Inner Force Analysis of Two Typical Frames with Vertical Displacement

2008 ◽  
Vol 400-402 ◽  
pp. 341-346
Author(s):  
Wei Zhou
Keyword(s):  
External Load ◽  
Bending Moment ◽  
Simple Calculation ◽  
Basic Structure ◽  
Vertical Displacement ◽  
Internal Force ◽  
Moment Redistribution ◽  
Calculation Results ◽  
Vertical Chain ◽  
Force Calculation

Finite element method is often used to obtain exact solution in the course of internal force calculation of some complex frames which contain nodal vertical displacement such as frames with transferring layer and mega-frames with sub-structure. In the phase of scheme comparison and schematic design, methods which can quickly produce calculation results of the above said frameworks are necessary. Based on the basic principle of displacement method, this paper proposes a simple analytical method for frameworks that contain nodal vertical displacement. According to the proposal, the basic structure for calculation is the framework in which is added vertical chain-pole at relevant node; the basic unknown quantities are the nodal vertical displacement of the basic structure; the basic equation is fixed according to the equilibrium of node forces; unit vertical displacement as well as bending moment and shear diagram of the basic structure under external load are respectively obtained by using moment redistribution method; nodal vertical displacement is determined through substitution of shear force of relevant rod into the equilibrium equation of the chain-pole node; the actual internal force is determined through superposition of actual vertical displacement and internal force diagram algebra of the basic structure under vertical external load. An engineering example is introduced, which is intended to provide reference for the simple calculation for the above said complex frameworks.

Internal Force Calculation of Two-Way Curved Arch Bridge

2012 ◽  
Vol 594-597 ◽  
pp. 1561-1564
Author(s):  
Bao Rong Huo ◽  
Guang Ning Yang ◽  
Xiang Dong Zhang
Keyword(s):  
Bending Moment ◽  
Internal Force ◽  
Arch Bridge ◽  
Traffic Capacity ◽  
Moment Distribution ◽  
Bridge Structures ◽  
Calculation Results ◽  
Load Simulation ◽  
Force Calculation ◽  
Main Arch

Because of two-way curved arch bridge with low design load, less structural steel, improper construction, overloading and poor integrity, when the bridge structure can’t satisfy the carrying capacity and traffic capacity requirements, we urgently need reinforce the bridge, which has become an important link of safety assessment and insurance of the bridge structures. Internal force calculation of two-way curved arch bridge is done, and calculation conclusions of Aohan Bridge are shown. Plane rod unit’s calculation results show that the bridge under the action of steam-20, hang-100 loads, eccentricity of the section at the arch feet in main arch ring beyond allowable eccentricity, a state of large eccentric's stress appears, and on surface of the arch feet appeared tensile crack in the load simulation. The calculation results of the main arch ring shows that a phenomenon of stress concentration exists in the arch feet, in addition to the influence of big eccentric. Technology processing should be considered when do the arch feet reinforcement. Data from the arch ring calculation results, the bridge has certain overload potential. But according to the bending moment distribution, strengthen the resistance bending moment in the arch feet, an allow full play to the potential of concrete iron in the arch rib under the premise of reinforced the positive bending moment.

scholarly journals Moment redistribution in continuous prestressed concrete box girder with corrugated steel webs

2019 ◽  
Author(s):  
Jin-Sheng Du ◽  
Pui-Lam Ng ◽  
Xiang Ma ◽  
Jian Wang
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Prestressed Concrete ◽  
Concrete Strength ◽  
Bending Moment ◽  
Element Model ◽  
Box Girder ◽  
Moment Redistribution ◽  
Calculation Results ◽  
The Moment

A fibre-finite-element model of continuous prestressed concrete (PC) composite box girder with corrugated steel webs is established with force-based elements using OpenSees. After the model is validated with existing experimental data, the effects of reinforcement index in upper and lower flanges, effective prestress and concrete strength on the moment redistribution behaviour is analysed. It is shown that increasing the reinforcement index in lower flange or effective prestress can increase the amount of bending moment redistribution, whereas increasing the concrete strength or reinforcement index in upper flange can decrease the amount of bending moment redistribution. By inspecting the sensitivity of parameters, it is found that the reinforcement index in lower flange has the most significant influence on the moment redistribution, followed by the concrete strength and then by the effective prestress, while the reinforcement index in upper flange has only little impact on the moment redistribution. The calculation results are compared with the existing formulas. Finally, a moment redistribution formula is proposed for continuous PC box girder with corrugated steel webs.

