Applied Mechanics and Materials Vols. 204-208

Abstract: The tubular hollow slab inside which GBF high-strength thin-wall pipes are placed is a new type of hollow structure. First the ultimate bearing capacity of tubular hollow continuous slab is measured by experiment. Then the ultimate bearing capacity of the tubular hollow continuous slab is studied by plastic limit analysis method. And the complete solution of structural ultimate load under condition of full internal force redistribution is solved. The study show that the measured values of ultimate load are all a little larger than the theoretical values of ultimate load, which shows that the tubular hollow slab develop full internal force redistribution. So it can be concluded that the tubular hollow slab has fine performance of plastic internal force redistribution.

Abstract: In order to discuss the displacement impact coefficient of the simply supported beam bridge, reinforced-concrete simply supported beam models with different span and different section stiffness are set up using the finite element method in the paper. The maximum dynamic displacement of beam models under the running vehicle is calculated. Combined with the maximum static displacement, the corresponding impact coefficients of models are calculated. At the same time, the modal analysis of beams is conducted to calculate the impact coefficient based on the base frequency. From comparing with the displacement impact coefficient, the bridge spans and section stiffness influence on impact coefficient is analyzed. Results show that the influence of section stiffness on impact coefficient can be ignored, but the influence of the change of span cannot be ignored. It will provide a reference for designing and detection technology of reinforced-concrete simply supported beam.

Abstract: Regular tessellation theory was firstly introduced to deconstruct cells and partition masonry periodically in two dimensions in this paper, the method of regular deconstruction of masonry structures was proposed. In addition, the relationship in mathematical models between the basic cells and RVE was explored, the basic cells and the corresponding RVE boundary and initial conditions was derived.

Abstract: In this study, 2D finite-element study was performed to evaluate the lap spliced length of GFRP rebar of concrete beam designed according to requirements of the current design codes. The analysis models using the general-purpose computer program ABAQUS 6.10-1(2010) are based on the test results of previous researcher. The effects of spliced length and GFRP reinforcement ratio of concrete beam were described in this paper. Total 63 analytical models were considered and nonlinear Finite Element Method (FEM) analysis was conducted. From the analytical results, lap splice length of GFRP rebar was evaluated according to flexural reinforcement ratio.

Abstract: This paper investigates shear flow strength of insulated concrete sandwich panels with glass fiber reinforced polymer (GFRP) shear connectors based on push-out test. The precast insulated concrete panels consist of 60mm concrete wall, 100mm insulation, and 130mm concrete wall. Two concrete walls were connected with GFRP corrugated shear connector. Four specimens with variables such as the insulation type and the width of GFRP corrugated shear connector were made. Failure modes, shear flow-deflection relationships and post-peak strength were investigated. Test results indicate that the specimens with EPS insulation show higher shear flow strength than those with XPSS insulation due to the relatively high surface roughness of EPS insulation, and the shear flow strength increased with increasing shear connector width.

Abstract: In recent years, many large span roofs of airport waiting room and garage were destructed in the tropic storm, which have the characteristics of light mass, high flexibility, slight damping and low natural frequency. Wind loads general control the design of such structures. Thus, the tests of wind pressure with the rigid scale model in boundary layer wind tunnel were conducted in the structural design stage. This paper presents the results of characteristics of wind loads on large-span roof structure of the Guangzhou International Convention & Exhibition Center (GICEC) in frequency domain. The power spectrum densities, correlation coefficients, coherence functions and probability density function (PDF) were analyzed in detail. The results can be summarized as follows: (1)The power spectrum densities of fluctuating wind loads have the characteristics of vortex shedding and the Strouhal number is about 0.295; (2)The coherence coefficients decrease with the frequency and the spatial distance increase at both the along-wind and across-wind direction; (3)There are clearly negative skewed distributions for some pressure taps at the windward leading roof edge and much longer negative tails are observed, which follow Non-Gaussian distributions. The results presented in this paper are expected to be of considerable interest and of use to researchers and professionals involved in designing complex long-span roof structures.

Abstract: Concrete filled steel tubular (CFST) structure is a new type of structure. According to unified theory, hysteretic model of steel beam, reinforced concrete beam and CFST column have been chosen respectively, then nonlinear structural analysis program called IDARC is employed to determine skeleton curve of the CFST frame structure. Results obtained from program are consistent well with those obtained from experiments. Furthermore, some parameters that affect the restoring force model of CFST structure have been studied, including axial compression ratio, steel ratio, material strength and so on. The results not only provide necessary theory basis for popularizing the CFST structure but play a valuable role to seismic design of CFST structure. The contribution described herein outlines a possibility for simulating the seismic behavior of CFST using the nonlinear program called IDARC. The present work offers a simplified approach for establishing the skeleton curves of CFST frames.

Abstract: In this paper, the principle of virtual work to solve the structural displacement, summed up the different types of arc curved bar under different load displacement, which lay the foundation for displacement of the curved bar after the project encountered solving .

Abstract: Being aimed to the earlier temperature crack phenomenon of pier-on mass for concrete box girder during construction caused by hydration. Based on the real engineering, time-dependent effect of concrete density, specific heat and heat conductivity were comprehensively considered, hydration heat attack model was proposed, element birth and dead technique and sub-model technique was adopted to analyze hydration heat temperature field of pier-on mass for pre-stressing concrete box girder. The results indicated that hydration heat attack model is practical, hydration heat temperature at the copulation location of web plate and upper plate and floor plate as well as cross plate is 75°C, gradually decreased from the inner layer to the outer layer; birth and death technology and sub-model technique of element is effective to simulate the layer-cast for pier-on mass of concrete box girder.

Abstract: Based on the theory of breakage mechanics,the structural loess are conceptualized as binary －medium model consisting of bonding brick and frictional band. Shear band is structural loess’ breakage, localization band sprout and development is dynamic process that bonding brick is translating into frictional band.Application of double parameter breakage ratio binary-medium mode of structural loess,simulated the process of structural loess localization band sprouting and expanding with the numerical simulations method,studied localization shear band shape、speciality and law under different disfigurement project,found that the strain localization on a shear band of structural soil at originally is some sets discontinuous little local breakage area step by step developed、 connected and formed the shape of whole destruct with the external load increased,appeared dilatation softening phenomena under the especial disfigurement. Combining binary-medium mode with general finite element,solved the question of localization shear band softening,visual reappeared the course of the local shear band germination and progress.