Applied Mechanics and Materials Vols. 268-270

Abstract: This study focuses on the influential factors that enhance the reliability and versatility of structure throughout the life span. The factors are considered on the basis of the need for assessment of state of –art- structural analysis and design. Through investigation the researcher found that there are two most influential factors are repeatedly influencing the life of structure. The two factors are structural elements and loading patterns. Structural elements are identified on the basis of structure height, span, bays, percentage of shear wall, ratio of structural and non- structural panels to total number of panels and type of frame. The loading pattern investigated on the serviceability limit of structural components.

Abstract: This paper carries out dynamic tests of self-compacting prestressed concrete beams, 10 simply-supported and 5 free, then simulates modal analyses. It shows that, via comprehensive analyses of the first four natural frequencies and modes, the simple support can not achieve the ideal confinement effect for dynamic tests. Especially the tested high frequencies and modes are obviously different from corresponding theoretical values, instead the same as elastic-supported beams. The support plays the role of elastic one. The conclusions will provide meaningful references to further researches on prestressed concrete beams such as improving the accuracy of tests, dynamic analyses and theoretical frequency calculation.

Abstract: A new type of anti-tension device was put forward. One specimen on three utlimate working conditions was analyzed by FEM. The research results showed that there was large eccentricity between the upper steel frame and the lower steel frame in the horizontal plane, the maximum bearing capacity of the device would decrease to some extent, especially in two direction eccentricity condition. In the Sap2000 program, the characteristic of the device met with that of Hook element, some parameters of the model had been identified. Hook element could model this device when it was on the elastic stage.

Abstract: A new type of anti-wind device was put forward. 1/4 scale model about it had been tested and analyzed by FEM. Comparison of FEM, design calculation results with test results also had been done.Test and FEM results show the intermediate section will be the most weakness part, no matter that it is on the condition of in-plane load or out-plane load. During the stage of anti-wind design, it is safe for the FEM, design calculation results in which the standard strength of material is used, but at the stage of seismic design, the ultimate strength of anti-wind device should be considered in order to assure the anti-wind device to damage while earthquake happens.

Abstract: FEM is use for the mechanical analysis of reinforced retaining wall under earthquake loading. The main results are as following. The displacement and axial force increased with the increased seismic intensity. The displacement and axial force decreased with the increased the length of bar strip. The displacement and axial force decreased with the decreased the spacing of bar strip. The displacement and axial force decreased with the increased physical mechanics parameters of filling. Seismic response was similar under bilateral seismic loading and horizontal seismic loading, seismic response was slightly larger under bilateral seismic loading.

Abstract: This study describes the analysis and design process of shear wall construction, which is applied in various types of building construction. Shear walls resist lateral forces viz. earthquake force and wind force for high-rise structure and gravity load for all type of structure. Besides, Buildings with cast-in-situ reinforced concrete shear walls are widely used in earthquake-prone area and regions in the world. Research methods were confined to library research and employed software for analysis. The analytical accuracy of complex shear wall system have always been of concern to the civil and structural Engineering system. The software of this system is performed on the platform of modelling and then, the system models are usually idealized as line elements instead of continuum elements. Single walls are modelled as cantilevers and walls with openings are modelled as pier/ spandrel systems. In order to find the stiffness, the simple systems models can provide reasonable results. It has always been accepted that a scale based model in the FEM is exact and justifiable.

Abstract: Making use of internal variables and a proper generalized time scale to describe the irreversible deformation history of salt rock, a constitutive model coupled of creep deformation and damage development of salt rock is formulated. A creep correlated function is defined to describe the effect of loading time on creep deformation of salt rock, and a fourth order damage tensor is introduced to formulate the anisotropic development of material damage. The creep experiments of salt rock under triaxial compression are simulated by the proposed constitutive model. The good agreement between the calculated and experimental results shows the proposed constitutive model can well describe the creep behavior of salt rock.

Abstract: The length of the pre-splitting crack is an important parameter in underground mine deep-hole blasting, and experience and engineering analogy methods are used commonly, but they seldom have scientific and theoretical basis. In this paper, the mature numerical analysis software — ANSYS/LS-DYNA was adopted, the different lengths of pre-splitting crack were simulated. In the filling body, the corresponding maximum blasting vibration velocity and stress are obtained by numerical simulation when the maximum initiation section blasted. The corresponding regression formulas are obtained by using the least square method, and the optimal length of the pre-splitting crack is 12 m through the calculation. Proved by practice, this method to get the length of the pre-splitting crack is scientific and effective, can be extended in other similar blasting engineering.

Abstract: With the prolonged production term and the stimulation of the oil well in oil-field, the load which results from the in-situ stress is one of the main reasons to the casing damage. Taking the casing in Cementing section, the cement and the rock surrounding the cement into consideration, a mechanical model is established, while analytical solutions of displacement and stress distribution is obtained. The finite element method is adopted to obtain the numerical solutions of the mechanics model. The result shows that analytical solutions and finite element solutions are approximate. Finite element model of casing/cement/formation which is established in the paper can be used to analyze the load and stress distribution of worn casing with non-uniform in-situ stress.

Abstract: The passive earth pressure on the both sides of a sheet pile retaining wall is owing to plasticity bounded, a fact that affects the horizontal loading capacity of the wall. In order to find out a method, that the loading capacity of the wall can be analytically calculated and the mentioned constrain could be token into account, the paper set up a DIMSP model, which consists of mechanics equilibrium principle including two inequalities for the plasticity condition of earth pressure. The deduced solution of the model is capable of calculating the bearing capacity, and possesses the advantages of no additional correction of the cut in depth of the wall. Further more the continuity of earth pressure distribution is ensured by this model, an adjustment of the earth pressure figure is also without difficulty possible. For engineering application some graphics are given, the cut in depth of the wall can be read from them conveniently.