Multi-ribbed Slab Research Articles

Homogenization-Based Investigation on Equivalent Constitutive Relationship of Multi-Ribbed Slab Wall

Multi-ribbed slab structure (MRSS) is a new structural system developed in recent years, with multi-ribbed slab wall as its main bearing member, which was an orthogonal anisotropic solid constituted by reinforced concrete ribs, frame and embedded solid body. It was suggested to employ asymptotic expansion-based homogenization method to establish the equivalent homogenized model. The method is that it considers the impact of rib relative width and the possion. The research results showed that: the macroscopic constitutive relationship of multi-ribbed wall based by the method has certain accuracy, can provide basis for multi-ribbed slab structure FEM analysis.

Calculation and Analysis of Composite Wall Frame by Finite Element

The lightweight frame structure with Multi-ribbed slab is a new energy-efficient residential architecture. The Multi-ribbed composite wall of the frame structure plays an important role as the main bearing components. This paper mainly discussed the mechanical performance of composite wall. A simplified frame-plane model was built based on the theoretical analysis of the composite wall. The professional calculating program has been designed and written by FORTRAN, and the calculation and analysis of the typical model has been completed with the program. Finally, the frame-plane simplified model was further calculated and analyzed by ANSYS. The method used in this paper may open a new approach for simulating and analyzing the mechanical performance in engineering practice and the result we got may provide some theory basis for the application of Multi-ribbed slab frame structure.

Research on Out-Plane Bending Stiffness of Multi-Ribbed Slab Structure

Floor loads of the large-bay floor can cause larger bending moment at the floor edges. So the shear-wall need to bear greater out-plane bending moment and this problem can not be ignored. multi-ribbed slab structure is a new wall. The paper Calculated out-plane bending-stiffness of multi-ribbed slab by using the equivalent-stiffness method. The results show that: the equivalent stiffness method is simple and ribbs should not be too large, width-height ratio control between 1 and 3, wall length is about 5.4m.

The Application of Straw Concrete Wall Board in Constructional Engineering

Constructional engineering was always faced with the threaten of earthquake and the problem of large energy consumption. As a new type of green building material, straw concrete has better ductility than normal concrete. In the straw concrete multi-ribbed slab structure, as the filling material of wall board, straw concrete improved the energy dissipation and deformability of wall board. When the load was applied, the filling blocks, grid frame and outer frame in straw concrete wall board work cooperatively, have good mechanical properties. The straw concrete wall board has advantages that light, high strength, energy conservation and seismic resistance. Considering the effect of different components in straw concrete wall board, this paper proposes the formula of vertical bearing capacity of straw concrete wall board to provide the basis for engineering application. The construction of straw concrete multi-ribbed slab structure include three processes that steel bar bind, blocks prefabrication and integral pouring, which fits for field fabrication in the building construction site.

Study on the Effect of Blocks on Seismic Performance of Improved Multi-Ribbed Slab Structure

In order to confirm the calculation model of multi-ribbed slab structure and transmission of earthquake action, this paper improved existing multi-ribbed slab structure. The calculation model of improved multi-ribbed slab structure confirmed the stress relationship among three seismic fortification lines, and the transmission of earthquake action became clear, the same calculation model could be applied in structural analysis. For studying the features of characteristic parameters of restoring force changing in the first seismic fortification line, blocks, and correcting the parameters, the experimental study was carried out. The experiment shows that when a unidirectional horizontal load was applied, that blocks in grid frame could be regarded as a slanted strut that with specific section and elasticity, the ideal slanted struts nominal elastic modulus is roughly in 20~60 N/mm2.

Study on the Effect of Outer Frame on Seismic Performance of Improved Multi-Ribbed Slab Structure

This paper confirmed the calculation model of improved multi-ribbed slab structure and the stress relationship among three seismic fortification lines, offered the possibility of distributing earthquake action reasonably, provided the basis for optimal design. Comparing the similarities and differences between the improved multi-ribbed slab structure and energy-consumption braced frame; characteristic parameters of restoring force in the third seismic fortification line, outer frame, would be got by design and be adjusted. This paper analyzed the third seismic fortification line by numerical simulation and example analysis, the variation range of performance of the third seismic fortification line is got, this range can be adjusted by changing the influencing factors of three seismic fortification lines. The reasonable destruction mode of three seismic fortification lines could be achieved, namely the control design of three seismic fortification lines could be achieved.

