stage ◽  
The Moment ◽  
Analysis Mode ◽  
Frp Bars ◽  
Elastic Stage

Steel and concrete composite beam is a kind of composite beam which the steel and the concrete are connected by shear connectors. Now, many experts and scholars have carried out many experimental research and theoretical analysis about it. But, steel and concrete composite beams strengthened with prestressed FRP bars have not been studied. Based on the structure, the nonlinear analysis mode of steel and concrete composite beams strengthened with prestressed FRP bars is proposed, the calculating program is researched. The relationships between moment and curvature, also between load and deformation of steel and concrete composite beams strengthened with prestressed FRP bars are obtained. The results show that the moment-curvature curve and load-deformation curve of steel and concrete composite beams strengthened with prestressed FRP bars can be separated to elastic stage, elastic-plastic stage and plastic stage.

scholarly journals Transition zone in Bearing Capacity Problem from Plasticity Method, Discrete Element Method and Laboratory tests

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Yungming Cheng
Keyword(s):  
Discrete Element Method ◽  
Bearing Capacity ◽  
Transition Zone ◽  
Laboratory Tests ◽  
Friction Angle ◽  
Discrete Element ◽  
Element Approach ◽  
Plastic Stage ◽  
Elastic Stage ◽  
The Continuum

<p>In this paper, the classical bearing capacity problem and the logspiral transition zone are re-considered from a continuum plasticity approach as well as discrete element approach. In the discrete element approach, the bearing capacity problem is considered from the elastic stage, plastic stage to the final rupture stage. It is found that there are noticeable differences in the failure mechanism between the continuum and discontinuum analyses, and the well-known logspiral transition zone is also not apparent in both the discrete element approach, plasticity approach as well as the laboratory tests. With the increase in the friction angle of soil, the transition zone is becoming more like a wedge zone than a logspiral zone as found from the present study. </p>

Elastic Rebound of a Blast Door Under Explosion Loadings

2018 ◽  
Vol 18 (10) ◽  
pp. 1871011
Author(s):  
Qiushi Yan ◽  
Dong Guo
Keyword(s):  
Aspect Ratio ◽  
Shear Force ◽  
Plastic Range ◽  
Dynamic Shear ◽  
Load Duration ◽  
Rebound Effects ◽  
Elastic Rebound ◽  
Conventional Weapons ◽  
Plastic Stage ◽  
Elastic Stage

Rebound effects can be caused for a blast door under explosion loadings of conventional weapons. Such effects reaching a certain extent can lead to severe reversed stresses and even destroy the hinge and lock system before the door leaf. In this study, an analytical model for the elastic rebound of a blast door under explosion loadings was proposed and analyzed. Based on the calculations, the effects of aspect ratio and load duration on the rebound behavior were analyzed. Furthermore, for extension of the analysis from the elastic to plastic range, comparison of the solutions with the analytical ones was made. The results showed that the positive and negative dynamic shear force peaks of the blast door deceased gradually with the aspect ratio, whereas the rebound strength was inversely proportional to the load duration. For blast doors entering into the plastic stage, the rebound behavior was similar to the elastic stage, implying that the design of a blast door can be based on its characteristics in elastic stage.

Flexural Behavior of Concrete-Filled FRP-Steel Composite Circular Tubes

2011 ◽  
Vol 243-249 ◽  
pp. 1316-1320 ◽  
Author(s):  
Yang Wei ◽  
Gang Wu ◽  
Zhi Shen Wu ◽  
Dong Sheng Gu
Keyword(s):  
Large Scale ◽  
Failure Modes ◽  
Concrete Beams ◽  
Steel Tube ◽  
Flexural Behavior ◽  
Composite Tube ◽  
Circular Tubes ◽  
Steel Composite ◽  
Plastic Stage ◽  
Elastic Stage

