A Fiber Model-Based Calculation Method for Shrinkage and Creep of Giant Composite Members

A technology of combined components and calculation methods, applied in calculation, special data processing applications, instruments, etc., can solve problems such as outdated concrete shrinkage and creep prediction models, difficult loss of concrete moisture, and uneven deformation of vertical components

Active Publication Date: 2015-11-25
TONGJI UNIV ARCHITECTURAL DESIGN INST GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For the design of engineering structures, there are currently three problems: one is that the selected concrete shrinkage and creep prediction model is outdated, and the prediction value is not accurate; the other is that part of the concrete is in a closed state and dried out due to the lack of consideration of the restraint of the steel reinforcement on the concrete. less, the shrinkage and creep will be uneven, which will affect the overall shrinkage and creep value of the component; third, the effect of eccentric load is not considered in the process of vertical deformation, and the bending moment generated by eccentric load will also cause uneven deformation of the vertical component. Influence of Secondary Bending Moments on Horizontal Members
Composite section steel generally contains a closed area, so that the concrete inside is in a closed state, making it difficult to lose moisture in the concrete, the relative humidity is high, the drying shrinkage and drying creep strain are very small, and the creep strain on the section of the member is uneven. Then affect the overall shrinkage and creep value of the component
At the same time, the structural form of super high-rise structures is generally retracted upwards, which will produce continuous eccentric pressure under the action of other constant loads such as self-weight. Horizontal members create additional internal forces

Method used

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  • A Fiber Model-Based Calculation Method for Shrinkage and Creep of Giant Composite Members
  • A Fiber Model-Based Calculation Method for Shrinkage and Creep of Giant Composite Members
  • A Fiber Model-Based Calculation Method for Shrinkage and Creep of Giant Composite Members

Examples

Experimental program
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Effect test

Embodiment 1

[0060] Such as figure 1 As shown, a calculation method for shrinkage and creep of giant composite members based on the fiber model, this method takes into account the influence of the steel skeleton in the member on the concrete, part of the concrete is in the closed steel skeleton, the relative humidity is high, and the drying shrinkage and creep The strain is small, which is different from the shrinkage and creep parameters of the concrete exposed to the air. The calculation is considered separately, and the final deformation is coordinated according to the assumption of the plane section, including the following steps:

[0061] The first step is to divide the giant composite member into fiber units according to the material composition, creep parameters and force characteristics of the composite member section, and calculate the centroid and area of ​​each fiber unit.

[0062] The law of fiber unit division for giant composite components is as follows:

[0063] a) Concrete...

Embodiment 2

[0131] The hypothetical conditions of parameters such as the cross-section and material of the giant column selected in this embodiment are the same as those in Example 1.

[0132] 1. Assumptions

[0133] The section force of the present embodiment is: P=100MN, M x =30MN·m, M y =50MN·m.

[0134] 2. Calculation process and results

[0135] (1) Divide fiber units. In the case of eccentric compression, the section should be evenly divided into multiple fiber units, and the inner concrete, outer concrete and steel should be divided into fiber units separately. The specific division and labeling of cross-sectional fiber units are as follows: Figure 5 shown.

[0136] (2) Calculate the elastic strain value of the fiber unit. Extract the data such as the area, centroid, and elastic modulus of the fiber unit, and calculate the section stiffness matrix K according to formula (4) s , calculate the elastic strain ε of the section according to the internal force on the section and...

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Abstract

The invention relates to a giant combined component shrinkage and creep computing method based on a fiber model. The computing method includes the following steps: 1), performing fiber unit division on a giant combined component according to material composition, creep parameters and loading features of a section of the combined component, and computing the centroid and the area of each fiber unit; 2), computing the initial elastic strain and the stress of each fiber unit according to the internal force and material characteristics of the section; 3), computing a shrinkage and creep value of each fiber unit according to the initial stress of each fiber unit and a shrinkage and creep model, and superimposing the shrinkage and creep value and the elastic strain of each fiber unit to obtain a total dependent variable of each fiber unit; and 4), computing the virtual stress of each fiber unit, performing integrals to obtain the virtual internal force on the section, and computing the total dependent variable of the section of the giant combined component through the virtual internal force. Compared with the prior art, the giant combined component shrinkage and creep computing method based on the fiber model has the advantages of being simple in computing process, accurate in computing results and the like.

Description

technical field [0001] The invention relates to an analysis and calculation method of a building structure, in particular to a fiber model-based calculation method for shrinkage and creep of a giant composite component. Background technique [0002] At present, the super high-rise buildings in China generally adopt the lateral force-resistant structural system of giant frame-core tube-outrigger truss, and giant vertical components such as giant columns in the giant frame and shear walls in the core tube bear large vertical forces. , the cross-sectional size is huge, and in order to better meet the requirements of bearing capacity and axial compression ratio, the giant vertical members generally use steel and concrete composite members. [0003] In addition to the load action, the giant composite member is also subject to non-load action, mainly including shrinkage and creep of concrete, structural temperature change, and differential settlement of the foundation. Non-load e...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): G06F17/50
Inventor赵昕姜世鑫郑毅敏周瑛
OwnerTONGJI UNIV ARCHITECTURAL DESIGN INST GRP CO LTD