Study on the Effect of Grid Beam on Seismic Performance of Improved Multi-Ribbed Slab Structure

In order to confirm the calculation model of multi-ribbed slab structure and transmission of earthquake action, this paper improved the existing multi-ribbed slab structure. The calculation model of improved multi-ribbed slab structure confirmed the stress relationship among three seismic fortification lines, and the transmission of earthquake action became clear, this calculation model could be applied in structural analysis. For studying the effect of characteristic parameters of restoring force changing in the second seismic fortification line on seismic performance, and correcting the parameters of grid beam, this paper analyzed push-over model of the second seismic fortification line to get the static pushover curve. According to the study, the amount of steel bar in grid beam and sectional dimension of grid beam made the major effect on characteristic parameters of restoring force in the second seismic fortification line, concrete grade of grid beam is a unconsidered factor. Nominal elastic modulus of filling materials didnt much affect the yield strength and yield displacement of the second seismic fortification line, but made significant effect on post-yield strength.

Study on the Effect of Grid Column on Seismic Performance of Improved Multi-Ribbed Slab Structure

In order to confirm the calculation model of multi-ribbed slab structure and transmission of earthquake action, this paper improved existing multi-ribbed slab structure. The calculation model of improved multi-ribbed slab structure confirmed the stress relationship among three seismic fortification lines, and the transmission of earthquake action became clear, the same calculation model could be applied in structural analysis. For studying the effect of characteristic parameters of restoring force changing in the second seismic fortification line on seismic performance, and correcting the parameters, this paper analyze push-over model of the second seismic fortification line to get the static pushover curve. According to the study, the amount of steel bar in grid column and sectional dimensions of grid beam made the major effect on characteristic parameters of restoring force in the second seismic fortification line. The growth of steel bar’s sectional area in grid framework and the yield strength are mainly in direct proportion. It is more reasonable that simultaneously alter steel bar’s sectional area in grid frame and dimensions of grid framework to adjust characteristic parameters of restoring force changing in the second seismic fortification line.

Pseudo-Dynamic Tests and Numerical Analysis of Multi-Ribbed Slab Structure

Pseudo-Dynamic Tests and Numerical Analysis of Multi-Ribbed Slab Structure

Finite Element Model and Numerical Simulation of Multi-ribbed Slab Structure

Finite Element Model and Numerical Simulation of Multi-ribbed Slab Structure

Application of Formwork Technology in Engineering

Installing and dismantling the formwork are not easy in cast-in-situ multi-ribbed slab construction,the formwork technology overcomes the difficult problem.This paper mainly introduces the construction technology and quality standards of the plastic formwork.Through the engineering practice,the author sums up the advantages of this technology.

Pseudo-Plate Method of High-Strength Steel Fiber Concrete Multi-Ribbed Slab

Basing on the disadvantages of multi-ribbed slab in practice, a new high-strength steel fiber concrete (HSFC) composite multi-ribbed slab structure is introduced. Because adding steel fibers can improve the capacity of the concrete, it also can make some influence on the mechanic performance of HSFC multi-ribbed slab, such as elastic module, shear module, flexural rigidity, and torsion rigidity and so on. So by the analysis of the material and mechanic capacity and considering the influence of steel fiber, the formulas to calculate flexural rigidity, torsion rigidity, deflection and internal force of the new composite slab are given, in which the multi-ribbed slab is equivalent to orthotropic slab by the principle of stiffness coincidence. The study in this paper can provide some valuable theory references for further study and application of multi-ribbed slab.

The Application Research of Reinforced Concrete Multi-Ribbed Hollow Composite Slab in the Road Slab Culvert

Reinforced concrete cover in the road culvert cover design, in order to facilitate the construction, usually using precast reinforced concrete solid slab, but the overall cost is not low. This article researched a reinforced concrete multi-ribbed hollow composite slab, it based on the theory of reinforced concrete multi-ribbed slab structures, using a precast reinforced concrete ribbed slab as the bottom die, then poured reinforced concrete beams and panels rib ,and them constituted a whole stack of reinforced concrete ribbed hollow slab. This kind of cover, compared with the precast reinforced concrete solid cover, is not only good mechanical properties, high integrity, but also saving concrete, steel, and bottom slab appeared smooth and fine, lower construction cost.

Study on Nonlinear Finite Element Analysis Method of Multi-Ribbed Composite Slab Structure Containing Steel Fibers

Steel fiber concrete multi-ribbed composite slab system includes material composite and structure type composite, which has good mechanical and thermal insulation properties. This paper presents an assessment of the structure investigated using three-dimensional nonlinear finite elemental analysis. The analysis firstly has focused on solving the constitutive relation of the materials and the effect of steel fiber to determine the finite element simulation. Moreover nonlinear finite element analysis for the mechanical properties of the whole process on the composite structure system has been presented in this paper, and by changing the fiber volume fractionvf(0%, 1%, 2% and 3%) the parameter has been discussed. The analysis results show that stress distributions of the structure are close for different concrete strength and steel fiber volume fraction before formation of the plastic hinge lines of the upper edges. When the structure began to crack and the plastic hinge lines of upper edge gradually formed, due to the influence of the redistribution of internal forces, the steel fiber volume fraction has significant impact for the mechanic behavior of the structure. In addition, the steel fiber volume fraction on the developing and distribution of the cracks has little effect. This analysis method and results for the steel fiber concrete multi-ribbed composite structure can provide some valuable references for the structure research and application.