Three large-scale concrete-filled FRP-steel composite circular tubes and a control steel tube were tested to investigate flexural behavior. The effects of FRP and composite with different types of FRP with various ultimate strains were investigated. The study demonstrated the important effect of FRP, and showed that the load-displacement curves of FRP-steel composite tube beams could be divided into four stages: elastic stage, plastic stage, hardening stage and residual stage. An additional decline stage was gained for multi-fiber with different ultimate strains and steel composite tube concrete beams. FRP could increase the ultimate bearing capacity and bring the hardening stage after steel tube yielding, and a certain degree of stiffness would be achieved to avoid the “zero stiffness”. The composite of a variety of FRP could relax fracture failure for the FRP-steel composite steel concrete beams, realized the successive rupture of fiber in batches and changed the failure modes.

Performance Comparison of Beams with Different Stirrups

2012 ◽  
Vol 598 ◽  
pp. 539-542
Author(s):  
Hai Tao Wan ◽  
Li Li
Keyword(s):  
Bearing Capacity ◽  
High Strength ◽  
Performance Comparison ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Practical Application ◽  
Loading Test ◽  
Plastic Stage ◽  
Elastic Stage ◽  
Better Than

High strength concrete and high strength reinforcement technology have been quite mature,but there are still less in practical application of china.CRB550 grade reinforcement is formed by HPB235 reinforcement through cold-working, which strength is much improved,but ductility did not change much. 6 reinforced concrete beams with different stirrups are designed for low cyclic loading test. Contrasting the test results, in the elastic stage, beam with CRB550 stirrups and beam with HPB235 stirrups is very similar in bearing capacity and deformation performance.However, in the elastic-plastic stage, beam with CRB550 stirrups in bearing capacity and deformation performance is better than beam with HPB235 stirrups.Therefore, it is proved that CRB550 reinforcement can replace HPB235 reinforcement as stirrups in RC beams.

A proposed nomenclature for stages and series for the Cambrian of Laurentia

1998 ◽  
Vol 35 (4) ◽  
pp. 323-328 ◽  
Author(s):  
A R Palmer
Keyword(s):  
Lower Boundary ◽  
Extinction Events ◽  
Two Stages

An internally consistent succession of six named regional stages (from youngest to oldest: Sunwaptan, Steptoean, Marjuman, Delamaran, Dyeran, Montezuman), with their boundaries defined by regional extinction events within the trilobite record, is proposed for the trilobite-bearing rocks of Laurentia. Sub-trilobite stage(s) are recommended but unnamed. The three youngest stages have been named previously, but the lower boundary of the Marjuman is shifted downward. The three older stages within the trilobite record are new. If deemed necessary, four regional series are also suggested (from youngest to oldest: Millardan, Lincolnian, Waucoban, and Begadean); each of the three youngest series accommodates two stages.

Elastic-Plastic Impact Loads of Steel Spheres Impacting on Planes

2010 ◽  
Vol 43 ◽  
pp. 666-669 ◽  
Author(s):  
Yu Liu ◽  
Chang Long Du ◽  
Jia Jia Zhang ◽  
Hao Jiang
Keyword(s):  
Material Properties ◽  
Fundamental Problem ◽  
Element Model ◽  
Impact Loads ◽  
Plastic Deformations ◽  
Plastic Stage ◽  
Simulation Results ◽  
The Impact ◽  
The Finite Element Model ◽  
Elastic Stage

The impact between spheres and planes was a fundamental problem in the objects impacts. The impact loads were investigated for the different materials spheres impacting on the different materials planes in this paper. The results of the impact between two elastic materials were consistent with the Hertz results, which indicated that the finite element model was accurate and reliable. The simulation results showed that the impact loads would decrease if there were plastic deformations during the impact. For the same material properties of the plane and the sphere, the impact loads of the plane were higher than ones of the sphere. In other words, the impact between the same materials made the plane prone to fail. If the material properties of the plane and the sphere were different, the impact loads and deformations were depended on the ratio of the contact stress and the yield limit. The material in elastic stage had the lower impact loads compared with one in plastic stage. The material with plastic deformations would keep some residual stress and offset after the contact.