Analysis of Large-Span Steel Concrete Railway Arch Bridge Suspender Tension

2013 ◽  
Vol 361-363 ◽  
pp. 1259-1263 ◽  
Author(s):  
Jia Lin Xu
Keyword(s):  
Bending Moment ◽  
Internal Force ◽  
Steel Tube ◽  
Force Balance ◽  
Initial Tension ◽  
Finite Element Program ◽  
Arch Bridge ◽  
Reverse Sequence ◽  
Element Program ◽  
Force Calculation

In this paper the concrete-filled steel tube concrete arch bridge as the research object, through the finite element program MIDAS, analyzes the internal force of the whole bridge, determined the distribution of internal force and the most unfavorable position; Using the force balance method, taking the reasonable stress of the bending moment status to control goals, determines the boom of the bridge as the condition of reasonable internal force; Use fall down method, according to the reverse sequence in order to cut the boom, each cut as a model for internal force calculation and analysis, get the next will be cut derrick's internal force, its value is the order construction boom of the initial tension.

Engineering Design and Analysis for Four-Legged Steel Trellis Column

2010 ◽  
Vol 44-47 ◽  
pp. 1500-1504
Author(s):  
Jian Bin Chen ◽  
Hai Jun Xue
Keyword(s):  
Engineering Design ◽  
Design Process ◽  
Design Method ◽  
Bending Moment ◽  
Internal Force ◽  
Axial Pressure ◽  
Length Width ◽  
The Stability ◽  
Force Calculation

In this paper, the design process of the four-legged steel trellis column is introduced for an actual project. The internal force calculation including of axial pressure and bidirectional bending moment are discussed. The strength and stability satisfy the requisition by code. Confirm that the stability of sub pillar is key element for design of trellis column. The simulations show that the design method is safety and reasonable by STAAD.pro software. Different gridding is chosen based on length, width and thickness of members; excess larger or smaller gridding is improper. The conclusions and methods can be referred by later engineering.

Analysis of Dynamic Characteristics of Pile-Soil Coupling Effect in Consideration of Large Span Cable-Stayed Bridge

2014 ◽  
Vol 501-504 ◽  
pp. 1270-1273
Author(s):  
Wen Yuan Chen
Keyword(s):  
Axial Force ◽  
Soil Structure ◽  
Coupling Effect ◽  
Reaction Force ◽  
Bending Moment ◽  
Internal Force ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Pile Cap ◽  
Force Calculation

Using the viscouselastic artificial boundary, three conditions of long-span cable-stayed bridge are analyzed,such as pile cap consolidation, pile - structure and pile soil structure interaction. Natural frequency of bridge of pile - soil - structure coupling becomes small and cycle becomes long. The pile bottom reaction force decreased obviously, at the same time, the axial force , bending moment, axial force of cable, tower of axial force and bending moment is also reduced significantly. Cable-stayed bridge is a special flexible structure, so, static internal force calculation in the tower bottom consolidation pattern is safe, but the value is too large.

scholarly journals Predicting Response of Constructed Tunnel to Adjacent Excavation with Dewatering

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Panpan Guo ◽  
Feifei Liu ◽  
Gang Lei ◽  
Xian Li ◽  
Cheng-wei Zhu ◽  
...  
Keyword(s):  
Water Level ◽  
Shear Force ◽  
Bending Moment ◽  
Vertical Displacement ◽  
Internal Force ◽  
Specific Yield ◽  
Additional Stress ◽  
Initial Water ◽  
Plan View ◽  
Maximum Shear Force

This paper proposes a new method for predicting the displacement and internal force of constructed tunnels induced by adjacent excavation with dewatering. In this method, the total excavation-induced additional stress on the constructed tunnel is derived by superposing the additional stresses induced by excavation unloading and dewatering effects. The additional stress induced by unloading effect is calculated using Mindlin’s solution. The additional stress induced by dewatering effect is calculated using the principle of effective stress and the Dupuit precipitation funnel curve. With the beam on elastic foundation method, the total additional stress is then used for calculating the tunnel displacement and internal force caused by adjacent excavation with dewatering. Based on three well-documented case histories, the performance of the proposed method is verified. Moreover, a parametric analysis is also performed to capture the effects of excavation depth, tunnel-to-excavation distance, initial water level, excavation plan view size, and specific yield on the responses of the constructed tunnels. The results indicate that the effect of excavation depth on the tunnel maximum vertical displacement, maximum bending moment, and maximum shear force is more significant at an excavation depth greater than the cover depth of the constructed tunnel. The tunnel maximum vertical displacement, maximum bending moment, and maximum shear force decrease nonlinearly with an increase in the tunnel-to-excavation distance and the initial water level. Among the investigated parameters, the excavation dimension in the tunnel longitudinal direction affects most the tunnel responses. The effect of specific yield on the tunnel displacement and internal force induced by adjacent excavation with dewatering becomes more obvious as increasing the initial water level and excavation depth.