Layered-Shell Element Method of Calculating the Multi-Ribbed Composite Slab’s Elastic Lateral Stiffness

A new method for calculating the elastic lateral stiffness of the multi-ribbed composite slab by ANSYS—the layered-shell element method is introduced in this paper. In the modeling process, there are two ways for establishing the model using element SOLID46: the first refers to regarding the slab as a whole to make arranged layers. While the second type suggests that making arranged layers in each part already separated according to the materials. Especially when there are reasonable hypothesis, the analysis results can guarantee certain precision. By comparison among the two models and the experimental results, no errors with each other have exceeded 5%. The whole model is used for the numerical simulation in view of its briefness. Several factors affecting elastic lateral stiffness are considered, mainly including elastic modulus of the concrete, elastic modulus of the brick, and number of the ribbed-column. From the calculating results, conclusion can be deduced that all of these factors affecting the slab’s stiffness significantly. Along with the factors’ rising, the elastic lateral stiffness of the wall grows up. Basically, the influence factor and the elastic lateral stiffness of the slab present to be linear relationship. It is also meaningful to see that the elastic modulus of the brick plays a very important part in the elastic lateral stiffness of the wall. When compared to the SOLID65 and LINK8 used for the slab’s modeling before, the layered-shell element method is simple in principle, and distinct in conception. Above all, because only one type of element in the finite element analysis is used, it will cost less time when used on building a model of integrated architectural construction.

Research on the Formula of Vibration Period of Multi-Ribbed Composite Slab Structure

As a new structural system with a bright prospect, multi-ribbed composite slab structure has the advantages of ecological materials and seismic performance. In this paper, the formula of vibration period of multi-ribbed composite slab structure is discussed. Based on the analysis of FEM model and the regression analysis of experimental data, an empirical formula was put forward. It has been shown that the calculated results fit well with the test results.

Calculation Analysis on Cracking Load of New Type Composite Wall

New type composite wall is the main bearing member in Multi-ribbed Slab Structure (MRSS), whose cracking load is an important parameter to determine the restoring force model and damage index of the wall. Based on the twin shear unified strength theory, when the influence of intermediate principal stress σ2 and SD effect of materials are considered, the study on low-frequency cyclic lateral loading experiment of wall is proceed and the practical formula for the wall’s initial cracking load is deduced. The practical computing formulas for the wall’s initial cracking load based on twin shear unified strength theory and maximum tensile stress theory are contrastingly analyzed. The results show that, comparing the calculated values based on the twin shear unified strength theory and the values based on maximum tensile stress theory, the former are more closed to the experimental values, and it can provide more accurate, economic and applicable results for practical engineering.

Research on Optimization Design of the Lateral Stiffness Satio about the Frame-Supported Multi-Ribbed Structure

By testing 4 pin standard frame-supported multi-ribbed composite slab’s mechanical proper- ties under the horizontal load’s funtion,it is got that the earthquake resistance performance influence of lateral stiffness satio to frame-supported multi- ribbed slabs.The reasonable value scope of stiffness satio between transformation layers is obtained by finite element analysis of seismic response of frame-support- ed multi-ribbed slab structures and provides theoretical basis to engineering design

Research on the Calculation Method of Vertical Seismic Capacity of the Multi-Ribbed Composite Slab

On the basis of experimental study on 5 standard slabs’ vertical bearing capacity, the paper makes an in-depth analysis on the ratio of axial compression stress to strength, the ratio of height to thickness and the influence of embedded block on the axial bearing capacity of the slabs. By establishing finite element model of the slab, the paper analysis the influence factors by means of numerical simulation and establishing the theoretical calculation formula of the slab. Compared with the experimental results, it is showed that the accuracy of the theoretical calculation formula can meet the practical requirements, which provides theoretical calculation basis for engineering practice.

Research on Methods for Elastic Stiffness of Multi-Ribbed Slab Structure

Considering the influence of the flange and rib column, the equivalent model of multi-ribbed slab is set up by the theory based on the strengthening isotropism fiber. This model is simple, highly precise and strongly applicable through comparing analyzing results with test results. Besides, the calculated formulate is set up on the basis of the whole structural effect and space work, which offers the prerequisite for elastic time history analysis of the structure.