Study on the Seismic Behavior of Hollow R.C Shear Wall Model Building with and without Seams

2010 ◽  
Vol 163-167 ◽  
pp. 1480-1484
Author(s):  
Gang Wang ◽  
Xiao Hu ◽  
Qiong Mei Wang ◽  
Yong Tao Gao
Keyword(s):  
Seismic Behavior ◽  
Model Building ◽  
Shear Walls ◽  
Shear Wall ◽  
Wall Structure ◽  
Wall Model ◽  
High Rise ◽  
Deformation Feature ◽  
Plastic Stage ◽  
Elastic Stage

Based on the pseudo-dynamic and pseudo-static under low-cycle test of 10-storey model building without seams and 6-storey model building with seams, the change of dynamic characteristics, the failure mechanism, the deformation feature and ductility of two type structures are discussed. The result of experimental study proves that the capacity of hollow shear wall is well; In elastic stage, the hollow shear wall and common shear wall are similar: high stiffness and little deformation; In elastic-plastic stage, the deformation is increasing, and the slit hollow shear wall are divided into several little walls, the property of energy dissipation of hollow shear wall structure is good. The seismic behavior of the slit and integral hollow shear walls are used in the multi-story and low high-rise building.

scholarly journals Seismic Behavior of the Low-rise Shear Wall with CFST Frame and Embedded Steel-plate

2015 ◽  
Vol 9 (1) ◽  
pp. 861-866 ◽  
Author(s):  
Wang Yaohong ◽  
Wu Dingyan ◽  
Cao Wanlin
Keyword(s):  
Seismic Behavior ◽  
Shaking Table Test ◽  
Steel Plate ◽  
Time History ◽  
Shear Wall ◽  
Shaking Table ◽  
History Analysis ◽  
Plastic Stage ◽  
Reduced Scale ◽  
Elastic Stage

In this paper, two low-rise shear wall specimens are tested on the shaking table, one is shear wall with CFST frame and embedded steel-plate, the other one is no concrete outside the steel-plate in comparison of the first one. The reduced scale of the two specimens is 1/12. The seismic wave “Taft” is input in the shaking table test. Based on the experiment, the author conducts the time history analysis (including elastic stage and plastic stage) of the specimens. The calculated results and measured results are compared.

scholarly journals Analytical model of bolt shear resistance considering progressive yield of surrounding material

2022 ◽  
Vol 4 (2) ◽  
Author(s):  
Chen Wen-qiang ◽  
Li Yi-jia
Keyword(s):  
Analytical Model ◽  
Reaction Force ◽  
Nonlinear Behavior ◽  
Friction Angle ◽  
Analytical Models ◽  
Material Strength ◽  
Dilation Angle ◽  
Installation Angle ◽  
Plastic Stage ◽  
Elastic Stage

AbstractExisting analytical models usually fail to match with the actual conditions due to ignoring the nonlinear behavior of the surrounding material reaction force, which changes progressively with the joint shear displacement from elastic stage to yield stage. To tackle this problem, this study proposes a new analytical model to describe the bolt deformation and bolt contribution from elastic stage to plastic stage. The developed model is verified by available experimental direct shear tests of bolted joints and compared with existing models. Then, based on this model, the effects of the joint dilation angle, the bolt installation angle, the friction angle, and the surrounding material strength on bolt contribution are also analyzed and its implication is further discussed. Our results show that the proposed model can precisely describe the evolution of bolt contribution from elastic stage to plastic stage. Compared with surrounding material strength, the augmentation of the joint dilation angle and friction angle is more beneficial to increase the bolt contribution and the optimal installation angle. The work presented is to attempt to provide a reference for the understanding of bolting mechanism of jointed rock mass, the development of bolting theories and the practice of bolting engineering.

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