Internal Force Calculation Method of the Steel Portal Frames with End-Plate Bolted Connections

2011 ◽  
Vol 94-96 ◽  
pp. 564-570
Author(s):  
Xiu Li Liu ◽  
Yan Wang
Keyword(s):  
Finite Element ◽  
Internal Force ◽  
Finite Element Calculation ◽  
Element Calculation ◽  
Bolted Connections ◽  
Initial Stiffness ◽  
End Plate ◽  
Calculation Results ◽  
Simplified Calculation ◽  
Force Calculation

Simplified calculation of initial stiffness of end-plate bolted connections is given in the paper. Considering the influence of the end-plate bolted connections to the internal force of the steel portal frames, the modified elastic calculation of internal force is suggestted. Comparing with the finite element calculation results of different span steel portal frames, the calculated value is agree with the finite element calculation results. End-plate bolted connections are semi-rigid connections, and the flexibility of the connections affects the behavior of the frames, the internal force of rigid frames should be modified when semi-rigid connections used. The modified elastic calculation of internal force of the steel portal frames with end-plate bolted connections is simple and has good agree with the finite element results, which can give reference to engineering design.

scholarly journals Mechanical Characteristic Analysis of Buried Drainage Pipes after Polymer Grouting Trenchless Rehabilitation

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jian-guo Xu ◽  
Zhi-hao Chen ◽  
Ren Wang
Keyword(s):  
Mechanical Properties ◽  
Bending Moment ◽  
Work Conditions ◽  
Internal Force ◽  
Characteristic Analysis ◽  
Buried Pipelines ◽  
Winkler Model ◽  
Calculation Results ◽  
Experimental Values ◽  
Polymer Interaction

The application of polymer grouting in underground pipeline rehabilitation is increasing gradually. The leakage and subsidence of buried pipelines could be repaired by polymer grouting technology. In order to analyse the calculation theory of the pipeline repairing process, the Winkler model and the Vlazov model of the pipe-soil-polymer interaction based on the elastoplastic theory are established, the calculation formulas of the pipe-soil interaction under polymer grouting are derived, and the MATLAB calculation program based on the transfer matrix method is compiled. Then the calculated values are compared with the pipeline experimental values, and the influence of different factors on the internal force and deformation of the polymer-repaired pipeline under different work conditions is discussed. The results show that the values and trends of the pipe deformation and circumferential bending moment calculated by the models are consistent with the experimental results, and the results obtained by the Vlazov model are closer to the experimental values. In addition, the void at the bottom of the pipeline has a large impact on the mechanical properties of the pipeline. However, polymer grouting can repair disengaged pipelines effectively and restore their mechanical properties. The proposed methods and calculation results are valuable for pipeline polymer repairing analysis and pipeline void repairing design.

scholarly journals Analytical Method for Geometric Nonlinear Problems Based on Offshore Derricks

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 610
Author(s):  
Chunbao Li ◽  
Hui Cao ◽  
Mengxin Han ◽  
Pengju Qin ◽  
Xiaohui Liu
Keyword(s):  
Analytical Method ◽  
Bending Moment ◽  
Nonlinear Problems ◽  
Weather Conditions ◽  
Order Effect ◽  
Practical Calculation ◽  
Geometrically Nonlinear ◽  
Uniform Load ◽  
Safety Research ◽  
Calculation Results

The marine derrick sometimes operates under extreme weather conditions, especially wind; therefore, the buckling analysis of the components in the derrick is one of the critical contents of engineering safety research. This paper aimed to study the local stability of marine derrick and propose an analytical method for geometrically nonlinear problems. The rod in the derrick is simplified as a compression rod with simply supported ends, which is subjected to transverse uniform load. Considering the second-order effect, the differential equations were used to establish the deflection, rotation angle, and bending moment equations of the derrick rod under the lateral uniform load. This method was defined as a geometrically nonlinear analytical method. Moreover, the deflection deformation and stability of the derrick members were analyzed, and the practical calculation formula was obtained. The Ansys analysis results were compared with the calculation results in this paper.

scholarly journals Internal Force on and Deformation of Steel Assembled Supporting Structure of Foundation Pit under Thermal Stress

2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
High Strength ◽  
Element Model ◽  
Internal Force ◽  
Foundation Pit ◽  
Dimensional Finite Element ◽  
Influence Of Temperature On ◽  
Scale Experiment ◽  
Three Dimensional Finite Element

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.

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