Applied Mechanics and Materials Vols. 351-352

Abstract: Because of the experiment can only reflect the overall performance of composite slabs under the various parameters combined action, and to ensure the materiality level of one single parameter, ANSYS, one of the finite element analysis software, was used in analogue simulation. According to selected reasonable elements and generated contact elements where between profiled steel sheet and lightweight aggregate concrete, appropriate mathematical model was been built. With full Newton-Raphson method to calculate nonlinear equation, the relevant data and curves were been obtained. Through the comparison between simulation analysis results and experiment results, the mathematical model was verified that it could reflect experiment correctly. These studies could provide assistance in the lightweight aggregate concrete composite slab project finally.

Abstract: In order to study the influence on RC beam fatigue stiffness with different corrosion rates, fatigue load tests have been taken on a set of different corrosion ratios, and the changes in stiffness to the related beams also been calculated based on the deflection of the test beams. And then, the corresponding test analysis is achieved. The results show that: the rate of increase to the deflection of specimen tends to increase and stiffness drastically reduces with the increase in the extent of corrosion under fatigue loads.

Abstract: Based on nonlinear finite element structural analysis method, finite element analysis software of SAP2000 is used in the analysis of middle column divided into two parts on the top the mechanical behavior with prestressed cable for portal frame. In order to consider the effect to force performance, the articulated and rigid in the column base, forking geometric parameters and the cable initial prestressed value parameters of the new structure are studied. The calculation results show that its avail for the frame if the angle of the dividing is thirty. Initial prestressed value of the cable is not the bigger the better and there are different best values in different angles of the bifurcation. In addition, some corresponding design proposal is obtained according to the analysis of the internal force.

Abstract: In order to investigate the effect of temperature (from normal temperature to 850°C) coursed by fire on the strength damage of concrete, thermal compression tests for concrete specimens named C35 have been performed under different temperature conditions. Emphasis is laid on the relationship between temperature and thermal damage strength; and the relevant formula is proposed in this paper. The regularity and mechanism of thermal damage evolution in concrete on strength under high temperature are analyzed. Combined the result of tests with the residual strength thermal damage model, we obtain the specific damage variable value D under different temperatures. Finally, we compare the fitting formula curve to relevant reference; there are some important conclusions which can be partly applied to fire design of concrete structure.

Abstract: The steel-concrete composite ribbed shell is a kind of novel space structure. In this paper, using space beam element and shell element, based on the nonlinear FE theory, considering the elastic-plastic material and geometric nonlinear, in view of the system dynamic response of identifying method, dynamic stability of steel-concrete composite ribbed shell under vertical step loads are studied. Setting up the relationship, it is between load amplitude and dynamic response of the structures, comparing rigid joint with hinge joint on the edge of structure, Critical load conditions of dynamic stability are defined.

Abstract: In masonry structure transformation, due to the removal of walls, force transmission path and force structure mechanism of load-bearing walls will be changed. So it become greatly important to adopt a safe, applicable, economic and reasonable underpinning method. This paper introduces several underpinning methods of masonry structure modification, which summarizes the advantages and disadvantages of them. Their characteristics and using condition are discusses in the paper. Some conclusions which are drawn may be referenced for the future engineering practice.

Abstract: Based on Hamilton principle, the differential equation of free vibration and the corresponding boundary conditions of continuous box girder with consideration for the shear lag effect meeting self-equilibrated stress, shear deformation as well as rotational inertia were induced. The ANSYS finite element solutions were compared with the analytical solutions by calculation examples and the validity of the proposed approach was verified. The obtained formulas developed the shear lag theory. Some meaningful conclusions for engineering design were obtained. The contribution of the shear lag effect decreases each order natural frequency of the continuous box-girder, at the same time the higher the order natural frequency is, the greater the influence of shear lag effect on natural frequency of continuous box-girder is. The shear-lag effect of continuous box girder increases when frequency order rises, and increases while span-width ratio decreases.

Abstract: According to cycle reciprocate loads test on a beam-column connection by top and seat angles with stiffer and double web angles. It is analyzed force performance and failure mode on rib top and bottom of double angle web connection.The results show that: the top and seat angle and angle with two web connected has good ductility and energy dissipation ability.

Abstract: Bored Pile with pile-end pressure grouting technology has been widely used in high-rise buildings and large public buildings in Chinas Inner Mongolia region. Due to this bored pile take a osmosis, filled, replacement, consolidation and consolidation effect, it could have a special role on eliminating the dregs at the pile bottom and the holes hidden trouble between the pile soil and it also enhance the strength of the pile body, increasing the binding power of pile and the soil between the piles. With the result of that, the supporting capacity has a significantly improved and this technology has become the advanced scientific method of reducing the settlement of the pile foundation. By using a high-rise building projects pile example that takes bored piles with pile-end pressure grouting and static loading test, observations and determine the settlement value of the single vertical design capacity analysis methods, it shows that the pile-end pressure grouting bored piles, the layer of sand mixed capacity has been significantly improved.

Abstract: Many elliptical shells are used in structural applications in which the dominant loading condition is axial compression. Due to the fact that the radius varies along the cross-section midline, the buckling behavior is more difficult to identify than those of cylindrical shells. The general concerned aspects in cylindrical shell buckling analyses such as the buckling mode, the pre-buckling deformation and post-buckling deformation are all quite different related to specific elliptical shell geometry. The buckling behavior of elliptical cylindrical shells with uniform thickness has been widely studied by many researchers. However, the thickness around the circumference may change for some specific structural forms, the femoral neck for example, which makes the buckling behavior more complex. It is known that the buckling strength of thin cylindrical shells is quite sensitive to imperfections, so it is natural to explore the imperfection sensitivity of elliptical shells. This paper explores the buckling behavior of imperfect elliptical shells under axial compression. It is hoped that the results will make a useful contribution in this field.